# Response Spectrum Wizard : User Defined Spectrum

The user-defined spectrum must be defined externally and can be imported in this dialog.

# Import

The user is given a file selection dialog to select the file to import. The files supported are:

The files must contain values of displacement / velocity / acceleration as a function of period / frequency.

The types for the abscissa (x-axis) should be one of:

  • FREQUENCY
  • PERIOD

The types for the ordinate (y-axis) should be one of:

  • DISP
  • VELOCITY
  • ACCELERATION

# Export

The user is given the option of exporting a file. This allows a file to be modified if required and then re-imported into GSA. The files supported are:

# Modify

In many cases the imported file contains the correct data but the data needs some modification, such as scaling so that the units are correct. See Modify Curve.