Creating histogram graphs
Histograms have the advantage of being a visually strong graph type used to display continuous data in ordered columns. Histograms are useful for larger sets of data points. A histogram is essentially a frequency distribution where the source data values are grouped into bins or class intervals. The column heights represent a frequency count of the number of items falling into each bin. This means that exact data values cannot be read off the histogram and also that it is more difficult to compare multiple datasets using a histogram.
- Click the View menu, point to Graphs, then click Create.
- Click the Graph type drop-down arrow and choose the Histogram type.
- Click the Layer/Table drop-down arrow and choose the layer or table containing the data values that are to be graphed.
- Click the Value field drop-down arrow and choose the field of values to graph. The wizard shows the initial version of the graph.
- Click on the Add to legend check box if you wish to add a legend to the graph.
- Check the Show labels (marks) check box to see the bars in the histogram labeled with the range of values contained in each bin.
- Change the appearance of the bars in the histogram graph with the Color control.
Change the Number of bins control to have more or less bins in the histogram.
- Adjust the transparency of the histogram with the Transparency (%) control. By default, the histogram graph for each series is opaque (0% transparent). If you have multiple series, use the transparency setting to make visible the portions of the histogram that would otherwise be hidden.
- Uncheck the Show border check box if you do not want to see a perimeter line around the histogram.
- Uncheck the Show lines check box if you do not want to see a vertical line differentiating the bins of the histogram.
- The general properties of the graph are set on the second page of the wizard. Click Next to proceed to this second page.