
Get the median absolute deviation (MAD) of the column in the selected Table (adjusted by a scale factor).
From the n numbers x_{1}, x_{2}, ..., x_{n} in the selected column we first calculate the median value x_{median}. Next we calculate the n absolute deviations from this median: d_{1}, d_{2}, ..., d_{n}, where d_{j}=x_{j}  x_{median}. Then we calculate the MAD value, which is the median of the n values d_{1}, d_{2}, ..., d_{n}. Finally we multiply the MAD value by the scale factor 1.4826. This last multiplication makes the result comparable with the value of the standard deviation if the x values are normally distributed.
© djmw, April 5, 2012