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POCalculation - numpy python bug
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copied!<p>I am using NumPy to do some calculation on finding the Y intercept, through an Aperture between a big box and a small box. I have over 100.000 particles in the big box, and around 1000 in the small one. And it's taking a lot of time to do so. All the self.YD, self.XD are very large arrays that i'm multiplying. </p> <p>PS: The ind are indexes of the values that need to be multiplied. I had a nonzero condition before that line in my code. </p> <p>Any ideas how I would do this calculation in a simpler way?</p> <pre><code>YD_zero = self.oldYD[ind] - ((self.oldYD[ind]-self.YD[ind]) * self.oldXD[ind])/(self.oldXD[ind]-self.XD[ind]) </code></pre> <p>Thanks!</p> <p><strong>UPDATE</strong></p> <p>Would using multiply, divide, subtract and all that stuff of Numpy. make it faster? Or if maybe if i split the calculation. for example.</p> <p>to do this first:</p> <pre><code> YD_zero = self.oldYD[ind] - ((self.oldYD[ind]-self.YD[ind])*self.oldXD[ind]) </code></pre> <p>and then the next line would be:</p> <pre><code> YD_zero /= (self.oldXD[ind]-self.XD[ind]) </code></pre> <p>Any suggestions?!</p> <p><strong>UPDATE 2</strong></p> <p>I have been trying to figure this out, in a while now, but not much progress. My concern is that the denominator :</p> <pre><code> self.oldXL[ind]-self.XL[ind] == 0 </code></pre> <p>and I am getting some weird results.</p> <p>The other thing is the nonzero function. I have been testing it for a while now. Could anybody tell me that it is almost the same as find in Matlab</p>

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