Miscellaneous HPLOT functions.
Clear the screen. Initialize a new HIGZ picture if option ZFL or ZFL1 has been selected. Select the Normalisation Transformation number 1 (cm).
Clear the screen.
CHOPT:
Locate points on the screen using the graphics cursor and output coordinates on terminal. Control is returned when the BREAK (right) mouse button is clicked (or CRTL/E) or when 20 points are located. The optional parameter NTPRI may be specified to locate a point in the specific transformation number NTPRI. NTPRI=-1 (default) means that all the histogram transformation numbers (10, 20, etc.) have priority on transformation number 1. WKID allows to define in which window the locator is performed.
invoke when the mouse cursor enter the window.
CHOPT:
Locate a set of points using the graphics cursor. Return corresponding coordinates in vectors X and Y. If vectors X or Y do not exist, they are automatically created. Control is returned when the point is outside picture limits or when the BREAK (right) mouse button is clicked (or CRTL/E). The optional parameter NTPRI may be specified to locate a point in the specific transformation number NTPRI (see LOCATE). WKID allows to define in which window the locator is performed.
Change the contents of a histogram channel using the cursor. Position the cursor to the channel to be changed, trigger graphics input, position the cursor to the new channel value (a rubber band box is used to visualize the change), trigger graphics input to fix the new value.