I have two quantitative variables, one with negative and positive values (let's call it A), and the other with solely positive values (let's call it B). I would want to do the correlation between these two variables. These values are those of individuals (one value per individual). I would like to know if this makes sense to correlate directly with the two variables, or to look the correlation between A and B in two groups : one where individuals have negative values for A and the other group where individuals have positive values for A.
Thanks for your help !