7.2.1 Simple Draw Routine (USGRPH)

This routine provides a quick and easy way to plot a set of data. A single line is enough to draw a  line graph. Below is an example of a program using this routine.

       CALL GROPN(IWS)    ! Open a device

       CALL GRFRM         ! Set a frame

       CALL GRSTRN(ITR)   ! Specify the transformation function number (may be skipped; default value is 1.)


       CALL USSTTL(....)  ! Set title (may be skipped)

       CALL USGRPH(N,X,Y) ! Plot graph



       CALL GRCLS         ! Close the device

Between GRFRM and USGRPH, the parameters for the transformation function can be set using GRPACK and SGPACK, and other parameters can be changed using USpSET. The title of the coordinate axes can be specified using USSTTL.

These routines are convenient for create a quick plot of the data. However, to place multiple line plots in a single graph or for more advanced applications such as using this routine in combination with other packages, it is better to directly use the scaling routines and the coordinate axis routines. The following is the program above is rewritten using these basic routines.

 

       CALL GROPN(IWS)    ! Open a device

       CALL GRFRM         ! Set a frame

       CALL GRSTRN(ITR)   ! Specify a transformation function number (may be skipped)



       CALL USSPNT(N,X,Y) ! Specify the data range

       CALL USPFIT        ! Set the transformation function parameters

       CALL GRSTRF        ! Make the transformation function effective



       CALL USSTTL(....)  ! Set title (may be skipped)

       CALL USDAXS        ! Plot coordinate axes



       CALL UULIN (N,X,Y) ! Draw a polyline



       CALL GRCLS         ! Close the device