### M Release Notes–-V2.5-9

#### M.1 Modified Commands

The following applications have been modified:

ALIGN2D
• The residuals used to determine the fit are now weighted using the SNR of the data rather than the reciprocal of the variance. This will cause the final alignment to be determined more by the brighter sections of the map than previously.
COLLAPSE
• There is a new estimator option, "FastMed", that offers a substantially faster calculation of unweighted medians.
SETAXIS
• There is a new mode, "NDF". It assigns the axis values using the data values in another NDF, specified by a parameter called AXISNDF.
SQORST
• Has a new Parameter CENTRE, which specifies the centre about which the WCS co-ordinates are stretched or squashed.
WCSALIGN
• The input NDFs can now be aligned with a specified POLPACK catalogue–-see new Parameter REFCAT.
WCSMOSAIC
• Has a new parameter called WEIGHTS that can be used to specify a weight for each of the input NDFs.