Creating scatterplot graphs
A scatter graph uses the data values as x,y coordinates to plot points. The pattern may reveal a relationship between the values plotted on the grid and can show trends in the data. Scatterplot graphs are especially useful when you have a large number of data points. They are similar to line graphs, except that line graphs connect the dots or points of data to show every change.
- Click the View menu, point to Graphs, then click Create.
- Click the Graph type drop-down arrow and choose the Scatter Plot 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 Y field drop-down arrow and choose the field of values to graph. The wizard shows the initial version of the graph.
The points are initially distributed along the horizontal axis by the order of the values in the source table (record 1, record 2, and so on). Use the X field parameter to change the order of the points based on another field.
For example, you have a table with state population and area. If you set Y field to the population and X field as the default, <None>, the data points of the scatterplot will be distributed along the x-axis according to the order of the data values in the table, with the first entry in the table being the leftmost point and the last entry the rightmost.
If you then set X field to the area field, the points will be sorted with the smallest area as the leftmost point and the largest area as the rightmost. This can help you see whether there is a correlation between the population of a state and its area.
- Specify a different field with which to label the horizontal axis of the scatterplot in X label field.
- By default, the values of the input data are added to the legend of the graph. You can disable this by unchecking the Add to legend check box.
- Check the Show labels (marks) check box to mark the data points with their values. If X label field has not been set, the Y field value will be used for the label value. You can change the field that's used to label the points by changing the value in X label field.
- You can change the appearance of the markers on the graph with the Color control.
- You can change the appearance of the data points in the scatterplot with the Symbol Properties tabs. The Brush tab controls the size and markertype of the points, and the Border tab controls the width, style, and color of the outline of the point marker symbols.
- Click the Next button to proceed to the general properties page to complete your graph.