Improving an X-Y plot in Excel (alternative view with large screen shots)

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Improving an X-Y plot in Excel

The plot can now be formatted. Click the plot and “Chart Tools” appear. One can now select various options in turn. The order chosen below is not critical.

Firstly, insert a centred title above the plot, e.g. the data set name:

A chart title can be useful when working with many data sets. In this case, the data set identifier has been used. In a publication, this would normally be omitted and the plot would be shown with a proper figure caption below it to explain the data.

Next insert a title for the Y-axis (rotated by 90&\deg;). PXRD data is usually shown with intensity in counts on the Y-axis:

Note the fact that sometimes the data is not true counts due to scaling, and that sometimes counts per second (cps) or relative / normalised intensity are also used on the Y-axis.

Insert a title for the X-axis (below the plot). PXRD data is usually shown with the 2θ scale in degrees:

Note that sometimes it can be useful to plot the data in 1/d (but not in d) (in Å⁻¹), which is wavelength independent.

Delete the gridlines. A right click of the mouse when pointing at the gridlines enables them to be deleted:

Gridlines (horizontal or vertical) should not normally appear on publication quality plots as they may obscure the data.

Click on the plot area and format it:

Set to no fill and use a black solid-line border of, say, 1.5 pt^† line thickness:

Click near the x- and y-axes and format each of these in turn. Use the same solid black line thickness for each. At the same time, set the number of decimal places for the numbers to zero, and choose sensible plots limits and intervals for the values displayed on the axes:

Note that there are no peaks below 10° for this sample and that the intensity above 90° is reduced by the collimator, hence the choice of X-scale limits in this instance.

The data series legend defaults to outside the plot area, which is wasteful on space. Often it can be deleted if only one data set is displayed, but in this case change it to overlay on the plot as more data sets will be plotted later:

Right click (just once) on the data to select and format the data series. For a single data series, a solid black line should always be chosen (do not use colour gratuitously!). The line thickness was chosen here to be, say, 1 pt. The line on a PXRD plot should be relatively thin unless the X-scale has beeen expanded.

Now click on the text on the X- and Y-axes in turn and set the font size larger. This is crucial as the text on the plot will appear much smaller when the chart is copied and pasted into a Microsoft Word document as a picture:

Finally, with multiple data sets it is useful to assign the data series a more useful name. This can be done by a right mouse click on the graph to select data source:

Then choose Edit to access the selected data set series name:

The only parameter to change is the series name. Simple type in a new name (as a text string) - in this instance I used “Hydroxyapatite standard”. Finally, Don’t forget to increase the size of the text used for the legend:

The final plot after all these changes looks like this:

^†Line thicknesses are often given in points and there are 72 points to 1 inch. Hence 1.5 pt is approx 0.5 mm.

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