Formatting Chart Axes

In column charts, area charts, line charts, and bar charts data points are plotted on one axis (the y-axis for column, area, and line charts; the x-axis for bar charts) and data sets are grouped on the other axis. The data point axis is called the value axis, and the data set axis is called the category axis.

In scatter charts, both the x and y axes are value axes. In 2-axis charts, there are two y axes—Value Axis (Y1) and Value Axis (Y2)—which can be formatted separately. For more details about 2-axis charts, see Customizing 2-Axis and Mixed Charts.

To show or hide an axis or chart borders, set the scale (linear or log) and span of the value axis, or adjust grid and tick marks along the axes, make selections, and enter appropriate values in the Axis pane of the Chart inspector. To learn about the Inspectors, see The Inspector Window.

Many of these formatting options are also available using the format bar. Just as with the Chart inspector, the options available on the format bar are always appropriate to the type of chart you have selected. To learn about the format bar, see The Format Bar.

To open the Chart inspector:

Click Inspector in the toolbar (or choose View > Show Inspector) and click the Chart inspector button.

To place gridlines and tick marks along the chart axes:

Select the grid lines and tick marks you want from one or both of the Choose Axis Options pop-up menus.

To format the values along the value axis, do any of the following:

To set the highest number displayed on the value axis, type a number in the Maximum field under Value Axis. This value cannot be lower than the maximum value of your entire data set. If you don’t specify a number, the field displays the word “Auto,” and the value is automatically calculated based on the data.
To set the value at the origin point of the value axis, type a number in the Minimum field under Value Axis. This value cannot be greater than the minimum value of your entire data set. If you don’t specify a number, the field displays the word “Auto,” and the value is automatically calculated based on the data.
To specify the number of axis markings between zero and the minimum and maximum values on the value axis, specify a number in the Steps field under Value Axis.
To display the data values on the value axis, select Show Value Labels and/or Show Minimum Value from the Choose Axis Options pop-up menu under Value Axis.
To specify units for numbers on the value axis, select an option from the Format pop-up menu under Value Axis.
- Number:
  
  Displays the data point value with no units. In the Decimals field, specify how many decimal places you want to appear. To display negative values preceded by a minus sign or in parentheses, choose –100 or (100) from the pop-up menu. Select Separator if you want to separate the orders of magnitude on the left side of the decimal.
- Currency:
  
  Displays the data point value as a monetary amount. Select the currency unit symbol from the Symbol pop-up menu. In the Decimals field, specify how many decimal places you want to appear. To display negative values preceded by a minus sign or in parentheses, choose –100 or (100) from the pop-up menu. Select Separator if you want to separate the orders of magnitude on the left side of the decimal.
- Percentage:
  
  Displays the data point value as divided by 100. In the Decimals field, specify how many decimal places you want to appear. To display negative values preceded by a minus sign or in parentheses, choose –100 or (100) from the pop-up menu. Select Separator if you want to separate the orders of magnitude on the left side of the decimal.
- Date and Time:
  
  Displays data point values with a date and time format.
- Duration:
  
  Displays data point values as a unit of time, for example, seconds, minutes, or weeks.
- Fraction:
  
  Displays data point values less than 1 as one integer over another. (If your values are greater than 1, you won’t see any fractional representation of your data.) Choose how accurately you want the fractions rounded off in the Accuracy pop-up menu. Choosing an option such as Halves or Quarters represents the values as a portion of the total pie, rounded to the nearest division you selected.
- Scientific:
  
  Displays data point values in scientific notation, where 10 raised to a power is represented as E+ an integer. In the Decimals field, specify how many decimal places you want to appear.
- Custom:
  
  Choose a custom number format you’ve already created, or create a new one. See Using Your Own Formats for Displaying Values in Table Cells for more information.

To display category (data set) titles:

Select Show Categories from the Choose Axis Options pop-up menu under Category Axis, and then do any of the following:
To show or hide some of the category titles, do either or both of the following:
- Specify the interval at which you want category labels to appear by typing a value or using the stepper in the “Label every ... categories” field. For example, a value of 2 displays every other category title, a value or 3 displays every third category title, and so on.
- Select Show Last Category from the Choose Axis Options pop-up menu under Category Axis, if you want the title of the last category to appear.

To add or hide an axis title:

Select Show Title from the Choose Axis Options pop-up menu under Category Axis or Value Axis.
Select title text that appears and type the title you want.
To format the title’s text attributes, see Creating Outlined Text.
To hide the title, deselect the option in the same pop-up menu.

To set a linear, logarithmic, or percentage scale for the value axis:

Select Linear Scale, Log Scale, or Percentage Scale from the Choose Axis Options pop-up menu under Value Axis.

Percentage scales are available only for 2D stacked bar, column, and area charts; linear and logarithmic scales are available only for 2D charts that aren’t stacked. 3D charts can only use a linear scale. (For pie charts, you display values as percentages by choosing Show Pie Values as Percentages from the Data Point Settings pop-up menu.)

To change the color and texture of series elements, or to format data point symbols and value labels, use the Series pane of the Chart inspector. See Formatting the Elements in a Chart’s Data Series.

For formatting options that are unique to a given chart type (for example, the spacing between bars, for bar charts, or the spacing between wedges, for pie charts), see the sections specific to those chart types,

You can also show error bars and trendlines on most chart types. See Showing Error Bars in Charts and Showing Trendlines in Charts.