artificial net attractors

[BSpinoza]

This program generates an endless succession of artificial net attractors,
by a program of J.C.Sprott from 1989.

A description you will find in the following paper:

https://sprott.physics.wisc.edu/pubs/paper232.pdf

I made small changes to adapt it into QB64.

Code: (Select All)

' program: neutal_net_attractors.bas
'          by J. C. Sprott
'
' adapted to QB64 by BSpinoza
'
' This program produces neural net attractors,
' it generates endless succession of artificial neural net attractors
' Copyright (c) 1997 by J. C. Sprott

SCREEN _NEWIMAGE(880, 650, 256)
WINDOW (-5, -5)-(680, 410)
N% = 4 'Number of neurons
D% = 16 'Number of inputs (dimension)
s = .5 'Scaling factor (network gain)
tmax& = 80000 'Number of iterations
sw% = 638 '319 'Screen width - 1
sh% = 399 '199 'Screen height - 1
nc% = 254 'Number of colors - 2
DIM w(N%, D%), B(N%, D%), x(N%), y(D%), PAL&(nc% + 1)
PAL&(0) = 65536 * 63 + 256 * 63 + 63 'PAL&(0) IS WHITE
PAL&(1) = 65536 * 55 + 256 * 55 + 55 'PAL&(1) IS GRAY
FOR i% = 2 TO nc% + 1
    B% = INT(32 + 32 * COS(.02464 * i%))
    G% = INT(32 + 32 * COS(.02464 * i% + 4.1888))
    R% = INT(32 + 32 * COS(.02464 * i% + 2.0944))
    PAL&(i%) = 65536 * B% + 256 * G% + R%
NEXT i%
RANDOMIZE TIMER
WHILE INKEY$ <> CHR$(27)
    _DELAY 0.2
    CLS
    PALETTE USING PAL&(0)
    p& = 0
    FOR i% = 1 TO N%
        FOR j% = 1 TO D%
            w(i%, j%) = 1 - 2 * RND
        NEXT j%
        B(i%, 1) = s * RND
        x(i%) = .5
    NEXT i%
    FOR t& = 1 TO tmax&
        y(0) = 0
        FOR i% = 1 TO N%
            y(0) = y(0) + B(i%, 1) * x(i%)
        NEXT i%
        FOR j% = D% TO 1 STEP -1
            y(j%) = y(j% - 1)
        NEXT j%
        FOR i% = 1 TO N%
            u = 0
            FOR j% = 1 TO D%
                u = u + w(i%, j%) * y(j%)
            NEXT j%
            x(i%) = 1 - 2 / (EXP(2 * u) + 1)
        NEXT i%
        IF t& > tmax& / 50 THEN
            IF 10 * p& + 50 < t& - tmax& / 50 THEN t& = tmax&
            x% = .5 * (sw% + sw% * x(1))
            y% = .5 * (sh% - sh% * x(2))
            z% = .025 * (sw% + sw% * x(3))
            c% = 2 + INT(nc% * (.5 * x(4) + .5))
            IF POINT(x%, y%) < 2 THEN p& = p& + 1
            IF c% > POINT(x%, y%) THEN PSET (x%, y%), c%
            x% = x% + z%: y% = y% + z%
            IF POINT(x%, y%) = 0 THEN PSET (x%, y%), 1
        END IF
    NEXT t&
WEND
END