Chapter 21: Using Advanced Charting Techniques
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Each axis has two sets of gridlines: major and minor. Major units display a label. Minor units are located between the
labels.
To modify the color or thickness of a set of gridlines, click one of the gridlines and use the
commands from the Chart Tools ➪ Format ➪ Shape Styles group. Or, use the controls in the
Format Major (or Format Minor) Gridlines task pane.If gridlines seem too overpowering, consider changing them to a lighter color or use one of
the dashed line options.Modifying the Axes
Charts vary in the number of axes they use. Pie, doughnut, sunburst, and treemap charts
have no axes. All 2-D charts have two axes but can have three (if you use a secondary value
axis) or four (if you use a secondary category axis in an XY chart). True 3-D charts have
three axes.Excel gives you a great deal of control over these axes via the Format Axis task pane. The
content of this task pane varies depending on the type of axis selected.Modifying the value axis
To change a value axis, right-click it and choose Format Axis. Figure 21.9 shows one panel
(Axis Options) of the Format Axis task pane for a value axis. In this case, the Axis Options
section is expanded, and the other three sections are contracted. The other icons along the
top of this task pane deal with cosmetic and number formatting for the axis.By default, Excel determines the minimum and maximum axis values automatically, based
on the numerical range of the data. To override this automatic axis scaling, enter your own
minimum and maximum values in the Bounds section. If you change these values, the word
Auto changes to a Reset button. Click Reset to revert to automatic axis scaling.Excel also adjusts the major and minor axis units automatically. Again, you can override
Excel’s choice and specify different units.Adjusting the bounds of a value axis can affect the chart’s appearance. In some cases,
manipulating the scale can present a false picture of the data. Figure 21.10 shows two line
charts that depict the same data. The chart on the right uses Excel’s default (Auto) axis
bounds values. In the chart on the left, the Minimum bound value was set to 10,000, and
the Maximum bound value was set to 500,000. The first chart makes the differences in the
data seem more prominent. The second chart gives the impression that there isn’t much
change over time.