Merging pictures

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                 |CALL  IZMERG (PNAME,X0,Y0,SCALE,CHOPT) |
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Action: This routine allows a picture to be merged with the current one. Parameter Description:
PNAME
CHARACTER variable with the picture's name.
X0
x coordinate in normalized device coordinates where pictures have to be merged.
Y0
y coordinate in normalized device coordinates where pictures have to be merged.
SCALE
Scale factor to be applied to picture PNAME (0.<=SCALE< =1.).
CHOPT
Character variable specifying the option desired
'D'
The new current picture is displayed before the merge operation.