  C RUBY-ON-RAILS MYSQL ASP.NET DEVELOPMENT RUBY .NET LINUX SQL-SERVER REGEX WINDOWS ALGORITHM ECLIPSE VISUAL-STUDIO STRING SVN PERFORMANCE APACHE-FLEX UNIT-TESTING SECURITY LINQ UNIX MATH EMAIL OOP LANGUAGE-AGNOSTIC VB6 MSBUILD # matrix addition from an array r ## matrix addition from an array r Tag : arrays , By : firebasket Date : November 29 2020, 09:01 AM

help you fix your problem Here is code which loops a number of times (272) and adds a matrix to the same list.
``````B <- matrix(c(0,0,0,0),nrow = 2)
list <- list(B)
for (i in 2:272) {
list[[i]] <- B
}
``````
``````sum <- Reduce('+', list)
> sum
[,1] [,2]
[1,]    0    0
[2,]    0    0
`````` Boards Message : You Must Login Or Sign Up to Add Your Comments .

## Javascript matrix addition of an arbitrary number of arrays' values, without using array.map()

Tag : javascript , By : oiyto
Date : March 29 2020, 07:55 AM
will help you No need for map, you only need to keep track of the arrays as you total them.
(This does not check that the arrays have the same length-)
``````  function sumArrayElements(){
var arrays= arguments, results= [],
count= arrays.length, L= arrays.length,
sum, next= 0, i;
while(next<count){
sum= 0, i= 0;
while(i<L){
sum+= Number(arrays[i++][next]);
}
results[next++]= sum;
}
return results;
}

var a= [1, 2, 3], b= [4, 5, 6], c= [1, 2, 3];
sumArrayElements(a, b, c)
/* returned value:(Array)
6, 9, 12
*/
``````

## Program crashes at: (1) matrix multiplication; and (2) failed matrix addition/subtraction

Tag : cpp , By : dexteryy
Date : March 29 2020, 07:55 AM
this will help You posted a copy constructor and assignment operator. Your assignment operator has 4 major issues:
You should pass the parameter by const reference, not by value. You should return a reference to the current object, not a brand new object. If new throws an exception during assignment, you've messed up your object by deleting the memory beforehand. It is redundant. The same code appears in your copy constructor.
``````#include <algorithm>
//...
Matrix& Matrix::operator=(const Matrix& aMatrix)
{
Matrix temp(aMatrix);
swap(*this, temp);
return *this;
}

void Matrix::swap(Matrix& left, Matrix& right)
{
std::swap(left.rows, right.rows);
std::swap(left.cols, right.cols);
std::swap(left.element, right.element);
}
``````
``````Matrix& Matrix::operator+=(const Matrix &aMatrix)
{
if(rows != aMatrix.rows || cols != aMatrix.cols)
throw SomeException;
for(int i = 0; i < rows; i++)
{
for(int x = 0; x < cols; x++)
element[i][x] += aMatrix.element[i][x];
}
return *this;
}

Matrix Matrix::operator+(const Matrix &aMatrix)
{
Matrix temp(*this);
temp += aMatrix;
return temp;
}
``````

## Sparse Matrix Addition yields 'ValueError: setting an array element with a sequence.'

Tag : python , By : Sharad
Date : March 29 2020, 07:55 AM
To fix the issue you can do The lines in question are: , The problem is that
``````(dmat.T.dot(sparse.spdiags(w*peq[idx_s:idx_e], 0, Np, Np)).dot(dmat)
``````
``````dmat.T.dot(sparse.spdiags(w*peq[idx_s:idx_e], 0, Np, Np).A).dot(dmat)
``````
``````sparse.spdiags(...).dot(dmat etc)
``````

## Confused myself with matrix and array addition

Tag : python , By : Waynew
Date : March 29 2020, 07:55 AM
I hope this helps you . When using standard lists, addition is defined as concatenation of the two lists
``````import numpy as np

list1 = [1,2,3,4]
list2 = [2,3,4,5]

print list1 + list2
# [1, 2, 3, 4, 2, 3, 4, 5]
``````
``````array1 = np.array(list1)
array2 = np.array(list2)

print array1 + array2
# [3 5 7 9]
``````

## Ruby matrix addition to multi dimensional array

Tag : python , By : Maplye
Date : March 29 2020, 07:55 AM 