Manual Reference Pages - nframe (3)
NAME
nframe(3f) - [M_calcomp:basic] start new frame (LICENSE:PD)
CONTENTS
Synopsis
Description
Example
License
SYNOPSIS
subroutine nframe()
DESCRIPTION
Terminates the current frame and resets the current pen position and origin to zero (The lower left-hand corner of the new frame).
NFRAME is a locally-developed routine.
Subroutine NFRAME allows users to define the logical beginning and ending of a plot. This capability is necessary if plots are to be drawn on a graphics device with a limited display area (e.g., a graphics terminal or microfiche/ film). A call to NFRAME enters a plot terminator in the user’s metalanguage file. All plotting data generated between calls to NFRAME is treated as a single plot by the graphics post processing procedures. The absence of calls to NFRAME results in all plotting data being processed as a single plot by the post processor (e.g., all plotting data will be drawn in a single frame on microfiche).
The call to NFRAME should be placed before the call to subroutine PLOT that is used to move the pen to the origin of the next plot. Be aware that the area encompassed by moving the pen to establish the origin of a plot is considered part of the plot and will produce a visible bottom and left margin on plot frames if no negative values are subsequently used.
As mentioned previously, a plot frame is limited to a maximum size in either the X or Y direction of 100 "CALCOMP inches." Each plot frame is initialized by a call to subroutine PLOT with the third argument (IPEN) equal to -2 or -3. For example:
CALL PLOT(0.5,1.0,-3)says to move 0.5 inches in the X-direction and 1.0 inch in the Y-direction before establishing a new origin. When establishing a new origin, all offsets are included inside the frame boundary and are therefore part of the plot frame size. If any X or Y coordinate value (plus the appropriate offset) exceeds the 100 inch limit, results are unpredictable. In programs where X and Y coordinate values exceed the scaling limit, a call to the CALCOMP routine FACTOR may be used to scale down the plot size appropriately. No additional offset is added by the call to NFRAME. Knowledge of the plot frame size in the X and Y directions will be needed to scale pen plots to actual inches with the device dependent post processing procedures. The following example is provided to assist in understanding how the frame size is determined.
EXAMPLE
Sample program
program demo_nframe use M_calcomp implicit none ! ! Perform initialization call plots(0.0,10.0,0.0,10.0) ! ! Establish origin for first plot (Negative Y values up to -0.5 are ! now permitted also) call plot( 0.0, 0.5, -3) ! ! Draw a box inside of which all lines will appear ! but notice plot frame size now includes the offset plus this box size ! Plot frame size = maximum coordinate value used + offset ! Plot frame size in the X-direction is 8 inches ! Plot frame size in the Y-direction is 9.5 inches (0.5 offset in PLOT ! call above call plot( 8.0, 0.0, 2) call plot( 8.0, 9.0, 2) call plot( 0.0, 9.0, 2) call plot( 0.0, 0.0, 2) ! ! Calls to generate first plot go here ! . ! . ! . ! Terminate first plot call nframe() ! ! Establish origin for second plot call plot(1.0, 2.0, -3) ! Plot frame size in the X-direction is 6 inches ! Plot frame size in the Y-direction is 6 inches call plot(5.0, 0.0, 2) call plot(5.0, 4.0, 2) call plot(0.0, 4.0, 2) call plot(0.0, 0.0, 2) ! ! Calls to generate second plot go here ! . ! . ! . ! Close the plot file call plot(0.0, 0.0, 999) end program demo_nframeAn inch drawn in frame 1 will not appear equal in length to an inch drawn in frame 2 because their unit-less frame sizes are not equal ( 8.5 x 9 versus 6 x 6 ) !
The size of each frame is determined by the maximum value reached in each frame relative to the ORIGINAL frame origin. Each frame, when plotted, is stretched without distortion to the maximum size it can obtain in the plotting area specified on post-processor calls (Usually the SIZE, and XI and YI parameters as described in the DOCLIB document GRPHDOC).
LICENSE
Public Domain
| nframe (3) | March 11, 2021 |
