NAME: meanerr2 PURPOSE: (one line) Calculate the mean and estimated error for a set of weighted data points DESCRIPTION: This routine is adapted from Program 5-1, XFIT, from "Data Reduction and Error Analysis for the Physical Sciences", p. 76, by Philip R. Bevington, McGraw Hill. This routine computes the weighted mean using Instrumental weights (w=1/sigma^2). The final uncertainty is insensitive to a multiplicative constant on the weights. CATEGORY: Statistics CALLING SEQUENCE: meanerr2,x,weight,xmean,xsigma INPUTS: x - Array of data points weight - array of weights for data points OPTIONAL INPUT PARAMETERS: None. KEYWORD PARAMETERS: None. OUTPUTS: xmean - weighted mean xsigma - uncertainty of xmean COMMON BLOCKS: None. SIDE EFFECTS: None. RESTRICTIONS: None. PROCEDURE: MODIFICATION HISTORY: Written by Marc W. Buie, Lowell Observatory, 2000/10/01 2000/10/3, MWB, mostly WMG, it now works.