SigmaY Imports a three-columned text file into MPL Fitting. The first column must be the X values, the second column must be the Y values and the third column must be the SigmaY values.
More information is given below for a particular type of fit.
The user is asked to enter a value for every X error bar in the data set. They may either choose a particular value, choose not to have X error bars on the data set, or cancel the import process.