GSLIB Help Page: BACKTR

Description:

Back transform normal scores values according to a table look up

Parameters:

datafl: a data file in simplified GeoEAS format containing the
normal scores.

ivr: the column number for the normal scores.

tmin and tmax: all values strictly less than tmin
and strictly greater than tmax are ignored.

outfl: the output file containing the back transformed values.

transfl: an input file containing the transformation lookup
table, i.e., pairs of z and y values with z
being the original data values or class bound values and y
being the corresponding normal scores values. This is an input file
that corresponds to the table written out by nscore,
sgsim,

zmin and zmax: are the minimum and maximum values to
be used for extrapolation in the tails.

ltail and ltpar specify the back transformation
implementation in the lower tail of the distribution:
ltail=1 implements linear interpolation to
the lower limit zmin and ltail=2 implements power model
interpolation, with w=ltpar to the lower limit zmin

Linear interpolation is used between known data values.

utail and utpar specify the back transformation
implementation in the upper tail of the distribution:
utail=1 implements linear interpolation to the upper
limit zmax utail=2 power model interpolation,
with w=utpar to the upper limit zmax and
utail=4 implements hyperbolic model extrapolation to the
upper limit zmax with w = utpar