The features described in this topic are obsolete
and should not be used in new IDL code.

REGRESS

The following arguments and keywords to REGRESS are obsolete.

Arguments

Weights

An Npoints-element vector of weights for each equation. For instrumental (Gaussian) weighting, set Weights_i = 1.0/standard_deviation(Y_i)². For statistical (Poisson) weighting, set Weights_i = 1.0/Y_i. For no weighting, set Weights_i = 1.0, and set the RELATIVE_WEIGHT keyword.

Yfit

A named variable that will contain an Npoints-elements vector of calculated values of Y.

Const

A named variable that will contain the constant term.

Sigma

A named variable that will contain the vector of standard deviations for the returned coefficients.

Ftest

A named variable that will contain the value of F for test of fit.

R

A named variable that will contain the vector of linear correlation coefficients.

Rmul

A named variable that will contain the multiple linear correlation coefficient.

Chisq

A named variable that will contain a reduced, weighted, chi-squared.

Status

A named variable that iwll contain the status of the internal array inversion computation.

Keywords

RELATIVE_WEIGHT

If this keyword is set, the input weights (the W vector) are assumed to be relative values, and not based on known uncertainties in the Y vector. Set this keyword in the case of no weighting.