The x- and y-axes in a R coordinate both range from 0 to 1,
and the frame has an aspect ratio of 1:1.
In contrast, actual devices have various aspect ratios.
When the aspect ratios of the frame and the device are different,
the workstation transformation is normally set to
inscribe the largest frame at the center of the device
when sgfrm is called.
However, in some cases, you may want to use the full area of the device,
or to set some margin around the figure.
In such a case, the GRPH1/SLPACK is used.
The SLPACK is basically used for setting the workstation transformations,
and it contains functions for changing the aspect ratio of the frame,
as well as placing character strings such as titles in the margin,
and placing several frames in a single page.
Such functions are called the layout function.
To use these layout functions, first open the device and then make the appropriate settings before calling sgfrm. For example,
NumRu::DCL.sgopn(iws)
CALL SGDIV('S', 4, 3) ! Divide page into 4 n 3.
CALL sgfrm
. . . . . . . .
CALL sgfrm
. . . . . . . .
CALL sgcls
A page will now be set to contain 12 frames.