# Categorical scale

This topic is about categorical graph scales, such as the x-axis on a bar chart. For information on other scale types, click one of the following links.

## Show or hide scale elements

Graph scale elements are axis lines, axis labels, tick marks, and tick labels. You can display these elements on the high side or the low side of the graph's data region.

For example, on the following individual value plot, the continuous (y) scale displays tick labels with major and minor tick marks on the low side. The categorical (x) scale displays tick labels with tick marks on the low side. Axis lines are on all sides.
To specify which elements to include when you create a graph, click Scale, then select the elements on the Axes and Ticks tab. To change or add the elements on an existing graph, use the following steps:
1. Double-click the graph.
2. Double-click the scale to open the Edit Scale dialog box.
3. On the Show tab, select the elements to show.

## Transpose the value scale and the category scale

To transpose the x- and y- scales when you create a graph, click Scale, then select Transpose value and category scales on the Axes and Ticks tab. To transpose scales on an existing graph, use the following steps:
1. Double-click the graph.
2. Double-click the scale to open the Edit Scale dialog box.
3. On the Scale tab, select Transpose value and category scales.

## Innermost and outermost scales on a graph

Minitab uses the terms "innermost" and "outermost" to indicate the relative position of the scales for multiple levels of groups displayed on a graph.

For a horizontal scale, outermost refers to the scale at the bottom of the graph, and innermost refers to the scale farthest from the bottom, closest to the horizontal axis.

Outermost is also sometimes referred to as Level 1. The scale directly above the Level 1 scale is the Level 2 scale, and so on.

For a vertical scale, outermost refers to the scale to the far left, and innermost refers to the scale closest to the vertical axis.

When you create a graph with grouping variables, the order that you enter the variables in the dialog box determines which variables are defined as innermost or outermost. Minitab uses the first variable that you enter as the outermost variable. The subsequent scale levels then follow the order of the variables.

## Remove some of the innermost category labels

The innermost category labels are the labels that are closest to the axis line. By default, all the category labels are displayed. For example, the innermost category labels on this bar chart are Q1, Q2, Q3, and Q4.
To remove some of the innermost labels, in order to make the display less crowded, use the following steps:
1. Double-click the graph.
2. Double-click the scale to open the Edit Scale dialog box.
3. On the Scale tab, under Ticks for Innermost Displayed Category Labels, deselect Auto for Tick start or Tick increment, then specify the settings.
For example, on the first bar chart below, The Tick increment is set to 2 so that every other tick mark is displayed. On the second bar chart, the Tick start is set to 2, so that the labels start with the second tick mark instead of the first.

## Change the space between the groups

To change the space between groups, use the following steps:
1. Double-click the graph.
2. Double-click the scale to open the Edit Scale dialog box.
3. On the Scale tab, under Space Between Scale Categories, you can specify the following:
Gap within clusters
To specify the space between items in a cluster, deselect Auto, then enter a gap.
Gap between clusters
To specify the space between clusters, deselect Auto, then enter a gap.
For example, the first chart below shows the default space between groups. The second chart shows the maximum space between groups. The second chart also shows gaps between the bars that are within each cluster.

## Include empty groups on the scale

(This option is available only with multiple level categorical scales.) By default, Minitab includes all possible groups on a graph, even if there are no data for a group. To exclude empty cells on the scale or the legend of an existing graph, use the following steps:
1. Double-click the graph.
2. Double-click the scale to open the Edit Scale dialog box.
3. On the Scale tab, deselect Include empty cells.
For example, the following bar chart includes a tick mark for group A2, but no bar. A2 is an empty cell because there are no rows in the worksheet that contain an A in column C1 and a 2 in column C2.

## Change the tick mark labels and axis labels

### Multi-level scale

To specify custom text for tick mark labels and axis labels on a scale that includes multiple levels, use the following steps:
1. Double-click the graph.
2. Double-click the scale to open the Edit Scale dialog box.
3. Select the tab to make the edits that you want.
• Labels: Deselect Auto, and enter the custom labels, separated by spaces.
• Font: You can edit the font for the tick mark labels.
• Alignment: You can change the angle of tick mark labels.
For example, the levels of Activity are coded in the worksheet as the values, 1, 2, and 3. The custom tick mark labels in the second graph are more descriptive than the default tick marks.
###### Tip

You can also use Data > Recode to change coded values in the worksheet to values that are more descriptive. For more information, go to Overview for Recode.

### Single-level scale

To specify custom text for tick mark labels on a single-level scale, use the following steps:
1. Double-click the graph.
2. Double-click the scale to open the Edit Scale dialog box.
3. Select the tab to make the edits that you want.
• Labels Select Specified and enter the custom labels, separated by spaces.
• Font: You can edit the font for the tick mark labels.
• Alignment: You can change the angle of tick mark labels.
To edit the axis label on a single-level scale,
1. Double-click the graph.
2. Double-click the axis label to open the Edit Axis Label dialog box.
3. Select the tab to make the edits that you want.
• Font: Edit the text, and the font.
• Alignment: Specify the text angle and the position relative to the default location.
• Show: Specify the location on the graph where you want the label to display.

## Same scale range for all panels

(Matrix plot only)
1. Double-click the graph.
2. Double-click the scale to open the Edit Scale dialog box.
3. On the Scale tab, selectSame scale range for all panels to standardize the range for the selected scale for all plots in the matrix plot.