[Numpy-discussion] Sum of the product of three or more arrays

Robert Kern robert.kern@gmail....
Thu Oct 18 18:08:06 CDT 2007


Geoffrey Zhu wrote:
> Hi All,
> 
> Given three vectors of the same lengths, X, Y, and Z, I am looking for
> an efficient way to calculate the following:
> 
> sum(x[i]*y[i]*z[i], for i=1..n )

(x*y*z).sum()

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco


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