Example: Lissajous Patterns
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10 ! *********************************************************************
20 ! Example: Lissajous Patterns
30 !
40 ! This example plots one sine wave vs. another. The phase
50 ! and ratio of frequencies are varied. The resulting curves
60 ! are Lissajous curves.
70 !
80 ! ***************************************************************
90 !
100 ! Set up an XY display for the curves
110 ! Most of the attributes are programmed outside the loop
120 !
130 ASSIGN @Lissajous TO WIDGET "XY GRAPH";SET ("TITLE":" Example: Lissajous Patterns","TRACE COUNT":1,"POINT CAPACITY":512,"HEIGHT":250,"WIDTH":250,"X":100,"Y":100)
140 CONTROL @Lissajous;SET ("TRACE BACKGROUND":9,"TRACE PEN":0)
150 CONTROL @Lissajous;SET ("SYSTEM MENU":"Quit")
160 ON EVENT @Lissajous,"SYSTEM MENU" GOTO Finis
170 !
180 ! Set the limits in the graph to -1 to +1 for both axes
190 !
200 CONTROL @Lissajous;SET ("CURRENT AXIS":"X","ORIGIN":-1,"RANGE":2,"SHOW NUMBERING":0,"SHOW TICKS":0)
210 CONTROL @Lissajous;SET ("CURRENT AXIS":"Y","ORIGIN":-1,"RANGE":2,"SHOW NUMBERING":0,"SHOW TICKS":0)
220 !
230 ! Two string displays which show the current values of the loop veriables
240 !
250 ASSIGN @Show_phase TO WIDGET "STRING";SET ("TITLE":" Phase","X":50,"Y":10)
260 ASSIGN @Show_ratio TO WIDGET "STRING";SET ("TITLE":" Ratio","X":250,"Y":10)
270 !
280 ! Calculate the reference sine wave and set the X data to it
290 !
300 INTEGER I,N
310 N=50
320 ALLOCATE F1(N),F2(N)
330 ALLOCATE Fbig(0:N*2)
340 FOR I=0 TO N
350 F1(I)=SIN(I*2*PI/N)
360 NEXT I
370 CONTROL @Lissajous;SET ("X DATA":F1(*))
380 !
390 ! The Ratio variable is used the vary the ratio of the frequencies
400 ! of the two sine waves
410 !
420 LOOP
430 FOR Ratio=1 TO 5
440 Tmp1=(2*PI/N)*Ratio
450 FOR I=0 TO N*2
460 Fbig(I)=SIN(I*Tmp1)
470 NEXT I
480 CONTROL @Show_ratio;SET ("VALUE":VAL$(Ratio))
490 !
500 ! This loop offsets the phase of the second sine wave
510 !
520 FOR Phase=0 TO N-1
530 CONTROL @Show_phase;SET ("VALUE":VAL$(Phase))
540 Start=Phase/360*N
550 Start=Phase
560 MAT F2=Fbig(Start:Start+N)
570 CONTROL @Lissajous;SET ("Y DATA":F2(*))
580 WAIT .1
590 NEXT Phase
600 NEXT Ratio
610 END LOOP
620 Finis: !
630 ASSIGN @Lissajous TO * ! Delete XY GRAPH widget
640 END
