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Published on 2010-04-02T12:43:24Z
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2010/04/02
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how can i transpose an 1d array of leading dimension N, without extra space ? any language is fine
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Given a large sparse matrix (say 10k+ by 1M+) I need to find a subset, not necessarily continuous, of the rows and columns that form a dense matrix (all non-zero elements). I want this sub matrix to be as large as possible (not the largest sum, but the largest number of elements) within some aspect…
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I have a "SquareMatrix" template class which inherits "Matrix" template class, like below:
SquareMatrix.h:
#ifndef SQUAREMATRIX_H
#define SQUAREMATRIX_H
#include "Matrix.h"
template <class T> class SquareMatrix : public Matrix<T>
{
public:
T GetDeterminant();
};
template…
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I'm trying figure out how to get an OpenGL specified object to be displayed correctly according to the device orientation (ie. according to the gravity vector from the accelerometer, and heading from compass).
The GLGravity sample project has an example which is almost like this (despite ignoring…
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I'm trying figure out how to get an OpenGL specified object to be displayed correctly according to the device orientation (ie. according to the gravity vector from the accelerometer, and heading from compass).
The GLGravity sample project has an example which is almost like this (despite ignoring…
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Hi
I'm learning templates in C++ so I decied to write matrix class which would be a template class. In Matrix.h file I wrote
#pragma once
#include "stdafx.h"
#include <vector>
using namespace std;
template<class T>
class Matrix
{
public:
Matrix();
~Matrix();
GetDataVector();
…
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I suppose the naive implementation of a + operator for matrices (2D for instance)
in C++ would be:
class Matrix {
Matrix operator+ (Matrix other) const {
Matrix result;
// fill result with *this.data plus other.data
return result;
}
}
so we could use it like
Matrix a;
Matrix…
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What is the best way to scatter a Fortran 90 matrix by its rows rather than columns? That is, let's say I have a matrix a(4,50) and I want to MPI_SCATTER it onto two processes where each part is alocal(2,50), where rank 0 has rows 1 and 2, and rank 1 has 3 and 4. Now, in C, this is simple since arrays…
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I'm working on a project, written in Java, which requires that I build a very large 2-D sparse array. Very sparse, if that makes a difference. Anyway: the most crucial aspect for this application is efficency in terms of time (assume loads of memory, though not nearly so unlimited as to allow me…
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How can I define a array of boost matrices as a member variable?
None of the following worked.
boost::numeric::ublas::matrix arrayM(1, 3)[arraySize];
boost::numeric::ublas::matrix(1, 3) arrayM[arraySize];
boost::numeric::ublas::matrix arrayM[arraySize](1, 3);
Thanks,
Ravi.
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I'm starting to learn about 3D rendering and I've been making good progress. I've picked up a lot regarding matrices and the general operations that can be performed on them.
One thing I'm still not quite following is OpenGL's use of matrices. I see this (and things like it) quite a lot:
x y z…
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