Top "Matrix" questions

How to create an empty matrix in R?

I am new to R. I want to fill in an empty matrix with the results of my for loop …

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Numpy matrix to array

I am using numpy. I have a matrix with 1 column and N rows and I want to get an array …

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Vector of Vectors to create matrix

I am trying to take in an input for the dimensions of a 2D matrix. And then use user input …

c++ vector matrix

Apply a function to every row of a matrix or a data frame

Suppose I have a n by 2 matrix and a function that takes a 2-vector as one of its arguments. I …

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How to get element-wise matrix multiplication (Hadamard product) in numpy?

I have two matrices a = np.matrix([[1,2], [3,4]]) b = np.matrix([[5,6], [7,8]]) and I want to get the element-wise product, [[1*5,2*6], [3*7,4*8]], equaling [[5,12], [21,32]] I …

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What does the error "arguments imply differing number of rows: x, y" mean?

I'm trying to create a plot from elements of csv file which looks like this: h1,h2,h3,h4 a,1,0,1,0 …

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how does multiplication differ for NumPy Matrix vs Array classes?

The numpy docs recommend using array instead of matrix for working with matrices. However, unlike octave (which I was using …

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Convert a matrix to a 1 dimensional array

I have a matrix (32X48). How can I convert the matrix into a single dimensional array?

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Inverse of a matrix using numpy

I'd like to use numpy to calculate the inverse. But I'm getting an error: 'numpy.ndarry' object has no attribute …

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java Arrays.sort 2d array

I am looking to sort the following array based on the values of [][0] double[][] myArr = new double[mySize][2]; so for …

java arrays sorting matrix