SigmaSpectra is an open-source program that selects and scales a suite of earthquake motions to fit a target spectrum using the methodology of Kottke and Rathje (Earthquake Spectra, 2008). The scaling also controls
the variability within the suite of motions. The user provides the target spectrum, a library of candidate motions, and the number of motions required for the suite. The program outputs the selected motions and
scale factors.
