[SciPy-User] Scipy dblquad Calculation

Scott Barlow Spectre158@gmail....
Wed Feb 24 19:48:36 CST 2010

Warren Weckesser <warren.weckesser <at> enthought.com> writes:
> Scott,
> As you suspected, the problem is your use of arctan, and an appropriate 
> use of arctan2 can correct it.  If I change this:
>                            t*scipy.sin(theta + 
> scipy.arctan((a**2.0/b**2.0)*(1.0/scipy.tan(theta))))
> to this:
>                            t*scipy.sin(theta + scipy.arctan2( 
> a**2.0*scipy.cos(theta), b**2.0*scipy.sin(theta)) )
> then the results agree.
> Warren

Ah, excellent.  Thank you very much for your help Warren!  When I tried using
arctan2, I didn't think about breaking up tangent into its sine and cosine
components and instead kept it as tangent or cotangent in the numerator or
denominator, as appropriate.


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