The statistics step in Pentaho PDI computes the mean and standard deviation but does not include a calculation for z-score

I tried to do it by using the statistics step to compute the mean and standard deviation of a field and then feed the input file through again calculating the z-score by subtracting the mean of the field from the value of the field, divided by the standard deviation.

I need to compute the z-score for several fields in a file. I then need to write out the file including the z-score of those fields.

But how do you put two inputs into one step? I need to put the data file in but I also need to put the statistics in too (the mean and standard deviation) in the same step to compute the z-score.

I know you can put multiple files (for example, csv file) to be read into one step but all the files must have the same format

How does one read in, two different files, into a Transformation step?

Thanks for help!