plgdidev: Get parameters that define current device-space window

Get relative margin width, aspect ratio, and relative justification that define current device-space window. If plsdidev has not been called the default values pointed to by p_mar, p_aspect, p_jx, and p_jy will all be 0.

p_mar (PLFLT *, output) Pointer to relative margin width. p_aspect (PLFLT *, output) Pointer to aspect ratio. p_jx (PLFLT *, output) Pointer to relative justification in x. p_jy (PLFLT *, output) Pointer to relative justification in y.

Redacted form: plgdidev(p_mar, p_aspect, p_jx, p_jy)

This function is used in example 31.