Questions tagged [elementwise-operations]
204 questions
3
votes
2 answers
Multiply elements of a matrix with vector values
I have a matrix M, I want to create 3 additional matrices where each additional matrix has certain 3x3 column-slices of M multiplied by values in a vector, I will then store the resulting 3 new matrices in a list.
##create the initial matrix
M <-…
flee
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3
votes
3 answers
How to apply one argument to Array{Function, 1} element-wise smartly in Julia?
I understand Julia can apply element-wise argument to a function by f.(x)
in v0.6
x = [1, 2, 3]
f = x->3x
@assert f.(x) = [3, 6, 9]
Now, I define f as Array{Function, 1}.
f1(x) = 3x
f2(x) = 4x
f = [f1, f2]
x = 2
@assert isa(f, Array{Function,1})…
Hiroaki
- 47
- 4
3
votes
2 answers
Creating an array in Swift by applying binary operation to all elements of two other arrays
Is there a concise way in Swift of creating an array by applying a binary operation on the elements of two other arrays?
For example:
let a = [1, 2, 3]
let b = [4, 5, 6]
let c = (0..<3).map{a[$0]+b[$0]} // c = [5, 7, 9]
Danra
- 9,546
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3
votes
1 answer
Numpy element-wise in operation
Suppose I have a column vector y with length n, and I have a matrix X of size n*m. I want to check for each element i in y, whether the element is in the corresponding row in X. What is the most efficient way of doing this?
For example:
y =…
zycuber
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- 7
3
votes
2 answers
How to efficiently construct a matrix in matlab that depends on indices
In my program in matlab I have several instances where I need to create a matrix, which entries depends on its indices and perform matrix-vector operations with it. I wonder how I can implement this most efficiently.
For example, I need to speed…
Optimist
- 131
- 4
3
votes
0 answers
Python: How to divide row values in csv file with respect to assigned specific values?
I would like do perform division with respect to its alphabet. Given an example as below:
The binary file given is in csv format:
A=1000, C=0100, G=0010, T=0001
binary.csv: CAT, GAA
0,1,0,0,1,0,0,0,0,0,0,1
0,0,1,0,1,0,0,0,1,0,0,0
The binary.csv…
Xiong89
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3
votes
2 answers
Apply function to each row in Torch
I know that tensors have an apply method, but this only applies a function to each element. Is there an elegant way to do row-wise operations? For example, can I multiply each row by a different value?
Say
A =
1 2 3
4 5 6
7 8 9
and
B =
1
…
Veech
- 1,397
- 2
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2
votes
1 answer
Elementwise substraction in Julia
I am comming to julia from MATLAB and find myself startled at the idea that there isnt a better way to solve this: 1-[.5 .2 1] in julia does not compute to [0.5 0.8 0]
1-[.5 .2 1] MATLAB-> [0.5 0.8 0]
While in julia the best I got is:
-(-[.5 .2…
Orlando
- 23
- 3
2
votes
3 answers
Can jq add objects in two JSON object lists sequentially?
I am seeking the simultaneous iteration of two lists.
Input object list:
First Input Object List
{
"k11": "v111",
"k12": "v112"
}
{
"k11": "v121",
"k12": "v122"
}
{
"k11": "v131",
"k12": "v132"
}
Second Input Object List
{
"k21":…
Paul
- 442
- 4
- 9
2
votes
0 answers
Numpy: Why is elementwise binary operation much slower when applied to matrixes with inconsistent memory layout and sizes being big powers of 2?
I have been experimenting with performance of operation in Numpy and it turns out that performing element-wise operation (for example np.multiply) on matrices with inconsistent memory layout (one with order 'C' and second 'F') is around 2 times…
krzysztor
- 21
- 5
2
votes
2 answers
Matrix multiplication with vector based on another matrix in R
I need to multiply one matrix with one conditional vector, to get a vector of solutions, based on another matrix.
# Matrix A
lsA <- c(1,1,0,1,1,2,1,0,1,2,1,1,0,0,1,1,0,0,0,1)
A <- matrix(lsA,4,5, byrow = T)
# Matrix B
ls <-…
ana_gg
- 370
- 1
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2
votes
2 answers
elementwise comparison in ndarray::Array1 in rust
I'm trying to find the rust equivalent of this python numpy code doing elementwise comparison of an array.
import numpy as np
np.arange(3) > 1
Here's my rust code:
use ndarray::Array1;
fn main() {
let arr = Array1::::range(0.0, 3.0, 1.0);
…
Chad
- 1,434
- 1
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- 30
2
votes
1 answer
Pandas: Element-wise sum-product of data frame of values using a another data frame containing row weights
Hopefully, this is not a duplicate. I have two data frames: The first data frame has size n x m, and each cell contains a list of numeric values of size k. The second data frame has size n x k, and each cell contains a single numeric value…
rhozzy
- 332
- 1
- 9
2
votes
2 answers
Element-wise operation with lambda (pd.DataFrame)
Trying to subtract a constant array from a DatraFrame using lambda.
This is my DataFrame d:
import pandas as pd
d = pd.DataFrame()
d['x'] = pd.Series([1, 2, 3, 4, 5, 6])
d['y'] = pd.Series([11, 22, 33, 44, 55, 66])
A working as expected classical…
Lourenco
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2
votes
3 answers
Java Element-wise merge of two list
I have two List of int like {1,2,3} and {4,5,6}.
I need to obtain a List> like:
((1,4),(2,5),(3,6))
How should i proceed? I tried with for but i can get only the cartesian product
pierbin24
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