Heat maps of variability parameters (top), g – r vs. z – W1 (middle) and W2 vs. W1 – W2 (bottom). These are the full parameter distributions of objects with light curves in PTF after cleaning and matching with other surveys as necessary. Two large clusters are observed in Α-γ-space. Selection criteria are applied to this data for analysis of candidate QSOs, stars and galaxies. log(A) is in base 10 and based on A units of in magnitudes.