29.9.3 XY Plots of File Data

You can produce XY plots using data contained in external files. The File XY Plot dialog box allows you to display data read from external files in an abscissa/ordinate plot form. The format of the plot file is described in Section  29.9.6.

Steps for Generating XY Plots of Data in External Files

You can create an XY plot of data contained in one or more external files using the File XY Plot dialog box (Figure  29.9.7).

Plots File Set Up...

Figure 29.9.7: The File XY Plot Dialog Box

The steps for generating a file XY plot are as follows:

1.   Load each external data file (with the format described in Section  29.9.6) by entering its name in the text field beneath the Files list and clicking on the Add... button (or pressing <Enter>). If you click Add... without specifying a name under Files (or if you specify an incorrect or duplicate name), a Select File dialog box (see Section  2.1.6) will appear and you can specify one or more files there. When a file is loaded, its name will appear in the Files list and its title will appear in the Legend Entries list. Data in all loaded files will be plotted, so if you decide not to include one of the loaded files in the plot you must select it and click the Delete button to remove it.

2.   Set any of the options described below, or modify the attributes of the axes or curves as described in Sections  29.9.9 and 29.9.10.

3.   Click the Plot button to generate an XY plot of the data associated with all loaded files.

Options for File XY Plots

The options mentioned in the procedure above include the following. You can change the plot title, legend title, or legend entry.

Changing the Plot Title

The plot title will appear in the caption box at the bottom of the graphics window. You can modify the plot title by changing the entry in the Plot Title text box in the File XY Plot dialog box (or by editing the caption box manually, as described in Section  29.2.3).

Changing the Legend Entry

When you plot data from a single file, the $y$ axis of the plot will be labeled by the "legend entry.'' To modify this label, click on the text in the Legend Entries list, edit the text that appears in the text field below the list, and then click the Change Legend Entry button (or hit <Enter>). When you next plot the data, the new legend entry will appear in the plot.

Changing the Legend Title

When you plot data from more than one file, a legend will appear in the upper left corner of the graphics window. By default, the legend will have no title. If you want to add a title, enter it in the Legend Title text field. The title will appear above the legend the next time you plot the data.

Note that you can use any of the mouse buttons to annotate the plot (see Section  29.2.4) or move the legend from its default position.