You can use the Graph Tools | Plot Tools | Calculate Area command to compute the area under any line/scatter plot, ribbon/wall plot, or 3D XYZ line/scatter plot.
Grapher can calculate the area under a curve to any baseline value. When calculating the area for 3D XYZ line/scatter plots, the area is calculated only for the XY plane. Once calculated, the area beneath the curve is reported in XY units with zero used as a baseline.
Calculating the area under a curve:
- Create a line/scatter, ribbon/wall, or 3D XYZ line/scatter plot using the Home | New Graph | Basic commands.
- Click on the plot to select it.
- Click the Graph Tools | Plot Tools | Calculate Area command.
- Enter a baseline value (Y value to calculate the area down to, default is zero) into the Area Baseline Value dialog and click OK.
- A Grapher - Report window opens containing the area and information such as the data file, X column, and Y column used to create the plot. The area is reported in the graph's XY units.
Tips for calculating area:
- Grapher calculates the area between the plot and baseline value entered in the Area Baseline Value dialog. If any part of the plot extends below the baseline value, a negative area will be calculated. This negative value will then be added to the total area.
- The area report displays calculations for: Above Baseline Area, Below Baseline Area, and Total Area.
- The units for the area are X units * Y units. For most situations, the X and Y values should be in the same units before using this command for the calculated area value to make sense.
Updated May 2023