lib/linefit.rb
############################################################################
# Return the estimated homoscedastic standard deviation of the
# error term
#
# sigma = linefit.sigma
#
# Sigma is an estimate of the homoscedastic standard deviation of the
# error. Sigma is also known as the standard error of the estimate.
#
# The return value is undefined if the regression fails. If weights are
# input, the return value is the weighted standard error.
#
Return the estimated homoscedastic standard deviation of the
error term



Sigma is an estimate of the homoscedastic standard deviation of the
error. Sigma is also known as the standard error of the estimate.

The return value is undefined if the regression fails. If weights are
input, the return value is the weighted standard error.
Return the estimated homoscedastic standard deviation of the error term Sigma is an estimate of the homoscedastic standard deviation of the error . Sigma is also known as the standard error of the estimate . The return value is undefined if the regression fails . If weights are input the return value is the weighted standard error .
def sigma
      unless @sigma
         self.regress or return
         @sigma = @numxy > 2 ? Math.sqrt(sumSqErrors() / (@numxy - 2)) : 0
      end
      return @sigma
   end
def sigma unless @sigma self . regress or return @sigma = @numxy > 2 ? Math . sqrt ( sumSqErrors ( ) / ( @numxy - 2 ) ) : 0 end return @sigma end
Return the estimated homoscedastic standard deviation of the
error term
Return the estimated homoscedastic standard deviation of the error term