Once the new analysis has been defined, and the user has all of the information defined on the General, Variable A, Variable B, Response Curves tabs, performing the computations is simply a matter of pressing the Compute button at the bottom of the Coincident Frequency Analysis editor. If the computations are successful, the user will receive a message that says "Compute Complete". At this point, the user can begin to review the results.

The following describes how the variable C coincident frequency curve is computed.

  1. The program uses the variable A frequency curve(s) and the variable A values in the response curves table to assign a frequency of exceedance to each variable C value in the response curves table.
  2. The program finds the minimum and maximum values of variable C in the response curves table.
  3. The program defines 100 evenly spaced values of variable C in-between the minimum and maximum values (100 values include the minimum and maximum values).
  4. For each variable C from step 3, the program will look-up the exceedance frequency value from each response curve in step 1 and multiply by the corresponding proportion of time (using the probability defined on the Variable B tab) obtained from the variable B index value. These "weighted" values from each response curve are summed to compute the variable C frequency curve.
  5. The curve is interpolated to the selected exceedance ordinates defined on the General tab.

Multiple coincident frequency analyses can be computed using the Compute Manager. Select the Analysis | Compute Manager menu option to open the Compute Manager. Select the analyses to be computed and then press the Compute button. Close the compute dialogs and Compute Manager when the program finishes computing the analyses.