• + 3 comments

    I don't see why this isn't 0.96, I get the angle as 16.26 with a cos of 0.96.

    • + 0 comments

      Yeah, actually I don't have a clue of correlation of regression. cosine similarity is not the case perhaps, but...

    • + 1 comment

      You're assuming that the data has been centered.

      • + 1 comment

        So, this code gives -0.68, which is wrong.

        #!/usr/bin/python import random,scipy.stats

        x=[] y=[] for _ in range(1000000): z=random.random() x.append(z) y.append((-3*z-8)/4.0) for _ in range(1000000): z=random.random() x.append(z) y.append((-4*z-7)/3.0)

        a,b = scipy.stats.pearsonr(x,y) print('%.2f'%(a))

        • + 1 comment

          Eh, so, I was able to solve this problem.

          When scipy.stats.linregress(x,y)[0] and scipy.stats.linregress(y,x)[0] are both -0.75, answer scipy.stats.pearsonr(x,y)[0].

          The problem statement is too difficult to understand...

          • + 0 comments

            I just get error when I submit the code and prints nothing when I run the code. Of course I have populated the x and y lists, tried your random population method too, but nothing. Any thoughts thanks a lot

            a,b = scipy.stats.pearsonr(x,y) print('%.2f'%(a))

    • + 0 comments

      For centered data the correlation coefficient is the cosine of the angle, but for un-centered data, it's the secant minus the tangent. [1]

      I get the wrong sign when I do it that way, though.