1000 REM FOUR-D MAP SEARCH
1020 DIM XS(499), YS(499), ZS(499), WS(499), A(504), V(99), XY(4), XN(4), COLR%(15)
1070 D% = 4                     'Dimension of system
1120 TRD% = 0                   'Display third dimension as projection

1540 W = .05
1550 XE = X + .000001: YE = Y: ZE = Z: WE = W
1610 WMIN = XMIN: WMAX = XMAX

1720 M% = 1: XY(1) = X: XY(2) = Y: XY(3) = Z: XY(4) = W
2010 M% = M% - 1: XNEW = XN(1): YNEW = XN(2): ZNEW = XN(3): WNEW = XN(4)

2180    IF W < WMIN THEN WMIN = W
2190    IF W > WMAX THEN WMAX = W
2210 XS(P%) = X: YS(P%) = Y: ZS(P%) = Z: WS(P%) = W

2410 IF ABS(XNEW) + ABS(YNEW) + ABS(ZNEW) + ABS(WNEW) > 1000000! THEN T% = 2
2470 IF ABS(XNEW - X) + ABS(YNEW - Y) + ABS(ZNEW - Z) + ABS(WNEW - W) < .000001 THEN T% = 2
2540 W = WNEW

2910 XSAVE = XNEW: YSAVE = YNEW: ZSAVE = ZNEW: WSAVE = WNEW
2920 X = XE: Y = YE: Z = ZE: W = WE: N = N - 1
2950 DLZ = ZNEW - ZSAVE: DLW = WNEW - WSAVE
2960 DL2 = DLX * DLX + DLY * DLY + DLZ * DLZ + DLW * DLW
3010    ZE = ZSAVE + RS * (ZNEW - ZSAVE): WE = WSAVE + RS * (WNEW - WSAVE)
3020    XNEW = XSAVE: YNEW = YSAVE: ZNEW = ZSAVE: WNEW = WSAVE

3150 IF WMAX - WMIN < .000001 THEN WMIN = WMIN - .0000005: WMAX = WMAX + .0000005

3680 IF Q$ = "D" THEN D% = 1 + (D% MOD 4): T% = 1

3920 IF N = 1000 THEN D2MAX = (XMAX - XMIN) ^ 2 + (YMAX - YMIN) ^ 2 + (ZMAX - ZMIN) ^ 2 + (WMAX - WMIN) ^ 2
3940 DX = XNEW - XS(J%): DY = YNEW - YS(J%): DZ = ZNEW - ZS(J%): DW = WNEW - WS(J%)
3950 D2 = DX * DX + DY * DY + DZ * DZ + DW * DW

4760 IF D% > 2 THEN FOR I% = 3 TO D%: M% = M% / (I% - 1): NEXT I%