Save Parameter Estimates of Linear Regression with by Variable
I am trying to do a linear regression of 2 columns as grouped by a 3rd column and am stuck. I want a column with slope for that row, and another with intercept for that row. Short background: I have 30k different formulations that have each been tested with 13 different levels of an acid. I want to understand the slope of the pH as a function of acid concentration. For my range (and purpose) I c...