User Guide: Attenuation Relationship Plotter

This short guide explains the basic steps required to plot and compare the Attenuation Ralationships implemented in OpenSHA.

Creating a Plot

  1. Select an Attenuation Relationship from the "Choose Model" combo box (located directly above the plot window).
  2. Choose an IMT from the combo box at the upper right (the options will depend on what's supported by your chosen Attenuation Relationship)
  3. Below that, choose from among the following to plot on the Y-axis:
    • Median
    • Standard Deviation
    • Exceedance Prob (for specified IML)
    • IML at Exceedance Prob
  4. Next, choose what you want to plot on the X-axis. The options are generally any parameter applicable to your chosen attenuation relationship that represents a numerical value (the options also depend on what you've chosen for the Y-axis).
  5. Finally, set all the other parameters that your chosen attenuation relationship depends upon (the list, which is on the lower right, depends on what you've chosen for the Y-axis). HINT: mousing over the parameter name should give you more info about that Parameter, and mousing over where you enter numerical values will show any limits on the allowed values for the parameter
  6. Click the "Add Curve" button to calculate and show the plot.

You can add multiple curves, but the plot will automatically clear if you change what's plotted on either axis (e.g., you can't have both magnitude and distance on the X-axis; however, you can plot different Distance Parameters simultaneously on the X-axis).

Other Options

  • The "Clear Plot" button clears the plot.
  • The "Peel-Off" button sets the current plot aside in a new window (e.g., to save it while you generate new plots).
  • The "Add Data Points" button allows you to add your own data (e.g., values observed from an actual earthquake).
  • The functionality of the other buttons at the bottom of the plot window should be self explanatory.

Known Issues

  • You cannot currently set how the X-axis is discretized, which may be frustrating if you want to know the Y-axis value for an exact X-axis value. You can use the "Individual Value" option under the X-axis combo box to show the Y-axis value for a specific set of parameter values.
  • If, when you click the "Add Curve" button, you get a message asking whether you want to violate a "Warning Constraint" of a parameter (e.g., if you choose a Magnitude outside the range sanctioned by the chosen attenuation relationship), you may need to click the "Add Curve" button again to generate the plot (if you've accepted the value).