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Questions tagged [vector-multiplication]

46 questions
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Vectorized multiplication: Multiply two vectors in Julia, element-wise

I decided to dive into Julia and hitting the wall; fast. I am trying to replicate a simple operation, which would like as follows in python numpy a = numpy.array([1,2,3]) b = numpy.array([1,2,3]) a*b [output]: [1,4,9] In other words "[1,4,9]" is…
dmeu
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Convert values of a tensor in TensorFlow to regular Javascript array

I used the outerProduct function in the TensorFlow.js framework on two 1D arrays (a,b), but I am finding it difficult to get the values of the resulting tensor in the regular javascript format. Even after using .dataSync and Array.from(), I am…
Isaac
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Why am I getting two different answers with quaternion-vector multiplication

I am trying to multiply a quaternion with a vector following the formula q * v * q_conjugate(q) I found in this thread. When I run the following code in Python, I get an output that looks correct. However, when I run the code again I get another…
Frederik Petri
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Is numpy.multiply always equivalent to the * operator?

The numpy.multiply documentation says: Equivalent to x1 * x2 in terms of array broadcasting. Is np.multiply(x1, x2) different to x1 * x2 in any circumstance? Where would I find the implementations of each? Note: An analogous question exists for…
Tom Hale
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Vector Multiplication using GPU on python

I'm trying to do vector multiplication using numba vectorize. But instead of having two lists containing int or float type, i have two lists containing objects. I want to do multiplication of the attributes contained in these objects. ie. ob1.attr *…
SunshineAndLove
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MATLAB: element-wise multiplication of two matrices over one index?

I'm trying to figure out if there's a native way of obtaining a certain kind of element-wise product of two matrices in Matlab. The product that I'm looking for takes two matrices, A and B say, and returns there product C, whose elements are given…
Kris
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Multiply rows of matrix by vector elementwise in pytorch?

I would like to do the below but using PyTorch. The below example and description is from this post. I have a numeric matrix with 25 columns and 23 rows, and a vector of length 25. How can I multiply each row of the matrix by the vector without…
avgJoe
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Return double from vector multiplication with Armadillo C++

Do you know why I cannot store in a double the result from a vector multiplication ? double A = rowvec({1,3,4})*vec({5,6,7}); It gives "no suitable conversion function from "const arma::Glue"... to "const double" exists. Still that matrix vector…
user6581106
2
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1 answer

Matrix-Vector and Matrix-Matrix multiplication using SSE

I need to write matrix-vector and matrix-matrix multiplication functions but I cannot wrap my head around SSE commands. The dimensions of matrices and vectors are always multiples of 4. I managed to write the vector-vector multiplication function…
Denis Yakovenko
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Multiplying numbers in a list (coordinate-wise) without using mapcar in Lisp

I'm having trouble with the output of my code, I think it's when I'm checking conditions for the null of my lists. The question I am trying to complete is: Write a function vecmul that will take as inputs two simple lists of numbers. vecmul should…
DLR
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How to execute the cross multiplication in unittest

I have the following class from math import sqrt class Vector: def __init__(self, x, y, z): self.x = x self.y = y self.z = z def __eq__(self, other): # v == w return self.x == other.x and self.y == other.y and…
12666727b9
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Create a long list where each element of one list is repeated/ multiplied by a value from another dataframe

I have run into a bit of a conundrum that I can't find any obvious answers to on stack overflow, so wondered if I could please pick the expertise hive mind! I basically have a list of providers, which I have grouped by region to get the number of…
KatChristiansen
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Vector math arithmetic operations in jq

I'd like to perform vector math operations on a json array that stores numbers. In short how can we achieve one to one arithmetic operations by using jq? I tried something with 'map' filter however could not achieved what I expect. jq…
Hüseyin
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Multiplying 2 arrays into a 3rd blank array range VBA(Excel)

Dim i As Integer, q As Integer Dim rng As Range Dim my_array1elm Dim my_array2elm Dim x As Long Sub Yoo() Range("B1").Select For i = 1 To 12 ActiveCell.Value = i ActiveCell.Offset(0, 1).Select Next Range("A2").Select For q = 1 To 12 …
robin hood
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Python pair-wise multiplication using broadcasting on the first dimension

I have one-hot vector of shape 1 * n v= [0.0, 1.0, 0.0] for n = 3 and a matrix of shape n * m * r as( m and r can be any number but the first dimention is as n) m = [[[1,2,3,],[4,5,6]], [[5,6,7],[7,8,9]], [[2,4,7],[1,8,9]]] I want to multiple a *…
Mahmood
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