Z (Elevation) Transformations

For z distributions which are skewed, several transformations on Create derivative grid menu option can spread out colors and better show the distribution.  The colors will not be evenly distributed on the z scale.

Natural log.

  • Cannot be done for negative z values.
  • Emphasizes the low values.
Log base 10
  • Cannot be done for negative z values.
  • Emphasizes the low values.

Normalized.

  • 0 is the mean
  • positive values are in standard deviations above mean
  •  negative values standard deviations below mean.
Percentiles.  Go from 0 to 100; 50 is median elevation.

Last revision 3/18/2013