Oops!! My bad.. I did a reply and not a reply all... Anyways Thanks David.. I knew this wasn't really a bug but could not figure out where to post my questions. Let me just try the same in a different way or do it differently as you explained and see if I can make it to work.
Thanks On Tue, Sep 15, 2015 at 12:33 AM, David G. Johnston < david.g.johns...@gmail.com> wrote: > Oh, and don't reply to people individually. I'm going to move this to > -general with one last copy for -bugs even though it is not one. > > On Mon, Sep 14, 2015 at 3:01 PM, David G. Johnston < > david.g.johns...@gmail.com> wrote: > >> On Mon, Sep 14, 2015 at 2:55 PM, Biswadeep Banerjee < >> biswadeep.baner...@actifio.com> wrote: >> >>> Hi David, >>> May be I gave a wrong example to explain my issue. >>> >>> Below is a sample query that I have been trying to get the slope and >>> intercept. The inner query basically gives me the time vs capacity, ie. x >>> and y data showing the actuals. Based on the x, y value, I calculate slope >>> and intercept value, as in the outer query. >>> >>> But it looks like am back to your comment as it mentions I am asking for >>> slope and intercept of a single point. Could you provide me some examples >>> that I can use as a reference. >>> As a reference, I am following similar example as in >>> http://stackoverflow.com/questions/20490756/linear-regression-with-postgres >>> >>> select x, y, regr_slope(y,x), regr_intercept(y,x) >>> from ( >>> /* doesn't matter */ >>> >>> ) i >>> group by x, y >>> order by x asc, y asc >>> >> >> You are grouping on (x, y) >> >> and then passing this single POINT into a function that requires >> multiple points in order to calculate the slope and intercept of a LINE >> (i.e., something requiring two points to describe) and are confused why it >> is giving you NULL... >> >> I have answered your question - you are using the functions incorrectly. >> >> This is operator error, not a bug. >> >> You have already found a reasonably good example of how these functions >> can be used. Given I have never used them myself I do not have anything >> better to offer. >> >> David J. >> >> >> > > -- Best Regards, Biswadeep Banerjee
