code for coefficient of determination

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code for coefficient of determination

Postby somayeh3333 » Sat Nov 02, 2013 11:22 pm

I am trying to define a function to compute the coefficient of determination.here is what I have done so far.I appreciate any help to know what I am doing wrong

Code: Select all
def r2( y, f ) :
    from numpy import mean                            # importing required libraries
    from cmath import sqrt
    n = len(y)
    ybar = mean(y)                                 # mean of y
    sigma_y^2 = (1.0/n)*sum((y-ybar)**2)    # variance of y
    m = (mean(x*y)-(mean(x)*mean(y)))/(mean(x**2)-(mean(x)**2))
    b = mean(y) - m*mean(x)
    f = m*x + b
    sigma_f^2 = (1.0/n)*sum((f-y)**2)
    R^2 = 1 - (sigma_f^2/sigma_y^2)
    return R^2
Last edited by stranac on Sat Nov 02, 2013 11:42 pm, edited 1 time in total.
Reason: Added code tags. Locked.
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Re: code for coefficient of determination

Postby micseydel » Sun Nov 03, 2013 10:23 pm

You should read this and then provide more information that would help us to help you.
Join the #python-forum IRC channel on irc.freenode.net!
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Re: code for coefficient of determination

Postby ochichinyezaboombwa » Wed Nov 06, 2013 4:08 am

Code: Select all
sigma_y^2 = ...
R^2 = ...
are not Python. Also, I don't think mean(x*y) works at all (and if it does I'd be surprised if it does what you want).

In other words: you cannot "translate" any formula to what you think it should look like in Python. You need to know at least some language before trying to write in it.
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