The following set of examples show how to set up plot layouts. None of these examples make use of any external data. The examples show how to define basic sets of plots (and some not so basic) and how to annotate them. Remember, to change the option settings for the layout of any plot you need to highlight the plot, click on edit, make the changes, and click on accept. At this point you can click on RUN in the Main Menu to see the effects of the changes.
Figure 1 shows a column of four plots. Each plot is fully defined within the Plot Layout Menu. The four plots are all placed in a single plot column and in successive plot rows. The small gap between the plots is produced by setting the Top X gap of each plot to 1.0. This includes the setting a gap for the top plot even though there is nothing plotted above it. Leaving it at 0 would make this plot extend slightly higher in Y than the lower three plots. The right Y axis annotation has been turned on in all plots and the Omit Number option for that axis in the top three plots is set to MIN which causes the lowest numerical label to be dropped. This prevents the lower labels of one plot from interfering with the upper label of the plot below it. This problem could have been avoided by using a larger gap between the plots. Only on the lower plot is the bottom X axis annotation set to YES.
There are several options which can be explored using this menu. You can change the annotation color, change what annotation is being output, change the axis scaling, and the axis min and max values. (Since no data is being plotted the plots use the axis values specified in the plot layout menu.) If you add annotation along the right-hand axis of a plot you will find that it will shrink in X relative to the other plots. For all the plots to have an identical X axis length each would have to be annotated along the right-hand Y axis. Of course if you didn’t want show the annotation you set the Omit Number option for that axis to ALL. One last thing to try is to change the row of the bottom plot from 4 to 5. This creates a 5x1 plot grid with an empty grid at row 4. Many of these options will be exercised in some of the examples below.
Figure 2 shows a 2x2 grid of plots. Each plot is fully defined within the Plot Layout Menu. The plots are 4 placed in a 2 by 2 square with plots P1 and P3 output in the first column of the plot grid and P2 and P4 output in the second. All of the plot gap options have been left at 0.0 causing the axes of adjoining plots to abut one another. Annotation on the plots whose Y axes which lie on the left and right edges of the plot grid have been turned on as has the annotation on the the plots which define the lower X base of the plot grid. The Omit Number option for the Y axes of the plots in top row are set to MIN to keep their lower annotation labels from overwriting the upper ones on the lower plots.
Figure 3 shows a mixed bag of plots defined in an overall 4x4 plot grid. While this is probably not usable plot configuration it does illustrate how to make plots span rows and columns within a grid.
While all cells within a plot grid have approximately the same dimension, the plots defined in the grid can have different dimensions. This is done by having a plot span more than one grid row and/or column. The Plot Layout defines 4x4 plot grid since the largest outer most column and lowest row occupied by a plot is 3 and 3 respectively.
Much of the pertinent layout information for this example seen in the plot layout text window. Both P1 (the upper right plot in the layout) and P7 (the lower left plot in the layout) span 3 columns in the plot grid; P3 (the middle plot on the left) spans 2 rows in the plot grid; and P4 (the center plot) spans 2 columns and 2 rows. There are several other things to note in this example. With the exception of P6 all of the plot have been defined to be non-time based. P6 has a time based annotation along its X axis while the other annotated X axes show the range set in their Minimum and Maximum axis settings. The annotation format for all annotated axes has been set to %.1f. To prevent overlap with annotation on a adjoining axes, some of the annotated axes have had the minimum or maximum annotation dropped.
Leaving plot cells within the plot grid empty can sometimes produce unexpected results as seen in Figure 4. This is a simple 3x3 plot grid in which the cell at Row 2, Column 2 has no plot definition associated with it. The problem is that the plots in the middle row do not now align with the plots in the row above and below it.
Why this happens is due to the way the plot cell widths are computed. A very simple explanation (not generally correct but is in this case) is that cell widths in a given row are determined by dividing the available space in a row by the number of cells in the row. The space available is the unused space after space for all labels has been accounted for. Because the middle row has only to account for one set of Y axis labels while the other two rows need to account for two sets of labels, it has more space to allocate to its plot cells. As a result the plots in the middle row are wider. It should be noted that we would get much the same effect if a plot had been defined in the empty plot but its right Y annotation turned off.
To force alignment in the case of the empty cell is to fill the cell with a dummy plot with its right Y annotation turned on. This is shown in the next example. The solution when a plot is defined in the cell is to turn on it right Y annotation and set the Omit Numbers for that axis to ALL. This in essence leaves room for labels which are then not output.
Dummy plots are used as place holders in a plot grid where empty cell(s), as in the above example, cause unwanted misalignment in the displayed plots. Figure 5 shows the same plot layout as in Figure 4 but with a dummy plot placed in what was the empty plot cell.
The dummy plot is the last entry in the plot layout text window. Dummy plots always have a Plot ID of _DP_. Editing the dummy plot shows its option settings in the work area. What is important to note is that the dummy plot has its right Y axis being annotated. This second set of defined Y axis labels in this row gives it the same available space for the plot cells as for the top and bottom rows. With identical cell widths, all the plots align. If the right Y axis annotation were turned off in the dummy plot the resultant plot layout would look the same as if it had not been defined.
One of the uses if the axis gap options is to allow a plots to expand into blank or unused space within a plot grid. Figure 6 shows a 3x3 plot grid in which the center plot is not defined. It then uses a negative plot gap to pull the Y axes of the two plots on either side of the unfilled cell into the vacant area. In addition using a %.1f format for the numerical annotation along the Y axes leaves more room than necessary along the outer Y boundary of the plot grid (program budgets space for Y axis labels to fit a format of %.2e) and a negative plot gap is applied to all of the outer Y axes to recover some of this space.
Both of the negative gap applications are seen in the plot layout definitions. All of the plots in column 0 in the plot grid have a gap of -5 associated with their left Y axis. This pulls those axis 5 characters to the left to recover some of the extra space created by using a %.1f annotation format. Keeping the gap the same for these plots keeps their left edges in alignment. The center left plot has a gap of -5 along the right Y axis to pull that axis to the right to cover part of the hole in the center created by the unfilled plot cell. The same gap is applied to the left Y axis of the right center plot to let it expand into the vacant center cell. All of the plots in column 2 have a right Y gap of -5 to recover some of the extra space allowed for the default annotation format.
There are a number of options which deal with the plot axes and the associated numerical annotation. Figure 7 illustrates the effects of several options by applying them to the four axes in the displayed plot. The example shows the effects of changes in Scaling, Major and Minor Ticks, Number Format, and Text Size options.
Figure 8 shows the same basic plot layout as shown in Figure 7 but shows the effects of changes in the options Number Color, Tick Format and Bold Number. The tick format options apply to both the major and minor tick marks except SPAN which applies only to the major tick marks. In the latter case the minor tick marks always assume a format of INSIDE.
Adding a colorbar and/or a grid to a plot is done within the plot layout menu. Figure 9 shows the addition of two colorbars as well as grids within two plots.
Plot grids have been added to the plots P1 and P3. This is done by setting the Grid option to YES in those plot definitions. The grid characteristics (color, line style, direction, overlay or underlay) are set globally in the Plot SetUp menu. Setting the Show Colorbar option to YES in P1 adds a colorbar to the plot. The colorbar placement was to the right of the plot and its orientation was vertical. Setting Span to 3 allows the colorbar to output against the first three plots in the column. The colorbar characteristics (annotation, etc) were set under the CBar axis options.
The colorbar on the lower plot (P4) was set to be output below the plot and with an orientation of RHORIZONTAL. The format was changed from the default %.2e to %.1f.
If you want all of the plots to align within the grid they you would specify the colorbar span in P1 as 3,1 rather than 3. The ,1 adds room for the color bar to the next row without it being output in that row.