Chart types

Line

This is the default chart type in Source. Selecting a result in the tree menu on the left side of the Result Manager window will display a line graph (see Figure 1).

The contextual menu (Figure 1, Figure 2) can be used to do the following.

• Open the Chart Settings dialog by selecting Properties. Synonymous with the Edit Graph Properties button in the 
• Allow Hint. If you select this, hovering over the chart displays a tooltip of the x and y coordinates of values at these tracing points. This is synonymous with the Hint button on the chart toolbar. 
• Reset Zoom, which resets the zoom level of the chart to 100%. 
• Return to the Previous Zoom level.
• Hide or Show Legend.
• Add Annotation adds a note to your chart that either moves when you zoom or pan, or that stays static. These are shown in the drop down menu as, respectively, Absolute - Non moving and Relative - Moves with Zoom/Pan. 
  • To create a new note, choose Add Annotation. This creates a note called New annotation. 
  • Double click on the note to edit the text. The font size, style and colour of the note can be changed in Chart area settings; and
  • To remove an annotation, click on the annotation, right click, then choose Delete Selected annotations.
• Delete Series when the chart shows more than one series (Figure 2)

Figure 1. Line graph

Figure 2. Contextual Menu for chart with multiple series

Exceedance

An exceedance graph keeps the y-axis constant relative to a line chart, but calculates the probability of exceeding Y-axis values on the X-axis (Figure 3). The contextual menu is the same as that for a line graph. 

Figure 3. Exceedance graph

Cumulative

A cumulative graph displays the cumulative total (on the y-axis) over time (Figure 4). The contextual menu is the same as that of the line graph.

Figure 4. Cumulative graph

Difference

The x-axis remains unchanged relative to a line chart, and y = 0 represents the baseline (Figure 5). Differences between each overlaid result and the reference series are plotted. By default, the result loaded into the custom chart first will be used as the reference series. To change this, go to Chart Settings » Charts and modify Chart Type Reference Series. The contextual menu is the same as that of a line chart with multiple series. See also Naming conventions of difference, double mass and scatter statistics.

Figure 5. Difference graph

Residual mass

This graph is a plot of the cumulative deviations from the mean of a time series (Figure 6). To calculate the residual mass, subtract the mean of the time series from each value (to get residuals) and cumulate. It ignores nulls when calculating the mean. For multiple series, data across all series is ignored on dates when there is a null in any series. The contextual menu is the same as that of a line graph.

Figure 6. Residual mass graph

Scatter

In this graph type, the y-values from two time series are grouped into pairs based on common x-values (times) in the original results (Figure 7). Then these pairs are plotted as (x, y) coordinates; the y-values from the reference series are plotted on the x-axis.  By default, the result loaded into the custom chart first will be used as the reference series. To change this, go to Chart Settings » Charts and modify Chart Type Reference Series. The contextual menu is the same as that of a line graph with multiple series and so includes the Delete Series option allowing you to delete a series used in the graph. See also Naming conventions of difference, double mass and scatter statistics.

A scatter graph:

• Shows the correlation between two results;
• The equation at the bottom right is the regression line; and

• Setting the y-Intercept to 0 forces the line through the graph's origin.

Figure 7. Scatter plot

Double mass

This is a scatter plot comparing the cumulative totals for two results, this can be useful for comparing a number of rainfall stations (Figure 6).. For each result, the cumulative total of y-values is calculated over time. Then, the y-values from the two results are grouped into pairs based on common x-values (times) in the original results, and these pairs are plotted as (x, y) coordinates; the cumulative y-values from the reference series are plotted on the x-axis. By default, the result loaded into the custom chart first will be used as the reference series. To change this, go to Chart Settings » Charts and modify Chart Type Reference Series.  The contextual menu is the same as that of a line graph with multiple series and so includes the Delete Series option allowing you to delete a series used in the graph.  See also Naming conventions of difference, double mass and scatter statistics.

Figure 6. Double mass graph

Frequency histogram

A frequency histogram shows how the data values are distributed. Set the number of bins your data is divided into using Histogram Interval and select Apply to Chart. Note that entering small values for large data sets will increase computational time. The contextual menu is similar to that of a line graph with an additional item - Label Y Values displays the y-value of each bar (enabled in Figure 8).

Figure 8. Frequency histogram

Bar

This type of graph displays each point as a bar and is similar to the line graph and the contextual menu is the same as that of a line graph.

Figure 9. Bar graph