XYRATIO Type: Adverb (Real) Use: The ratio in coordinate units per pixel separation along the X axis with respect to the Y axis. Null value: 0 Null value assignment is usually calculated from the pixel separations (X to Y increment) given in the image header if the axes are related (i.e. LL-MM). If the axes are unrelated (i.e. V-LL), the ratio of the Y to X windows is used (to give square plot).