CI - Circle plot ; CI r(, qd)[;] - Page 363

CHAPTER 9 HP-GL - 12 

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Plotting is performed only when the pen is down. 

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When the pen is up,  plotting is not performed but the cursor position moves to the plot end point. 

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When scaling has been performed,  the cursor is moved by relative coordinates in user units. 

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Also, when scaling has been performed, the values for X and Y are real  numbers. 

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When there is no scaling,  the cursor is moved by relative coordinates in graphics units. 

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When there is no scaling, the coordinate values for X and Y are integer numbers. 

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The value for qc is a clamped real number. 

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When qc is positive, counterclockwise plotting from the current point is performed. 

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When qc is negative, plotting is made clockwise from the current position. 

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The value for qd is a clamped real number. 

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When qd is not specified,  the chord angle is the default value ( 5 degrees ). 

10 '*** AREX1 *** 
20 LPRINT "IN;SP1;IP2650,1325,7650,6325;" 
30 LPRINT "SC-100,100,-100,100;" 
40 LPRINT "PA-80,-80;PD;AR0,50,90;AR50,0,90;PU;" 
50 END 
 
<Sample 69> 
 
10 ' *** AREX2 *** 
20 LPRINT "IN;SP1;IP2650,1325,7650,6325;" 
30 LPRINT "SC-100,100,-100,100;" 
40 LPRINT "PA-100,70;PD;PR30,0;AR-,-70,-90;AR70,0,90;PR60,0;PU;" 
50 END 
100 END 
 
<Sample 70> 

CI - Circle plot 

CI r(, qd)[;] 

r : Radius of circle ( in user units or graphic units ) 
qd : Chord angle ( in degrees ) 

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Plots a circle centred on the current position with a radius r and chord angle qd. 

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After plotting, the cursor returns to its point of origin at the centre of the circle. 

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Plotting is performed whether the pen is up or down. 

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When scaling has been performed, the circle is plotted in user units. 

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Also, when scaling has been performed, the value for r is a real number. 

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When scaling is off, the circle is plotted in graphics units. 

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When there is no scaling, the coordinate value for r is an integer number. 

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When qd is not specified,  the chord angle is the default value (5 degrees). 

Current position

Chord angle

Radius