'
' Optimize Your AmigaBasic Programs For Speed 
'
' By Stephen R. Pietrowicz
'
' Listing one - Plotting example
'

DEF FNa(t) = (100/360*t)/3

'
' Draw each of the plots one at a time
' and report all times when done
'
CLS
GOSUB SlowPlot
FOR i = 1 TO 10000:NEXT i

CLS
GOSUB QuickPlot
FOR i = 1 TO 10000:NEXT i

CLS
GOSUB QuickerPlot

LOCATE 1,1
PRINT "SlowPlot:    Begin -- ";a1$;" End -- ";a2$
PRINT "QuickPlot:   Begin -- ";b1$;" End -- ";b2$
PRINT "QuickerPlot: Begin -- ";c1$;" End -- ";c2$
END

SlowPlot:
PRINT "SlowPlot"
a1$ = TIME$   
FOR j = 20 TO 100 STEP 20
   FOR x = -150 TO -1 STEP 0.2
'
'     First draw right side
'
      y = SIN(FNa(x))/(FNa(x))*j+50
      PSET (x+150,y),1
   NEXT x
   FOR x = 1 TO 150 STEP 0.2
'
'      Now draw left side
'
       y = SIN(FNa(x))/(FNa(x))*j+50
       PSET (x+150,y),1
   NEXT x
NEXT j
a2$ = TIME$
RETURN

QuickPlot:
PRINT "QuickPlot"
b1$ = TIME$
FOR j = 20 TO 100 STEP 20
   FOR x = 1 TO 150 STEP 0.2
      sy = x*0.0925926
      y1 = SIN(sy)/sy*j+50
      PSET (150-x,y1),1
      PSET (x+150,y1),1
   NEXT x
NEXT j
b2$ = TIME$
RETURN

QuickerPlot:
PRINT "QuickerPlot"
c1$ = TIME$
FOR x = 1 TO 150 STEP 0.2
    sy = x*0.0925926
    SinTemp = SIN(sy)/sy
    FOR j = 20 TO 100 STEP 20
       y1 = SinTemp*j+50
       PSET (150-x,y1),1
       PSET (x+150,y1),1
    NEXT j
NEXT x
c2$ = TIME$
RETURN