All Questions
11 questions
1
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0
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148
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Does cblas_dgemm mutate my input matrices?
I have written a matrix class Matrix<T> for which I have implemented a wrapper function for cblas_dgemm.
...
- 111
2
votes
1
answer
4k
views
LAPACK equivalent on c++ , which is the best one? [duplicate]
I am following a course of computational material physics. The professor uses fortran to code and uses lapack to solve eigenvalue problems.
So far I just know c++. There is an equivalent library that ...
- 21
0
votes
2
answers
2k
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Does armadillo library slow down the execution of matrix operations?
I've converted a MATLAB code to C++ to speed it up, using the Armadillo library to handle matrix operations in C++, but surprisingly it is 10 times slower than the MATLAB code!
So I test the ...
- 131
1
vote
1
answer
477
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C++: Efficient library for dense linear algebra operations (determinant & principal minors)
I usually work with Python, but my basic knowledge of c++ allows me to switch when I need to increase the speed of my code.
Currently, I have a python script that (among other things) computes the ...
- 113
0
votes
1
answer
484
views
How to do a Generalized Complex Schur (or QZ) Decomposition with Eigen C++? [closed]
I would like to do a Generalized Schur (or QZ) decomposition for a pair of complex matrices $A$ and $B$.
I found the following class:
...
- 101
1
vote
1
answer
990
views
LAPACK sorting eigenvalues differently each time
I'm using LAPACK zgeev routine to get eigenvalues and eigenvectors of a symmetric matrix in C++. Problem is zgeev is being called in a loop but it sorts eigenvalues (and eigenvectors) differently ...
- 313
0
votes
2
answers
524
views
Matlab, Mathematica & LAPACK returning 3 different eigenvectors
(I'm not sure which of math.se / stackoverflow / scicomp.se is the right place to ask this question)
I have a C++ code which generates a complex matrix and then calculates its eigenvalues and ...
- 313
2
votes
0
answers
78
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Under what circumstances does Elemental's distributed SVD not work? [closed]
I am playing around with Elemental's distributed singular value decomposition and am running into two particular issues.
Building the test at tests/lapack_like/SVD.cpp, and running with
...
- 21
1
vote
1
answer
80
views
LAPACK DGGEVX: BALANC option
I'm using DGGEVX routine from LAPACKE with BALANC option as shown below, but to my surprise changing BALANC option from 'N' to ...
- 165
2
votes
0
answers
137
views
Lapack++ for QR algorithm
I have recently started using Lapack++ which I found convenient for my programming purpose, in general.
Now, I need to solve a matrix using QR algorithm. I've searched the user manual
and I found a ...
15
votes
2
answers
9k
views
solve $xA=b$ for $x$ using LAPACK and BLAS
I am porting an existing code from MATLAB to C++ and have a linear system to solve $xA=b$ (rather than the more typical form $Ax=b$)
The matrix $A$ is dense, and of general form, but is no larger ...
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