Turtle graphics

[1micha.elok]

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For smaller programs you could skip that part completely. 
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Thank you for your response. I decided to make a small experiment, 
- The first experiment : I used sprawdz () which has katzolwia> 360 and katzolwia<0
- The second experiment :  I skipped sprawdz () 

The results are
- The first experiment produced some "shifted green lines"
- The second experiment produced a clean blue line

   

Code:

set window "Turtle Proof",640,360

reset() 'set angle to 0
set color 0,0,0;cls 'clear screen
iteration = 100

' First Experiment
' Use sprawdz () which has katzolwia> 360 and katzolwia<0
set color 0,255,0 'green
goxy(300,120)
for i = 1 to iteration
    forward(50)
    turnleft(45)
next

' Second Experiment
' Skip sprawdz () which has katzolwia> 360 and katzolwia<0
set color 0,0,255 'blue
goxy(300,220)
for i = 1 to iteration
    forward(50)
    turnleft3(45)
next

'pause
pln "Press ENTER to quit"
temp = rln()