Histograms and Bar Charts

Output

For nominal variables, bars are distinguished by different colors. For interval variables, all bars have the same color.

To view or modify output options associated with your bar chart, click on the Output button of the variables dialog. This displays the options dialog shown in Figure 32.4.

Figure 32.4: Bar Chart Output Options Dialog


Bar Heights	labels all bars with their heights.
Variable:Names	labels the Y axis with variable names.
Variable:Labels	labels the Y axis with variable labels.
Variable:Both	labels the Y axis with both names and labels.
Orientation: Y Axis Vertical	draws the axis for the Y variable vertically. If this option is turned off, the Y axis is horizontal.
Orientation: Vertical Axis at Left	places the vertical axis at the left side of the chart. If this option is turned off, the vertical axis is at the right side of the chart.
Orientation: Horizontal Axis at Bottom	places the horizontal axis at the bottom of the chart. If this option is turned off, the horizontal axis is at the top of the chart.

You can modify other aspects of the bar chart using the bar chart pop-up menu. Click on the button at the lower left corner of the bar chart to display the pop-up menu.

[menu]
Figure 32.5: Bar Chart Pop-up Menu

Ticks...: displays the dialog in Figure 32.6 to set tick values for the variable being charted. In histograms, you can use this menu to set bar width and offset. You can set tick values for the frequency axis by clicking on the Frequency label before selecting Ticks from the pop-up menu.
Axes: toggles the display of axes.
Observations: toggles the display of observations (bars). When this menu is toggled off, observations are displayed only if selected.
Values: toggles the display of values for bar heights.
Reference Lines: toggles the display of lines that indicate the position of major ticks on the frequency axis. This option is not available unless the axes are visible.

Figure 32.6: Bar Chart Ticks Dialog

You can adjust bar width and offset interactively with the Hand Tool, as described in Chapter 12, "Examining Distributions." You can also add density curves to bar charts in distribution analyses, as described in Chapter 38, "Distribution Analyses."