IFERR...THEN...ELSE…END allows a program to intercept error conditions that otherwise would cause the program to abort. Its syntax is:

IFERR trap-clause

THEN clause_1

ELSE clause_2

END :

 

Example

 

 

IFERR

Y:

 

60/X

 

THEN

 

 

MSGBOX "Error: X is zero.":

 

ELSE

 

 

MSGBOX "Value is "Y:

 

END:

 

RUN

Runs the named program. If your program name contains

 

special characters, such as a space, then you must

 

enclose the file name in double quotes (" ").

 

RUN "program name": or RUN programname:

STOP

Stops the current program.

 

STOP:

 

Drawing commands

The drawing commands act on the display. The scale of the display depends on the current aplet's Xmin, Xmax, Ymin, and Ymax values. The following examples assume the hp 39gs default settings with the Function aplet as the current aplet.

ARC

Draws a circular arc, of given radius, whose centre is at

 

(x,y) The arc is drawn from start_angle_measurement, to

 

end_angle_measurement.

 

ARC x;y;radius;start_angle_measurement ;

 

end_angle_measurement:

Programming

18-19