Mathematical Operations: Difference between revisions

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{| align="right"
{| align="right" style="max-width:30%;"
|  __TOC__
|  __TOC__
|}
|}
==Basic and QB64 Numerical Types==
== Basic and QB64 Numerical Types ==
<center>'''QBasic Number Types'''</center>
<center>'''QBasic Number Types'''</center>


* [[INTEGER]] ['''%''']: 2 Byte signed whole number values from -32768 to 32767. 0 to 65535 unsigned. (not checked in QB64)  
* [[INTEGER]] ['''%''']: 2 Byte signed whole number values from -32768 to 32767. 0 to 65535 unsigned. (not checked in QB64)
* [[LONG]] ['''&''']: 4 byte signed whole number values from -2147483648 to 2147483647. 0 to 4294967295 unsigned.
* [[LONG]] ['''&''']: 4 byte signed whole number values from -2147483648 to 2147483647. 0 to 4294967295 unsigned.
* [[SINGLE]] ['''!''']: 4 byte signed floating decimal point values of up to 7 decimal place accuracy. '''Cannot be unsigned.'''  
* [[SINGLE]] ['''!''']: 4 byte signed floating decimal point values of up to 7 decimal place accuracy. '''Cannot be unsigned.'''
* [[DOUBLE]] [#]: 8 byte signed floating decimal point values of up to 15 decimal place accuracy. '''Cannot be unsigned.'''
* [[DOUBLE]] [#]: 8 byte signed floating decimal point values of up to 15 decimal place accuracy. '''Cannot be unsigned.'''
* To get '''one byte''' values, can use an [[ASCII]] [[STRING]] character to represent values from 0 to 255 as in [[BINARY]] files.
* To get '''one byte''' values, can use an [[ASCII]] [[STRING]] character to represent values from 0 to 255 as in [[BINARY]] files.
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* [[_BYTE]] ['''%%''']: 1 byte signed whole number values from -128 to 127. Unsigned values from 0 to 255.
* [[_BYTE]] ['''%%''']: 1 byte signed whole number values from -128 to 127. Unsigned values from 0 to 255.
* [[_INTEGER64]] ['''&&''']: 8 byte signed whole number values from -9223372036854775808 to 9223372036854775807
* [[_INTEGER64]] ['''&&''']: 8 byte signed whole number values from -9223372036854775808 to 9223372036854775807
* [[_FLOAT]] [##]: currently set as 10 byte signed floating decimal point values up to 1.1897E+4932. '''Cannot be unsigned.'''
* [[_FLOAT]] [##]: currently set as 10 byte signed floating decimal point values up to +/-1.189731495357231765F+4932. '''Cannot be unsigned.'''
* [[_OFFSET]] [%&]: undefined flexable length integer offset values used in [[DECLARE DYNAMIC LIBRARY]] declarations.  
* [[_OFFSET]] [%&]: undefined flexable length integer offset values used in [[DECLARE LIBRARY]] declarations.




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<center>[[#toc|Return to Top]]</center>
<center>[[#toc|Return to Top]]</center>


==Mathematical Operation Symbols==
 
== Mathematical Operation Symbols ==
Most of the BASIC math operators are ones that require no introduction. The addition, subtraction, multplication and division operators are ones commonly used as shown below:
Most of the BASIC math operators are ones that require no introduction. The addition, subtraction, multplication and division operators are ones commonly used as shown below:


{| align="center" border=1  
{| align="center" border=1
! Symbol  
! Symbol
! Procedure Type
! Procedure Type
! Example Usage
! Example Usage
! Operation Order  
! Operation Order
|-  
|-
| align="center" |[[+]] ||  Addition || align="center" | c = a + b  || align="center" | Last
| align="center" |[[+]] ||  Addition || align="center" | c = a + b  || align="center" | Last
|-
|-
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|-
|-
| align="center" |[[-]] ||  Negation  || align="center" | c = - a || align="center" | Last
| align="center" |[[-]] ||  Negation  || align="center" | c = - a || align="center" | Last
|-  
|-
| align="center" |[[*]] ||  Multiplication || align="center" | c = a * b || align="center" | Second
| align="center" |[[*]] ||  Multiplication || align="center" | c = a * b || align="center" | Second
|-
|-
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!Procedure Type
!Procedure Type
!Example Usage
!Example Usage
!Operation Order  
!Operation Order
|-
|-
| align="center" |[[\]] ||  Integer division || align="center" | c = a \ b || align="center" | Second  
| align="center" |[[\]] ||  Integer division || align="center" | c = a \ b || align="center" | Second
|-
|-
| align="center" |[[MOD]] ||  Remainder division  || align="center" | c = a MOD b || align="center" | Second
| align="center" |[[MOD]] ||  Remainder division  || align="center" | c = a MOD b || align="center" | Second
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There is also an operator for '''exponential''' calculations. The exponential operator is used to raise a number's value to a designated exponent of itself. In QB the exponential return values are [[DOUBLE]] values. The [[SQR]] function can return a number's Square Root. For other '''exponential roots''' the operator can be used with fractions such as (1 / 3) designating the cube root of a number.  
There is also an operator for '''exponential''' calculations. The exponential operator is used to raise a number's value to a designated exponent of itself. In QB the exponential return values are [[DOUBLE]] values. The [[SQR]] function can return a number's Square Root. For other '''exponential roots''' the operator can be used with fractions such as (1 / 3) designating the cube root of a number.




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!Symbol
!Symbol
!Procedure
!Procedure
!Example Usage  
!Example Usage
!Operation Order
!Operation Order
|-
|-
| align="center" |[[^]] || Exponent || align="center" | c = a [[^]] (1 / 2) || align="center" | First
| align="center" |[[^]] || Exponent || align="center" | c = a [[^]] (1 / 2) || align="center" | First
|-
|-
| align="center" | [[SQR]] || Square Root || align="center" | c = [[SQR]](a [[^]] 2 + b [[^]] 2) || align="center" | First  
| align="center" | [[SQR]] || Square Root || align="center" | c = [[SQR]](a [[^]] 2 + b [[^]] 2) || align="center" | First
|}
|}


 
=== Notes ===
===Notes===
* Exponent fractions should be enclosed in () brackets in order to be treated as a root rather than as division.
* Exponent fractions should be enclosed in () brackets in order to be treated as a root rather than as division.
* Negative exponential values must be enclosed in () brackets in QB64.
* Negative exponential values must be enclosed in () brackets in QB64.
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<center>[[#toc|Return to Top]]</center>
<center>[[#toc|Return to Top]]</center>


==Basic's Order of Operations==
 
== Basic's Order of Operations ==


When a normal calculation is made, BASIC works from left to right, but it does certain calculations in the following order:
When a normal calculation is made, BASIC works from left to right, but it does certain calculations in the following order:
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Sometimes a calculation may need BASIC to do them in another order or the calculation will return bad results. BASIC allows the programmer to decide the order of operations by using [[parenthesis]] around parts of the equation. BASIC will do the calculations inside of the [[parenthesis]] brackets  first and the others from left to right in the normal operation order.
Sometimes a calculation may need BASIC to do them in another order or the calculation will return bad results. BASIC allows the programmer to decide the order of operations by using [[parenthesis]] around parts of the equation. BASIC will do the calculations inside of the [[parenthesis]] brackets  first and the others from left to right in the normal operation order.


==Basic's Mathematical Functions==
 
== Basic's Mathematical Functions ==


{| align=center border=1
{| align=center border=1
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  |-
  |-
  | [[ABS]](n) || returns the absolute (positive) value of n: ABS(-5) = 5
  | [[ABS]](n) || returns the absolute (positive) value of n: ABS(-5) = 5
  |-  
  |-
  | [[ATN]](angle*) || returns the arctangent of an angle in radians: π = 4 * ATN(1)
  | [[ATN]](angle*) || returns the arctangent of an angle in radians: π = 4 * ATN(1)
  |-
  |-
  | [[COS]](angle*) || returns the cosine of an angle in radians. (horizontal component)
  | [[COS]](angle*) || returns the cosine of an angle in radians. (horizontal component)
  |-
  |-
  | [[EXP]](n) || returns e<sup>x</sup>, '''(n <= 88.02969)''': e = EXP(1) ' (e = 2.718281828459045)
  | [[EXP]](n) || returns e ^ x, '''(n <= 88.02969)''': e = EXP(1) ' (e = 2.718281828459045)
  |-
  |-
  | [[LOG]](n) || returns the base e natural logarithm of n. '''(n > 0)'''
  | [[LOG]](n) || returns the base e natural logarithm of n. '''(n > 0)'''
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                                     '''Logarithm to base n'''
                                     '''Logarithm to base n'''
FUNCTION LOGN (X, n)  
FUNCTION LOGN (X, n)
IF n > 0 AND n <> 1 AND X > 0 THEN LOGN = {{Cb|LOG}}(X) / {{Cb|LOG}}(n) ELSE BEEP
IF n > 0 AND n <> 1 AND X > 0 THEN LOGN = {{Cb|LOG}}(X) / {{Cb|LOG}}(n) ELSE BEEP
END FUNCTION
END FUNCTION
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FUNCTION LOG10 (X)    'base 10 logarithm
FUNCTION LOG10 (X)    'base 10 logarithm
IF X > 0 THEN LOG10 = {{Cb|LOG}}(X) / {{Cb|LOG}}(10) ELSE BEEP
IF X > 0 THEN LOG10 = {{Cb|LOG}}(X) / {{Cb|LOG}}(10) ELSE BEEP
END FUNCTION '' ''
END FUNCTION
{{TextEnd}}
{{TextEnd}}


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<center>[[#toc|Return to Top]]</center>
<center>[[#toc|Return to Top]]</center>


==Derived Mathematical Functions==


== Derived Mathematical Functions ==


The following Trigonometric functions can be derived from the '''BASIC Mathematical Functions''' listed above. Each function checks that certain values can be used without error or a [[BEEP]] will notify the user that a value could not be returned. An error handling routine can be substituted if desired. '''Note:''' Functions requiring '''π''' use 4 * [[ATN]](1) for [[SINGLE]] accuracy. Use [[ATN]](1.#) for [[DOUBLE]] accuracy.
The following Trigonometric functions can be derived from the '''BASIC Mathematical Functions''' listed above. Each function checks that certain values can be used without error or a [[BEEP]] will notify the user that a value could not be returned. An error handling routine can be substituted if desired. '''Note:''' Functions requiring '''π''' use 4 * [[ATN]](1) for [[SINGLE]] accuracy. Use [[ATN]](1.#) for [[DOUBLE]] accuracy.


{{CodeStart}}
{{Cl|FUNCTION}} {{Text|SEC|#55FF55}} (x) {{Text|<nowiki>'Secant</nowiki>|#919191}}
    {{Cl|IF}} {{Cl|COS}}(x) <> {{Text|0|#F580B1}} {{Cl|THEN}} {{Text|SEC|#55FF55}} = {{Text|1|#F580B1}} / {{Cl|COS}}(x) {{Cl|ELSE}} {{Cl|BEEP}}
{{Cl|END FUNCTION}}


{{TextStart}}'' ''
{{Cl|FUNCTION}} {{Text|CSC|#55FF55}} (x) {{Text|<nowiki>'CoSecant</nowiki>|#919191}}
FUNCTION SEC (x) 'Secant
    {{Cl|IF}} {{Cl|SIN}}(x) <> {{Text|0|#F580B1}} {{Cl|THEN}} {{Text|CSC|#55FF55}} = {{Text|1|#F580B1}} / {{Cl|SIN}}(x) {{Cl|ELSE}} {{Cl|BEEP}}
IF COS(x) <> 0 THEN SEC = 1 / {{Cb|COS}}(x) ELSE BEEP
{{Cl|END FUNCTION}}
END FUNCTION


FUNCTION CSC (x) 'CoSecant
{{Cl|FUNCTION}} {{Text|COT|#55FF55}} (x) {{Text|<nowiki>'CoTangent</nowiki>|#919191}}
IF SIN(x) <> 0 THEN CSC = 1 / {{Cb|SIN}}(x) ELSE BEEP
    {{Cl|IF}} {{Cl|TAN}}(x) <> {{Text|0|#F580B1}} {{Cl|THEN}} {{Text|COT|#55FF55}} = {{Text|1|#F580B1}} / {{Cl|TAN}}(x) {{Cl|ELSE}} {{Cl|BEEP}}
END FUNCTION  
{{Cl|END FUNCTION}}


FUNCTION COT (x) 'CoTangent
{{Cl|FUNCTION}} {{Text|ARCSIN|#55FF55}} (x) {{Text|<nowiki>'Inverse Sine</nowiki>|#919191}}
IF TAN(x) <> 0 THEN COT = 1 / {{Cb|TAN}}(x) ELSE BEEP
    {{Cl|IF}} x < {{Text|1|#F580B1}} {{Cl|THEN}} {{Text|ARCSIN|#55FF55}} = {{Cl|ATN}}(x / {{Cl|SQR}}({{Text|1|#F580B1}} - (x * x))) {{Cl|ELSE}} {{Cl|BEEP}}
END FUNCTION  
{{Cl|END FUNCTION}}


FUNCTION ARCSIN (x)   'Inverse Sine         
{{Cl|FUNCTION}} {{Text|ARCCOS|#55FF55}} (x) {{Text|<nowiki>' Inverse Cosine</nowiki>|#919191}}
IF x < 1 THEN ARCSIN = {{Cb|ATN}}(x / {{Cb|SQR}}(1 - (x * x))) ELSE BEEP
    {{Cl|IF}} x < {{Text|1|#F580B1}} {{Cl|THEN}} {{Text|ARCCOS|#55FF55}} = ({{Text|2|#F580B1}} * {{Cl|ATN}}({{Text|1|#F580B1}})) - {{Cl|ATN}}(x / {{Cl|SQR}}({{Text|1|#F580B1}} - x * x)) {{Cl|ELSE}} {{Cl|BEEP}}
END FUNCTION  
{{Cl|END FUNCTION}}


FUNCTION ARCCOS (x) ' Inverse Cosine
{{Cl|FUNCTION}} {{Text|ARCSEC|#55FF55}} (x) {{Text|<nowiki>' Inverse Secant</nowiki>|#919191}}
IF x < 1 THEN ARCCOS = (2 * ATN(1)) - {{Cb|ATN}}(x / {{Cb|SQR}}(1 - x * x)) ELSE BEEP
    {{Cl|IF}} x < {{Text|1|#F580B1}} {{Cl|THEN}} {{Text|ARCSEC|#55FF55}} = {{Cl|ATN}}(x / {{Cl|SQR}}({{Text|1|#F580B1}} - x * x)) + ({{Cl|SGN}}(x) - {{Text|1|#F580B1}}) * ({{Text|2|#F580B1}} * {{Cl|ATN}}({{Text|1|#F580B1}})) {{Cl|ELSE}} {{Cl|BEEP}}
END FUNCTION
{{Cl|END FUNCTION}}


FUNCTION ARCSEC (x)   ' Inverse Secant       
{{Cl|FUNCTION}} {{Text|ARCCSC|#55FF55}} (x) {{Text|<nowiki>' Inverse CoSecant</nowiki>|#919191}}
IF x < 1 THEN ARCSEC = {{Cb|ATN}}(x / {{Cb|SQR}}(1 - x * x)) + ({{Cb|SGN}}(x) - 1) * (2 * ATN(1)) ELSE BEEP
    {{Cl|IF}} x < {{Text|1|#F580B1}} {{Cl|THEN}} {{Text|ARCCSC|#55FF55}} = {{Cl|ATN}}({{Text|1|#F580B1}} / {{Cl|SQR}}({{Text|1|#F580B1}} - x * x)) + ({{Cl|SGN}}(x) - {{Text|1|#F580B1}}) * ({{Text|2|#F580B1}} * {{Cl|ATN}}({{Text|1|#F580B1}})) {{Cl|ELSE}} {{Cl|BEEP}}
END FUNCTION  
{{Cl|END FUNCTION}}


FUNCTION ARCCSC (x) ' Inverse CoSecant
{{Cl|FUNCTION}} {{Text|ARCCOT|#55FF55}} (x) {{Text|<nowiki>' Inverse CoTangent</nowiki>|#919191}}
IF x < 1 THEN ARCCSC = ATN(1 / SQR(1 - x * x)) + (SGN(x)-1) * (2 * ATN(1)) ELSE BEEP
    {{Text|ARCCOT|#55FF55}} = ({{Text|2|#F580B1}} * {{Cl|ATN}}({{Text|1|#F580B1}})) - {{Cl|ATN}}(x)
END FUNCTION  
{{Cl|END FUNCTION}}


FUNCTION ARCCOT (x) ' Inverse CoTangent
{{Cl|FUNCTION}} {{Text|SINH|#55FF55}} (x) {{Text|<nowiki>' Hyperbolic Sine</nowiki>|#919191}}
ARCCOT = (2 * {{Cb|ATN}}(1)) - {{Cb|ATN}}(x)
    {{Cl|IF}} x <= {{Text|88.02969|#F580B1}} {{Cl|THEN}} {{Text|SINH|#55FF55}} = ({{Cl|EXP}}(x) - {{Cl|EXP}}(-x)) / {{Text|2|#F580B1}} {{Cl|ELSE}} {{Cl|BEEP}}
END FUNCTION
{{Cl|END FUNCTION}}


FUNCTION SINH (x) ' Hyperbolic Sine
{{Cl|FUNCTION}} {{Text|COSH|#55FF55}} (x) {{Text|<nowiki>' Hyperbolic CoSine</nowiki>|#919191}}
IF x <= 88.02969 THEN SINH = ({{Cb|EXP}}(x) - {{Cb|EXP}}(-x)) / 2 ELSE BEEP
    {{Cl|IF}} x <= {{Text|88.02969|#F580B1}} {{Cl|THEN}} {{Text|COSH|#55FF55}} = ({{Cl|EXP}}(x) + {{Cl|EXP}}(-x)) / {{Text|2|#F580B1}} {{Cl|ELSE}} {{Cl|BEEP}}
END FUNCTION
{{Cl|END FUNCTION}}


FUNCTION COSH (x) ' Hyperbolic CoSine
{{Cl|FUNCTION}} {{Text|TANH|#55FF55}} (x) {{Text|<nowiki>' Hyperbolic Tangent or SINH(x) / COSH(x)</nowiki>|#919191}}
IF x <= 88.02969 THEN COSH = (EXP(x) + EXP(-x)) / 2 ELSE BEEP
    {{Cl|IF}} {{Text|2|#F580B1}} * x <= {{Text|88.02969|#F580B1}} {{Cl|AND (boolean)|AND}} {{Cl|EXP}}({{Text|2|#F580B1}} * x) + {{Text|1|#F580B1}} <> {{Text|0|#F580B1}} {{Cl|THEN}}
END FUNCTION
        {{Text|TANH|#55FF55}} = ({{Cl|EXP}}({{Text|2|#F580B1}} * x) - {{Text|1|#F580B1}}) / ({{Cl|EXP}}({{Text|2|#F580B1}} * x) + {{Text|1|#F580B1}})
    {{Cl|ELSE}} {{Cl|BEEP}}
    {{Cl|END IF}}
{{Cl|END FUNCTION}}


FUNCTION TANH (x) ' Hyperbolic Tangent or SINH(x) / COSH(x)
{{Cl|FUNCTION}} {{Text|SECH|#55FF55}} (x) {{Text|<nowiki>' Hyperbolic Secant or (COSH(x)) ^ -1</nowiki>|#919191}}
IF 2 * x <= 88.02969 AND EXP(2 * x) + 1 <> 0 THEN  
    {{Cl|IF}} x <= {{Text|88.02969|#F580B1}} {{Cl|AND (boolean)|AND}} ({{Cl|EXP}}(x) + {{Cl|EXP}}(-x)) <> {{Text|0|#F580B1}} {{Cl|THEN}} {{Text|SECH|#55FF55}} = {{Text|2|#F580B1}} / ({{Cl|EXP}}(x) + {{Cl|EXP}}(-x)) {{Cl|ELSE}} {{Cl|BEEP}}
    TANH = ({{Cb|EXP}}(2 * x) - 1) / ({{Cb|EXP}}(2 * x) + 1)  
{{Cl|END FUNCTION}}
ELSE BEEP  
END IF
END FUNCTION


FUNCTION SECH (x) ' Hyperbolic Secant or (COSH(x)) ^ -1
{{Cl|FUNCTION}} {{Text|CSCH|#55FF55}} (x) {{Text|<nowiki>' Hyperbolic CoSecant or (SINH(x)) ^ -1</nowiki>|#919191}}
IF x <= 88.02969 AND (EXP(x) + EXP(-x)) <> 0 THEN SECH = 2 / ({{Cb|EXP}}(x) + {{Cb|EXP}}(-x)) ELSE BEEP
    {{Cl|IF}} x <= {{Text|88.02969|#F580B1}} {{Cl|AND (boolean)|AND}} ({{Cl|EXP}}(x) - {{Cl|EXP}}(-x)) <> {{Text|0|#F580B1}} {{Cl|THEN}} {{Text|CSCH|#55FF55}} = {{Text|2|#F580B1}} / ({{Cl|EXP}}(x) - {{Cl|EXP}}(-x)) {{Cl|ELSE}} {{Cl|BEEP}}
END FUNCTION
{{Cl|END FUNCTION}}


FUNCTION CSCH (x) ' Hyperbolic CoSecant or (SINH(x)) ^ -1
{{Cl|FUNCTION}} {{Text|COTH|#55FF55}} (x) {{Text|<nowiki>' Hyperbolic CoTangent or COSH(x) / SINH(x)</nowiki>|#919191}}
IF x <= 88.02969 AND (EXP(x) - EXP(-x)) <> 0 THEN CSCH = 2 / ({{Cb|EXP}}(x) - {{Cb|EXP}}(-x)) ELSE BEEP
    {{Cl|IF}} {{Text|2|#F580B1}} * x <= {{Text|88.02969|#F580B1}} {{Cl|AND (boolean)|AND}} {{Cl|EXP}}({{Text|2|#F580B1}} * x) - {{Text|1|#F580B1}} <> {{Text|0|#F580B1}} {{Cl|THEN}}
END FUNCTION
        {{Text|COTH|#55FF55}} = ({{Cl|EXP}}({{Text|2|#F580B1}} * x) + {{Text|1|#F580B1}}) / ({{Cl|EXP}}({{Text|2|#F580B1}} * x) - {{Text|1|#F580B1}})
    {{Cl|ELSE}} {{Cl|BEEP}}
    {{Cl|END IF}}
{{Cl|END FUNCTION}}


FUNCTION COTH (x) ' Hyperbolic CoTangent or COSH(x) / SINH(x)
{{Cl|FUNCTION}} {{Text|ARCSINH|#55FF55}} (x) {{Text|<nowiki>' Inverse Hyperbolic Sine</nowiki>|#919191}}
IF 2 * x <= 88.02969 AND EXP(2 * x) - 1 <> 0 THEN  
    {{Cl|IF}} (x * x) + {{Text|1|#F580B1}} >= {{Text|0|#F580B1}} {{Cl|AND (boolean)|AND}} x + {{Cl|SQR}}((x * x) + {{Text|1|#F580B1}}) > {{Text|0|#F580B1}} {{Cl|THEN}}
    COTH = ({{Cb|EXP}}(2 * x) + 1) / ({{Cb|EXP}}(2 * x) - 1)  
        {{Text|ARCSINH|#55FF55}} = {{Cl|LOG}}(x + {{Cl|SQR}}(x * x + {{Text|1|#F580B1}}))
ELSE BEEP
    {{Cl|ELSE}} {{Cl|BEEP}}
END IF
    {{Cl|END IF}}
END FUNCTION
{{Cl|END FUNCTION}}


FUNCTION ARCSINH (x) ' Inverse Hyperbolic Sine
{{Cl|FUNCTION}} {{Text|ARCCOSH|#55FF55}} (x) {{Text|<nowiki>' Inverse Hyperbolic CoSine</nowiki>|#919191}}
IF (x * x) + 1 >= 0 AND x + SQR((x * x) + 1) > 0 THEN  
    {{Cl|IF}} x >= {{Text|1|#F580B1}} {{Cl|AND (boolean)|AND}} x * x - {{Text|1|#F580B1}} >= {{Text|0|#F580B1}} {{Cl|AND (boolean)|AND}} x + {{Cl|SQR}}(x * x - {{Text|1|#F580B1}}) > {{Text|0|#F580B1}} {{Cl|THEN}}
ARCSINH = {{Cb|LOG}}(x + {{Cb|SQR}}(x * x + 1))  
        {{Text|ARCCOSH|#55FF55}} = {{Cl|LOG}}(x + {{Cl|SQR}}(x * x - {{Text|1|#F580B1}}))
ELSE BEEP
    {{Cl|ELSE}} {{Cl|BEEP}}
END IF
    {{Cl|END IF}}
END FUNCTION
{{Cl|END FUNCTION}}


FUNCTION ARCCOSH (x) ' Inverse Hyperbolic CoSine
{{Cl|FUNCTION}} {{Text|ARCTANH|#55FF55}} (x) {{Text|<nowiki>' Inverse Hyperbolic Tangent</nowiki>|#919191}}
IF x >= 1 AND x * x - 1 >= 0 AND x + SQR(x * x - 1) > 0 THEN  
    {{Cl|IF}} x < {{Text|1|#F580B1}} {{Cl|THEN}} {{Text|ARCTANH|#55FF55}} = {{Cl|LOG}}(({{Text|1|#F580B1}} + x) / ({{Text|1|#F580B1}} - x)) / {{Text|2|#F580B1}} {{Cl|ELSE}} {{Cl|BEEP}}
ARCCOSH = {{Cb|LOG}}(x + {{Cb|SQR}}(x * x - 1))  
{{Cl|END FUNCTION}}
ELSE BEEP
END IF
END FUNCTION


FUNCTION ARCTANH (x) ' Inverse Hyperbolic Tangent
{{Cl|FUNCTION}} {{Text|ARCSECH|#55FF55}} (x) {{Text|<nowiki>' Inverse Hyperbolic Secant</nowiki>|#919191}}
IF x < 1 THEN ARCTANH = {{Cb|LOG}}((1 + x) / (1 - x)) / 2 ELSE BEEP
    {{Cl|IF}} x > {{Text|0|#F580B1}} {{Cl|AND (boolean)|AND}} x <= {{Text|1|#F580B1}} {{Cl|THEN}} {{Text|ARCSECH|#55FF55}} = {{Cl|LOG}}(({{Cl|SGN}}(x) * {{Cl|SQR}}({{Text|1|#F580B1}} - x * x) + {{Text|1|#F580B1}}) / x) {{Cl|ELSE}} {{Cl|BEEP}}
END FUNCTION  
{{Cl|END FUNCTION}}


FUNCTION ARCSECH (x) ' Inverse Hyperbolic Secant
{{Cl|FUNCTION}} {{Text|ARCCSCH|#55FF55}} (x) {{Text|<nowiki>' Inverse Hyperbolic CoSecant</nowiki>|#919191}}
IF x > 0 AND x <= 1 THEN ARCSECH = {{Cb|LOG}}(({{Cb|SGN}}(x) * {{Cb|SQR}}(1 - x * x) + 1) / x) ELSE BEEP
    {{Cl|IF}} x <> {{Text|0|#F580B1}} {{Cl|AND (boolean)|AND}} x * x + {{Text|1|#F580B1}} >= {{Text|0|#F580B1}} {{Cl|AND (boolean)|AND}} ({{Cl|SGN}}(x) * {{Cl|SQR}}(x * x + {{Text|1|#F580B1}}) + {{Text|1|#F580B1}}) / x > {{Text|0|#F580B1}} {{Cl|THEN}}
END FUNCTION
        {{Text|ARCCSCH|#55FF55}} = {{Cl|LOG}}(({{Cl|SGN}}(x) * {{Cl|SQR}}(x * x + {{Text|1|#F580B1}}) + {{Text|1|#F580B1}}) / x)
    {{Cl|ELSE}} {{Cl|BEEP}}
    {{Cl|END IF}}
{{Cl|END FUNCTION}}


FUNCTION ARCCSCH (x) ' Inverse Hyperbolic CoSecant
{{Cl|FUNCTION}} {{Text|ARCCOTH|#55FF55}} (x) {{Text|<nowiki>' Inverse Hyperbolic CoTangent</nowiki>|#919191}}
IF x <> 0 AND x * x + 1 >= 0 AND (SGN(x) * SQR(x * x + 1) + 1) / x > 0 THEN
    {{Cl|IF}} x > {{Text|1|#F580B1}} {{Cl|THEN}} {{Text|ARCCOTH|#55FF55}} = {{Cl|LOG}}((x + {{Text|1|#F580B1}}) / (x - {{Text|1|#F580B1}})) / {{Text|2|#F580B1}} {{Cl|ELSE}} {{Cl|BEEP}}
    ARCCSCH = {{Cb|LOG}}(({{Cb|SGN}}(x) * {{Cb|SQR}}(x * x + 1) + 1) / x)
{{Cl|END FUNCTION}}
ELSE BEEP
{{CodeEnd}}
END IF
{{FixedStart}}
END FUNCTION
 
FUNCTION ARCCOTH (x)  ' Inverse Hyperbolic CoTangent
IF x > 1 THEN ARCCOTH = {{Cb|LOG}}((x + 1) / (x - 1)) / 2 ELSE BEEP
END FUNCTION '' ''
{{TextEnd}}
{{WhiteStart}}
                           '''Hyperbolic Function Relationships:'''
                           '''Hyperbolic Function Relationships:'''


                                   COSH(-x) = COSH(x)
                                   COSH(-x) = COSH(x)
                                   SINH(-x) = -SINH(x)
                                   SINH(-x) = -SINH(x)
                                   
 
                                   SECH(-x) = SECH(x)
                                   SECH(-x) = SECH(x)
                                   CSCH(-x) = -CSCH(x)
                                   CSCH(-x) = -CSCH(x)
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                       '''Inverse Hyperbolic Function Relatonships:'''
                       '''Inverse Hyperbolic Function Relatonships:'''


                               ARSECH(x) = ARCOSH(x) ^ -1  
                               ARSECH(x) = ARCOSH(x) ^ -1
                               ARCSCH(x) = ARSINH(x) ^ -1  
                               ARCSCH(x) = ARSINH(x) ^ -1
                               ARCOTH(x) = ARTANH(x) ^ -1  
                               ARCOTH(x) = ARTANH(x) ^ -1


               '''Hyperbolic sine and cosine satisfy the Pythagorean trig. identity:'''
               '''Hyperbolic sine and cosine satisfy the Pythagorean trig. identity:'''
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                           (COSH(x) ^ 2) - (SINH(x) ^ 2) = 1
                           (COSH(x) ^ 2) - (SINH(x) ^ 2) = 1


{{WhiteEnd}}
{{FixedEnd}}


<center>[http://support.microsoft.com/kb/28249 Microsoft's Derived BASIC Functions (KB 28249)]</center>
<center>[http://support.microsoft.com/kb/28249 Microsoft's Derived BASIC Functions (KB 28249)]</center>
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<center>[[#toc|Return to Top]]</center>
<center>[[#toc|Return to Top]]</center>


==Mathematical Logical Operators==
 
== Mathematical Logical Operators ==


The following logical operators compare numerical values using bitwise operations. The two numbers are compared by the number's [[Binary]] bits on and the result of the operation determines the value returned in decimal form. [[NOT]] checks one value and returns the opposite. It returns 0 if a value is not 0 and -1 if it is 0. See [[Binary]] for more on bitwise operations.
The following logical operators compare numerical values using bitwise operations. The two numbers are compared by the number's [[Binary]] bits on and the result of the operation determines the value returned in decimal form. [[NOT]] checks one value and returns the opposite. It returns 0 if a value is not 0 and -1 if it is 0. See [[Binary]] for more on bitwise operations.
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<center>[[#toc|Return to Top]]</center>
<center>[[#toc|Return to Top]]</center>


==Relational Operations==
 
== Relational Operations ==
Relational Operations are used to compare values in a Conditional [[IF...THEN]], [[SELECT CASE]], [[UNTIL]] or [[WHILE]] statement.
Relational Operations are used to compare values in a Conditional [[IF...THEN]], [[SELECT CASE]], [[UNTIL]] or [[WHILE]] statement.
{{RelationalOperationsPlugin}}
{{RelationalOperationsPlugin}}
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<center>[[#toc|Return to Top]]</center>
<center>[[#toc|Return to Top]]</center>


==Basic's Rounding Functions==
 
== Basic's Rounding Functions ==


: Rounding is used when the program needs a certain number value or type. There are 4 [[INTEGER]] or [[LONG]] Integer functions and one function each for closest [[SINGLE]] and closest [[DOUBLE]] numerical types. Closest functions use "bankers" rounding which rounds up if the decimal point value is over one half. Variable types should match the return value.
: Rounding is used when the program needs a certain number value or type. There are 4 [[INTEGER]] or [[LONG]] Integer functions and one function each for closest [[SINGLE]] and closest [[DOUBLE]] numerical types. Closest functions use "bankers" rounding which rounds up if the decimal point value is over one half. Variable types should match the return value.
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|}
|}


===Note===
=== Notes ===
* Each of the above functions define the value's type in addition to rounding the values.
* Each of the above functions define the value's type in addition to rounding the values.


<center>[[#toc|Return to Top]]</center>
<center>[[#toc|Return to Top]]</center>


==Base Number Systems==
 
== Base Number Systems ==




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   '''Decimal (base 10)    Binary (base 2)    Hexadecimal (base 16)    Octal (base 8)'''
   '''Decimal (base 10)    Binary (base 2)    Hexadecimal (base 16)    Octal (base 8)'''


                           '''  [[&B]]                [[&H]] [[HEX$]](n)          [[&O]] [[OCT$]](n)'''    
                           '''  [[&B]]                [[&H]] [[HEX$]](n)          [[&O]] [[OCT$]](n)'''


           0                  0000                  0                    0
           0                  0000                  0                    0
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         15  -------------  1111 <--- Match --->  F  ----------------  17 -- max 2
         15  -------------  1111 <--- Match --->  F  ----------------  17 -- max 2
         16                10000                10                    20
         16                10000                10                    20
       
 
       When the Decimal value is 15, the other 2 base systems are all maxed out!
       When the Decimal value is 15, the other 2 base systems are all maxed out!
       The Binary values can be compared to all of the HEX value digit values so
       The Binary values can be compared to all of the HEX value digit values so
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       value to Binary just add the 4 binary digits for each HEX digit place so:
       value to Binary just add the 4 binary digits for each HEX digit place so:


                         F      A      C      E  
                         F      A      C      E
               &HFACE = 1111 + 1010 + 1100 + 1101 = &B1111101011001101
               &HFACE = 1111 + 1010 + 1100 + 1101 = &B1111101011001101


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       sections of four digits starting from the right(LSB) end. If one has less
       sections of four digits starting from the right(LSB) end. If one has less
       than 4 digits on the left end you could add the leading zeros like below:
       than 4 digits on the left end you could add the leading zeros like below:
 
             &B101011100010001001 = 0010 1011 1000 1000 1001
             &B101011100010001001 = 0010 1011 1000 1000 1001
                       hexadecimal =  2  + B  + 8 +  8  + 9 = &H2B889  
                       hexadecimal =  2  + B  + 8 +  8  + 9 = &H2B889


     See the Decimal to Binary conversion function that uses '''[[HEX$]]''' on the '''[[&H]]''' page.
     See the Decimal to Binary conversion function that uses '''[[HEX$]]''' on the '''[[&H]]''' page.
 
{{TextEnd}}
{{TextEnd}}


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<center>[[#toc|Return to Top]]</center>
<center>[[#toc|Return to Top]]</center>


==Bits and Bytes==
 
== Bits and Bytes ==


<center>'''[[_BIT|BITS]]'''</center>
<center>'''[[_BIT|BITS]]'''</center>
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:* '''"Big-endian"''': MSB is the first bit encountered, decreasing to the LSB as the last bit by position, memory address or time.
:* '''"Big-endian"''': MSB is the first bit encountered, decreasing to the LSB as the last bit by position, memory address or time.
:* '''"Little-endian"''': LSB is the first bit encountered, increasing to the MSB as the last bit by position, memory address or time.
:* '''"Little-endian"''': LSB is the first bit encountered, increasing to the MSB as the last bit by position, memory address or time.
{{WhiteStart}}
{{FixedStart}}
         '''Offset or Position:    0    1  2  3  4  5  6  7      Example: 11110000'''
         '''Offset or Position:    0    1  2  3  4  5  6  7      Example: 11110000'''
                               ----------------------------------            --------
                               ----------------------------------            --------
     '''Big-Endian Bit On Value:'''  128  64  32  16  8  4  2  1                240
     '''Big-Endian Bit On Value:'''  128  64  32  16  8  4  2  1                240
  '''Little-Endian Bit On Value:'''    1    2  4  8  16  32  64  128                15
  '''Little-Endian Bit On Value:'''    1    2  4  8  16  32  64  128                15
{{WhiteEnd}}
{{FixedEnd}}
::The big-endian method compares exponents of 2<sup>7</sup> down to 2<sup>0</sup> while the little-endian method does the opposite.  
::The big-endian method compares exponents of 2 ^ 7 down to 2 ^ 0 while the little-endian method does the opposite.


<center>'''[[_BYTE|BYTES]]'''</center>
<center>'''[[_BYTE|BYTES]]'''</center>
* [[INTEGER]] values consist of 2 bytes called the '''HI''' and '''LO''' bytes. Anytime that the number of binary digits is a multiple of 16 (2bytes, 4 bytes, etc.) and the HI byte's MSB is on(1), the value returned will be negative, even with [[SINGLE]] or [[DOUBLE]] values.  
* [[INTEGER]] values consist of 2 bytes called the '''HI''' and '''LO''' bytes. Anytime that the number of binary digits is a multiple of 16 (2bytes, 4 bytes, etc.) and the HI byte's MSB is on(1), the value returned will be negative, even with [[SINGLE]] or [[DOUBLE]] values.
{{WhiteStart}}                                '''16 BIT INTEGER OR REGISTER'''
{{FixedStart}}                                '''16 BIT INTEGER OR REGISTER'''
               '''AH (High Byte Bits)                        AL (Low Byte Bits)'''
               '''AH (High Byte Bits)                        AL (Low Byte Bits)'''
   BIT:    15    14  13  12  11  10  9  8  |  7  6    5  4    3    2  1    0
   BIT:    15    14  13  12  11  10  9  8  |  7  6    5  4    3    2  1    0
           ---------------------------------------|--------------------------------------
           ---------------------------------------|--------------------------------------
   HEX:  8000  4000 2000 1000  800 400  200 100 |  80  40  20  10  8    4  2    1
   HEX:  8000  4000 2000 1000  800 400  200 100 |  80  40  20  10  8    4  2    1
                                                 &verbar;
                                                 |
   DEC: -32768 16384 8192 4096 2048 1024 512 256 | 128  64  32  16  8    4  2    1
   DEC: -32768 16384 8192 4096 2048 1024 512 256 | 128  64  32  16  8    4  2    1
{{WhiteEnd}}
{{FixedEnd}}
::The HI byte's '''MSB''' is often called the '''sign''' bit! When the highest bit is on, the signed value returned will be negative.
::The HI byte's '''MSB''' is often called the '''sign''' bit! When the highest bit is on, the signed value returned will be negative.




''Example:'' Program displays the bits on for any integer value between -32768 and 32767 or &H80000 and &H7FFF.
''Example:'' Program displays the bits on for any integer value between -32768 and 32767 or &H80000 and &H7FFF.
{{CodeStart}} '' ''
{{CodeStart}}
{{Cl|DEFINT}} A-Z
{{Cl|DEFINT}} A-Z
{{Cl|SCREEN (statement)|SCREEN}} 12
{{Cl|SCREEN}} 12
{{Cl|COLOR}} 11: {{Cl|LOCATE}} 10, 2
{{Cl|COLOR}} 11: {{Cl|LOCATE}} 10, 2
  {{Cl|PRINT}} "      AH (High Register Byte Bits)          AL (Low Register Byte Bits)"
  {{Cl|PRINT}} "      AH (High Register Byte Bits)          AL (Low Register Byte Bits)"
Line 463: Line 469:
       {{Cl|IF}} (Num {{Cl|AND}} 2 ^ i) {{Cl|THEN}}
       {{Cl|IF}} (Num {{Cl|AND}} 2 ^ i) {{Cl|THEN}}
         {{Cl|PAINT}} (640 - (37 * (i + 1)), 189), 12, 9
         {{Cl|PAINT}} (640 - (37 * (i + 1)), 189), 12, 9
         Bin$ = Bin$ + "1"
         BinStr$ = BinStr$ + "1"
       {{Cl|ELSE}}
       {{Cl|ELSE}}
         {{Cl|PAINT}} (640 - (37 * (i + 1)), 189), 0, 9
         {{Cl|PAINT}} (640 - (37 * (i + 1)), 189), 0, 9
         Bin$ = Bin$ + "0"
         BinStr$ = BinStr$ + "0"
       {{Cl|END IF}}
       {{Cl|END IF}}
     {{Cl|NEXT}}
     {{Cl|NEXT}}
     {{Cl|COLOR}} 10: {{Cl|LOCATE}} 16, 50: {{Cl|PRINT}} "Binary ="; {{Cl|VAL}}(Bin$)
     {{Cl|COLOR}} 10: {{Cl|LOCATE}} 16, 50: {{Cl|PRINT}} "Binary ="; {{Cl|VAL}}(BinStr$)
     {{Cl|COLOR}} 9: {{Cl|LOCATE}} 16, 10: {{Cl|PRINT}} "Decimal ="; Num;: {{Cl|COLOR}} 13: {{Cl|PRINT}} "      Hex = "; Hexa$
     {{Cl|COLOR}} 9: {{Cl|LOCATE}} 16, 10: {{Cl|PRINT}} "Decimal ="; Num;: {{Cl|COLOR}} 13: {{Cl|PRINT}} "      Hex = "; Hexa$
     Hexa$ = "": Bin$ = ""
     Hexa$ = "": BinStr$ = ""
   {{Cl|END IF}}
   {{Cl|END IF}}
   {{Cl|COLOR}} 14: {{Cl|LOCATE}} 17, 15: {{Cl|INPUT}} "Enter a decimal or HEX({{Cl|&H}}) value (0 Quits): ", frst$
   {{Cl|COLOR}} 14: {{Cl|LOCATE}} 17, 15: {{Cl|INPUT}} "Enter a decimal or HEX({{Cl|&H}}) value (0 Quits): ", frst$
   first = {{Cl|VAL}}(frst$)
   first = {{Cl|VAL}}(frst$)
   {{Cl|IF}} first {{Cl|THEN}}
   {{Cl|IF}} first {{Cl|THEN}}
     {{Cl|LOCATE}} 17, 15: {{Cl|PRINT}} {{Cl|SPACE$}}(55)
     {{Cl|LOCATE}} 17, 15: {{Cl|PRINT}} {{Cl|SPACE$}}(55)
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{{Cl|COLOR}} 11: {{Cl|LOCATE}} 28, 30: {{Cl|PRINT}} "Press any key to exit!";
{{Cl|COLOR}} 11: {{Cl|LOCATE}} 28, 30: {{Cl|PRINT}} "Press any key to exit!";
{{Cl|SLEEP}}
{{Cl|SLEEP}}
{{Cl|SYSTEM}} '' ''
{{Cl|SYSTEM}}
{{CodeEnd}}
{{CodeEnd}}
{{small|Code by Ted Weissgerber}}
{{Small|Code by Ted Weissgerber}}




<center>[[#toc|Return to Top]]</center>
<center>[[#toc|Return to Top]]</center>


==OFFSET==
 
== OFFSET ==


* [[_OFFSET (function)]] returns the memory offset position as a flexible sized value for a designated variable. See [[Using _OFFSET]].
* [[_OFFSET (function)]] returns the memory offset position as a flexible sized value for a designated variable. See [[Using _OFFSET]].
Line 501: Line 508:




<center>'''[[_OFFSET]] values can only be used in conjunction with [[_MEM]]ory and [[DECLARE DYNAMIC LIBRARY]] procedures.'''</center>
<center>'''[[_OFFSET]] values can only be used in conjunction with [[_MEM]]ory and [[DECLARE LIBRARY]] procedures.'''</center>
 


==References==
{{PageSeeAlso}}
''See also:''
* [[_OFFSET]], [[_MEM]]
* [[_OFFSET]], [[_MEM]]
* [[DIM]], [[_DEFINE]]
* [[DIM]], [[_DEFINE]]
* [[TYPE]]
* [[TYPE]]


{{PageNavigation}}
 
{{PageReferences}}

Latest revision as of 13:58, 20 November 2024

Basic and QB64 Numerical Types

QBasic Number Types
  • INTEGER [%]: 2 Byte signed whole number values from -32768 to 32767. 0 to 65535 unsigned. (not checked in QB64)
  • LONG [&]: 4 byte signed whole number values from -2147483648 to 2147483647. 0 to 4294967295 unsigned.
  • SINGLE [!]: 4 byte signed floating decimal point values of up to 7 decimal place accuracy. Cannot be unsigned.
  • DOUBLE [#]: 8 byte signed floating decimal point values of up to 15 decimal place accuracy. Cannot be unsigned.
  • To get one byte values, can use an ASCII STRING character to represent values from 0 to 255 as in BINARY files.


QB64 Number Types
  • _BIT [`]: 1 bit signed whole number values of 0 or -1 signed or 0 or 1 unsigned. _BIT * 8 can hold a signed or unsigned byte value.
  • _BYTE [%%]: 1 byte signed whole number values from -128 to 127. Unsigned values from 0 to 255.
  • _INTEGER64 [&&]: 8 byte signed whole number values from -9223372036854775808 to 9223372036854775807
  • _FLOAT [##]: currently set as 10 byte signed floating decimal point values up to +/-1.189731495357231765F+4932. Cannot be unsigned.
  • _OFFSET [%&]: undefined flexable length integer offset values used in DECLARE LIBRARY declarations.


Signed and Unsigned Integer Values

Negative (signed) numerical values can affect calculations when using any of the BASIC operators. SQR cannot use negative values! There may be times that a calculation error is made using those negative values. The SGN function returns the sign of a value as -1 for negative, 0 for zero and 1 for unsigned positive values. ABS always returns an unsigned value.

  • SGN(n) returns the value's sign as -1 if negative, 0 if zero or 1 if positive.
  • ABS(n) changes negative values to the equivalent positive values.
  • QB64: _UNSIGNED in a DIM, AS or _DEFINE statement for only positive INTEGER values.


_UNSIGNED integer, byte and bit variable values can use the tilde ~ suffix before the type suffix to define the type.


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Mathematical Operation Symbols

Most of the BASIC math operators are ones that require no introduction. The addition, subtraction, multplication and division operators are ones commonly used as shown below:

Symbol Procedure Type Example Usage Operation Order
+ Addition c = a + b Last
- Subtraction c = a - b Last
- Negation c = - a Last
* Multiplication c = a * b Second
/ Division c = a / b Second


BASIC can also use two other operators for INTEGER division. Integer division returns only whole number values. MOD remainder division returns a value only if an integer division cannot divide a number exactly. Returns 0 if a value is exactly divisible.


Symbol Procedure Type Example Usage Operation Order
\ Integer division c = a \ b Second
MOD Remainder division c = a MOD b Second


It is an error to divide by zero or to take the remainder modulo zero.


There is also an operator for exponential calculations. The exponential operator is used to raise a number's value to a designated exponent of itself. In QB the exponential return values are DOUBLE values. The SQR function can return a number's Square Root. For other exponential roots the operator can be used with fractions such as (1 / 3) designating the cube root of a number.


Symbol Procedure Example Usage Operation Order
^ Exponent c = a ^ (1 / 2) First
SQR Square Root c = SQR(a ^ 2 + b ^ 2) First

Notes

  • Exponent fractions should be enclosed in () brackets in order to be treated as a root rather than as division.
  • Negative exponential values must be enclosed in () brackets in QB64.


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Basic's Order of Operations

When a normal calculation is made, BASIC works from left to right, but it does certain calculations in the following order:


  1. Exponential and exponential Root calculations including SQR.
  2. Negation (Note that this means that - 3 ^ 2 is treated as -(3 ^ 2) and not as (-3) ^ 2.)
  3. Multiplication, normal Division, INTEGER Division and Remainder(MOD) Division calculations
  4. Addition and Subtraction calculations


Using Parenthesis to Define the Operation Order

Sometimes a calculation may need BASIC to do them in another order or the calculation will return bad results. BASIC allows the programmer to decide the order of operations by using parenthesis around parts of the equation. BASIC will do the calculations inside of the parenthesis brackets first and the others from left to right in the normal operation order.


Basic's Mathematical Functions

Function Description
ABS(n) returns the absolute (positive) value of n: ABS(-5) = 5
ATN(angle*) returns the arctangent of an angle in radians: π = 4 * ATN(1)
COS(angle*) returns the cosine of an angle in radians. (horizontal component)
EXP(n) returns e ^ x, (n <= 88.02969): e = EXP(1) ' (e = 2.718281828459045)
LOG(n) returns the base e natural logarithm of n. (n > 0)
SGN(n) returns -1 if n < 0, 0 if n = 0, 1 if n > 0: SGN(-5) = -1
SIN(angle*) returns the sine of an angle in radians. (vertical component)
SQR(n) returns the square root of a number. (n >= 0)
TAN(angle*) returns the tangent of an angle in radians
* angles measured in radians


                                Degree to Radian Conversion:
FUNCTION Radian (degrees)
Radian = degrees * (4 * ATN(1)) / 180
END FUNCTION

FUNCTION Degree (radians)
Degree = radians * 180 / (4 * ATN(1))
END FUNCTION

                                    Logarithm to base n
FUNCTION LOGN (X, n)
IF n > 0 AND n <> 1 AND X > 0 THEN LOGN = LOG(X) / LOG(n) ELSE BEEP
END FUNCTION

FUNCTION LOG10 (X)    'base 10 logarithm
IF X > 0 THEN LOG10 = LOG(X) / LOG(10) ELSE BEEP
END FUNCTION


The numerical value of n in the LOG(n) evaluation must be a positive value.
The numerical value of n in the EXP(n) evaluation must be less than or equal to 88.02969.
The numerical value of n in the SQR(n) evaluation cannot be a negative value.


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Derived Mathematical Functions

The following Trigonometric functions can be derived from the BASIC Mathematical Functions listed above. Each function checks that certain values can be used without error or a BEEP will notify the user that a value could not be returned. An error handling routine can be substituted if desired. Note: Functions requiring π use 4 * ATN(1) for SINGLE accuracy. Use ATN(1.#) for DOUBLE accuracy.

FUNCTION SEC (x) 'Secant
    IF COS(x) <> 0 THEN SEC = 1 / COS(x) ELSE BEEP
END FUNCTION

FUNCTION CSC (x) 'CoSecant
    IF SIN(x) <> 0 THEN CSC = 1 / SIN(x) ELSE BEEP
END FUNCTION

FUNCTION COT (x) 'CoTangent
    IF TAN(x) <> 0 THEN COT = 1 / TAN(x) ELSE BEEP
END FUNCTION

FUNCTION ARCSIN (x) 'Inverse Sine
    IF x < 1 THEN ARCSIN = ATN(x / SQR(1 - (x * x))) ELSE BEEP
END FUNCTION

FUNCTION ARCCOS (x) ' Inverse Cosine
    IF x < 1 THEN ARCCOS = (2 * ATN(1)) - ATN(x / SQR(1 - x * x)) ELSE BEEP
END FUNCTION

FUNCTION ARCSEC (x) ' Inverse Secant
    IF x < 1 THEN ARCSEC = ATN(x / SQR(1 - x * x)) + (SGN(x) - 1) * (2 * ATN(1)) ELSE BEEP
END FUNCTION

FUNCTION ARCCSC (x) ' Inverse CoSecant
    IF x < 1 THEN ARCCSC = ATN(1 / SQR(1 - x * x)) + (SGN(x) - 1) * (2 * ATN(1)) ELSE BEEP
END FUNCTION

FUNCTION ARCCOT (x) ' Inverse CoTangent
    ARCCOT = (2 * ATN(1)) - ATN(x)
END FUNCTION

FUNCTION SINH (x) ' Hyperbolic Sine
    IF x <= 88.02969 THEN SINH = (EXP(x) - EXP(-x)) / 2 ELSE BEEP
END FUNCTION

FUNCTION COSH (x) ' Hyperbolic CoSine
    IF x <= 88.02969 THEN COSH = (EXP(x) + EXP(-x)) / 2 ELSE BEEP
END FUNCTION

FUNCTION TANH (x) ' Hyperbolic Tangent or SINH(x) / COSH(x)
    IF 2 * x <= 88.02969 AND EXP(2 * x) + 1 <> 0 THEN
        TANH = (EXP(2 * x) - 1) / (EXP(2 * x) + 1)
    ELSE BEEP
    END IF
END FUNCTION

FUNCTION SECH (x) ' Hyperbolic Secant or (COSH(x)) ^ -1
    IF x <= 88.02969 AND (EXP(x) + EXP(-x)) <> 0 THEN SECH = 2 / (EXP(x) + EXP(-x)) ELSE BEEP
END FUNCTION

FUNCTION CSCH (x) ' Hyperbolic CoSecant or (SINH(x)) ^ -1
    IF x <= 88.02969 AND (EXP(x) - EXP(-x)) <> 0 THEN CSCH = 2 / (EXP(x) - EXP(-x)) ELSE BEEP
END FUNCTION

FUNCTION COTH (x) ' Hyperbolic CoTangent or COSH(x) / SINH(x)
    IF 2 * x <= 88.02969 AND EXP(2 * x) - 1 <> 0 THEN
        COTH = (EXP(2 * x) + 1) / (EXP(2 * x) - 1)
    ELSE BEEP
    END IF
END FUNCTION

FUNCTION ARCSINH (x) ' Inverse Hyperbolic Sine
    IF (x * x) + 1 >= 0 AND x + SQR((x * x) + 1) > 0 THEN
        ARCSINH = LOG(x + SQR(x * x + 1))
    ELSE BEEP
    END IF
END FUNCTION

FUNCTION ARCCOSH (x) ' Inverse Hyperbolic CoSine
    IF x >= 1 AND x * x - 1 >= 0 AND x + SQR(x * x - 1) > 0 THEN
        ARCCOSH = LOG(x + SQR(x * x - 1))
    ELSE BEEP
    END IF
END FUNCTION

FUNCTION ARCTANH (x) ' Inverse Hyperbolic Tangent
    IF x < 1 THEN ARCTANH = LOG((1 + x) / (1 - x)) / 2 ELSE BEEP
END FUNCTION

FUNCTION ARCSECH (x) ' Inverse Hyperbolic Secant
    IF x > 0 AND x <= 1 THEN ARCSECH = LOG((SGN(x) * SQR(1 - x * x) + 1) / x) ELSE BEEP
END FUNCTION

FUNCTION ARCCSCH (x) ' Inverse Hyperbolic CoSecant
    IF x <> 0 AND x * x + 1 >= 0 AND (SGN(x) * SQR(x * x + 1) + 1) / x > 0 THEN
        ARCCSCH = LOG((SGN(x) * SQR(x * x + 1) + 1) / x)
    ELSE BEEP
    END IF
END FUNCTION

FUNCTION ARCCOTH (x) ' Inverse Hyperbolic CoTangent
    IF x > 1 THEN ARCCOTH = LOG((x + 1) / (x - 1)) / 2 ELSE BEEP
END FUNCTION
                           Hyperbolic Function Relationships:

                                   COSH(-x) = COSH(x)
                                   SINH(-x) = -SINH(x)

                                   SECH(-x) = SECH(x)
                                   CSCH(-x) = -CSCH(x)
                                   TANH(-x) = -TANH(x)
                                   COTH(-x) = -COTH(x)

                       Inverse Hyperbolic Function Relatonships:

                              ARSECH(x) = ARCOSH(x) ^ -1
                              ARCSCH(x) = ARSINH(x) ^ -1
                              ARCOTH(x) = ARTANH(x) ^ -1

              Hyperbolic sine and cosine satisfy the Pythagorean trig. identity:

                           (COSH(x) ^ 2) - (SINH(x) ^ 2) = 1

Microsoft's Derived BASIC Functions (KB 28249)


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Mathematical Logical Operators

The following logical operators compare numerical values using bitwise operations. The two numbers are compared by the number's Binary bits on and the result of the operation determines the value returned in decimal form. NOT checks one value and returns the opposite. It returns 0 if a value is not 0 and -1 if it is 0. See Binary for more on bitwise operations.


Truth table of the 6 BASIC Logical Operators


               Table 4: The logical operations and its results.

       In this table, A and B are the Expressions to invert or combine.
              Both may be results of former Boolean evaluations.
  ┌────────────────────────────────────────────────────────────────────────┐
  │                           Logical Operations                           │
  ├───────┬───────┬───────┬─────────┬────────┬─────────┬─────────┬─────────┤
  │   ABNOT BA AND BA OR BA XOR BA EQV BA IMP B │
  ├───────┼───────┼───────┼─────────┼────────┼─────────┼─────────┼─────────┤
  │ truetrue  │ false │  true   │ true   │  false  │  true   │  true   │
  ├───────┼───────┼───────┼─────────┼────────┼─────────┼─────────┼─────────┤
  │ truefalse │ true  │  false  │ true   │  true   │  false  │  false  │
  ├───────┼───────┼───────┼─────────┼────────┼─────────┼─────────┼─────────┤
  │ falsetrue  │ false │  false  │ true   │  true   │  false  │  true   │
  ├───────┼───────┼───────┼─────────┼────────┼─────────┼─────────┼─────────┤
  │ falsefalse │ true  │  false  │ false  │  false  │  true   │  true   │
  └───────┴───────┴───────┴─────────┴────────┴─────────┴─────────┴─────────┘
   Note: In most BASIC languages incl. QB64 these are bitwise operations,
         hence the logic is performed for each corresponding bit in both
         operators, where true or false indicates whether a bit is set or
         not set. The outcome of each bit is then placed into the respective
         position to build the bit pattern of the final result value.

   As all Relational Operations return negative one (-1, all bits set) for
    true and zero (0, no bits set) for false, this allows us to use these
    bitwise logical operations to invert or combine any relational checks,
    as the outcome is the same for each bit and so always results into a
            true (-1) or false (0) again for further evaluations.
BASIC can accept any + or - value that is not 0 to be True when used in an evaluation.


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Relational Operations

Relational Operations are used to compare values in a Conditional IF...THEN, SELECT CASE, UNTIL or WHILE statement.

         Table 3: The relational operations for condition checking.

 In this table, A and B are the Expressions to compare. Both must represent
 the same general type, i.e. they must result into either numerical values
 or STRING values. If a test succeeds, then true (-1) is returned, false (0)
     if it fails, which both can be used in further Boolean evaluations.
 ┌─────────────────────────────────────────────────────────────────────────┐
 │                          Relational Operations                          │
 ├────────────┬───────────────────────────────────────────┬────────────────┤
 │ OperationDescriptionExample usage  │
 ├────────────┼───────────────────────────────────────────┼────────────────┤
 │   A = B    │ Tests if A is equal to B.                 │ IF A = B THEN  │
 ├────────────┼───────────────────────────────────────────┼────────────────┤
 │   A <> B   │ Tests if A is not equal to B.             │ IF A <> B THEN │
 ├────────────┼───────────────────────────────────────────┼────────────────┤
 │   A < B    │ Tests if A is less than B.                │ IF A < B THEN  │
 ├────────────┼───────────────────────────────────────────┼────────────────┤
 │   A > B    │ Tests if A is greater than B.             │ IF A > B THEN  │
 ├────────────┼───────────────────────────────────────────┼────────────────┤
 │   A <= B   │ Tests if A is less than or equal to B.    │ IF A <= B THEN │
 ├────────────┼───────────────────────────────────────────┼────────────────┤
 │   A >= B   │ Tests if A is greater than or equal to B. │ IF A >= B THEN │
 └────────────┴───────────────────────────────────────────┴────────────────┘
   The operations should be very obvious for numerical values. For strings
   be aware that all checks are done case sensitive (i.e. "Foo" <> "foo").
   The equal/not equal check is pretty much straight forward, but for the
   less/greater checks the ASCII value of the first different character is
                          used for decision making:

   E.g. "abc" is less than "abd", because in the first difference (the 3rd
        character) the "c" has a lower ASCII value than the "d".

   This behavior may give you some subtle results, if you are not aware of
                   the ASCII values and the written case:

   E.g. "abc" is greater than "abD", because the small letters have higher
        ASCII values than the capital letters, hence "c" > "D". You may use
        LCASE$ or UCASE$ to make sure both strings have the same case.


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Basic's Rounding Functions

Rounding is used when the program needs a certain number value or type. There are 4 INTEGER or LONG Integer functions and one function each for closest SINGLE and closest DOUBLE numerical types. Closest functions use "bankers" rounding which rounds up if the decimal point value is over one half. Variable types should match the return value.
Name Description
INT(n) rounds down to lower Integer value whether positive or negative
FIX(n) rounds positive values lower and negative to a less negative Integer value
CINT(n) rounds to closest Integer. Rounds up for decimal point values over one half.
CLNG(n) rounds Integer or Long values to closest value like CINT.(values over 32767)
CSNG(n) rounds Single values to closest last decimal point value.
CDBL(n) rounds Double values to closest last decimal point value.
_ROUND rounds to closest numerical integer value in QB64 only.

Notes

  • Each of the above functions define the value's type in addition to rounding the values.
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Base Number Systems

                   Comparing the INTEGER Base Number Systems

  Decimal (base 10)    Binary (base 2)    Hexadecimal (base 16)    Octal (base 8)

                             &B                 &H HEX$(n)           &O OCT$(n)

          0                  0000                  0                     0
          1                  0001                  1                     1
          2                  0010                  2                     2
          3                  0011                  3                     3
          4                  0100                  4                     4
          5                  0101                  5                     5
          6                  0110                  6                     6
          7                  0111                  7                     7 -- maxed
          8                  1000                  8                    10
  maxed-- 9                  1001                  9                    11
         10                  1010                  A                    12
         11                  1011                  B                    13
         12                  1100                  C                    14
         13                  1101                  D                    15
         14                  1110                  E                    16
         15  -------------   1111 <--- Match --->  F  ----------------  17 -- max 2
         16                 10000                 10                    20

      When the Decimal value is 15, the other 2 base systems are all maxed out!
      The Binary values can be compared to all of the HEX value digit values so
      it is possible to convert between the two quite easily. To convert a HEX
      value to Binary just add the 4 binary digits for each HEX digit place so:

                        F      A      C      E
              &HFACE = 1111 + 1010 + 1100 + 1101 = &B1111101011001101

      To convert a Binary value to HEX you just need to divide the number into
      sections of four digits starting from the right(LSB) end. If one has less
      than 4 digits on the left end you could add the leading zeros like below:

             &B101011100010001001 = 0010 1011 1000 1000 1001
                       hexadecimal =  2  + B  + 8 +  8  + 9 = &H2B889

    See the Decimal to Binary conversion function that uses HEX$ on the &H page.


VAL converts string numbers to Decimal values.
  • VAL reads the string from left to right and converts numerical string values, - and . to decimal values until it finds a character other than those 3 characters. Commas are not read.
  • HEXadecimal and OCTal base values can be read with &H or &O.


The OCT$ string function return can be converted to a decimal value using VAL("&O" + OCT$(n)).
The HEX$ string function return can be converted to a decimal value using VAL("&H" + HEX$(n)).


STR$ converts numerical values to string characters for PRINT or variable strings. It also removes the right number PRINT space.


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Bits and Bytes

BITS
  • The MSB is the most significant(largest) bit value and LSB is the least significant bit of a binary or register memory address value. The order in which the bits are read determines the binary or decimal byte value. There are two common ways to read a byte:
  • "Big-endian": MSB is the first bit encountered, decreasing to the LSB as the last bit by position, memory address or time.
  • "Little-endian": LSB is the first bit encountered, increasing to the MSB as the last bit by position, memory address or time.
         Offset or Position:    0    1   2   3   4   5   6   7      Example: 11110000
                              ----------------------------------             --------
    Big-Endian Bit On Value:   128  64  32  16   8   4   2   1                 240
 Little-Endian Bit On Value:    1    2   4   8  16  32  64  128                 15
The big-endian method compares exponents of 2 ^ 7 down to 2 ^ 0 while the little-endian method does the opposite.
BYTES
  • INTEGER values consist of 2 bytes called the HI and LO bytes. Anytime that the number of binary digits is a multiple of 16 (2bytes, 4 bytes, etc.) and the HI byte's MSB is on(1), the value returned will be negative, even with SINGLE or DOUBLE values.
                                 16 BIT INTEGER OR REGISTER
              AH (High Byte Bits)                         AL (Low Byte Bits)
   BIT:    15    14   13   12   11   10   9   8  |   7   6    5   4    3    2   1    0
          ---------------------------------------|--------------------------------------
   HEX:   8000  4000 2000 1000  800 400  200 100 |  80   40  20   10   8    4   2    1
DEC: -32768 16384 8192 4096 2048 1024 512 256 | 128 64 32 16 8 4 2 1
The HI byte's MSB is often called the sign bit! When the highest bit is on, the signed value returned will be negative.


Example: Program displays the bits on for any integer value between -32768 and 32767 or &H80000 and &H7FFF.

DEFINT A-Z
SCREEN 12
COLOR 11: LOCATE 10, 2
 PRINT "      AH (High Register Byte Bits)           AL (Low Register Byte Bits)"
COLOR 14: LOCATE 11, 2
 PRINT "    15   14  13   12   11  10    9   8    7   6    5   4    3    2   1    0"
COLOR 13: LOCATE 14, 2
 PRINT " &H8000 4000 2000 1000 800 400  200 100  80   40  20   10   8    4   2  &H1"
COLOR 11: LOCATE 15, 2
 PRINT "-32768 16384 8192 4096 2048 1024 512 256 128  64  32   16   8    4   2    1"
FOR i = 1 TO 16
  CIRCLE (640 - (37 * i), 189), 8, 9 'place bit circles
NEXT
LINE (324, 160)-(326, 207), 11, BF 'line splits bytes
DO
  IF Num THEN
    FOR i = 15 TO 0 STEP -1
      IF (Num AND 2 ^ i) THEN
        PAINT (640 - (37 * (i + 1)), 189), 12, 9
        BinStr$ = BinStr$ + "1"
      ELSE
        PAINT (640 - (37 * (i + 1)), 189), 0, 9
        BinStr$ = BinStr$ + "0"
      END IF
    NEXT
    COLOR 10: LOCATE 16, 50: PRINT "Binary ="; VAL(BinStr$)
    COLOR 9: LOCATE 16, 10: PRINT "Decimal ="; Num;: COLOR 13: PRINT "       Hex = "; Hexa$
    Hexa$ = "": BinStr$ = ""
   END IF
   COLOR 14: LOCATE 17, 15: INPUT "Enter a decimal or HEX(&H) value (0 Quits): ", frst$
   first = VAL(frst$)
   IF first THEN
     LOCATE 17, 15: PRINT SPACE$(55)
     COLOR 13: LOCATE 17, 15: INPUT "Enter a second value: ", secnd$
     second = VAL(secnd$)
     LOCATE 17, 10: PRINT SPACE$(69)
   END IF
  Num = first + second
  Hexa$ = "&H" + HEX$(Num)
LOOP UNTIL first = 0 OR Num > 32767 OR Num < -32767
COLOR 11: LOCATE 28, 30: PRINT "Press any key to exit!";
SLEEP
SYSTEM
Code by Ted Weissgerber


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OFFSET


Warning: _OFFSET values cannot be reassigned to other variable types.


_OFFSET values can only be used in conjunction with _MEMory and DECLARE LIBRARY procedures.


See also


QB64 Programming References

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