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Questions tagged [lapacke]

a C interface to LAPACK, a FORTRAN software library for linear algebra

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difference between lapacke and lapack

I wonder what is the difference between LAPACKE and LAPACK. I want to do Eigen analysis with QZ decomposition, but I'm not sure if I should start with LAPACKE or LAPACK. I appreciate any help.
Megidd
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LAPACK/LAPACKE with C++ on LINUX --- Compiling, Linking and Running?

Intro: I've developed an application in C++ that utilizes LAPACK(LAPACKE) and MPI, all on Windows. Works OK in Windows (compiling and linking are taken care of through Code::Blocks IDE), but the execution is way too slow. Hence, I want to migrate…
Boki
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understanding Lapack_row_major and Lapack_col_major with lda

I have three questions regarding lapack_row_major and lapack_col_major: 1) Is my understanding correct that if A = [1,2,3,4,5,6] with dimensions 2*3 then the lapack_row_major results in [ [1,2,3],[4,5,6] ], while lapack_col_major results in […
Mina
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errors using lapack C header in C++ with visual studio 2010

Please help me! It takes me hours to look up in the internet and I haven't found a solution.... I am trying to use the call lapack function from C++ functions but I failed at the very beginning. Here is my code: #include "stdafx.h" #include…
Jason
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What is the use of the WORK parameters in LAPACK routines?

I am computing an eigenvalue decomposition of a symmetric matrix with scipy.linalg.cython_lapack.syev. From the doc I found, I need to pass an array called WORK: WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)) On exit, if INFO…
P. Camilleri
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Differing Results Of Eigenvector Routines In C Versus Python

So I noticed that I get different answers for the eigendecomposition of the 4x4 matrix of all 1s. In Python using numpy.linalg.eig: matrix = numpy.ones((M,M), dtype=float); values, vectors = numpy.linalg.eig(matrix); Python Result: V1: [-0.866025…
The Dude
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LAPACKE or MAGMA GPU - inversion of matrix with Cholesky factorization - functions magma_dpotrf_gpu and magma_dpotri_gpu

I have a first version of a function that inverses a matrix of size m and using magma_dgetrf_gpu and magma_dgetri_gpulike this : // Inversion magma_dgetrf_gpu( m, m, d_a, m, piv, &info); magma_dgetri_gpu( m, d_a, m, piv, dwork, ldwork,…
user1773603
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How to use OpenBlas Lapacke together with Rcpp

I have some running c++ code using the Lapacke version that comes with OpenBlas. I would like to include this code into an R package and transfer data between that function and R using the Rcpp package. But somehow the two seem not to like each…
Alex
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Using OpenBLAS LAPACKE in Visual Studio

i need some linear algebra in my project and want use OpenBLAS for this. I downloaded the precompiled version (64bit version) and unpacked it to my projectfolder. In Visual Studio, i added include-, bin-, and lib-folder to my Project and ran the…
Thorsten Schmitz
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LAPACK zgemm op(A) dimension

In this link from netlib it specifies M as: On entry, M specifies the number of rows of the matrix op( A ) and of the matrix C. M must be at least zero. Unchanged on exit. So if I want to use a 3x10 matrix as…
Alireza
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FindBLAS and FindLAPACK usage in CMake

I am a bit confused by the utility of find_package(BLAS) and find_package( LAPACK) within CMake. It seems that depending on the vendor found, different source code is necessary. For example, mkl has mkl.h and/or mkl_lapacke.h but at least one…
rhl
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How to allocate the memory for b in LAPACK sgelsd routine

According to the official user guide line, sgelsd is used to solve the least square problem min_x || b - Ax ||_2 and allows matrix A to be rectangle and rank-deficient. And according to the interface description in the sgelsd source code, b is used…
coinsyx
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Compute generalized eigenvalue problem with CLapack in C

I'm going to show you an example how to compute generalized eigenvalue problem in C with CLapack. Here I have two matrices. #define row 5 #define column 5 float A[row * column] = { 9.5605, 6.8163, - 1.9425, - 5.7558, 3.5550, 0.8163, …
euraad
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Compiling LAPACKe library using C in MacOS

I need to use LAPACKe functions in a code that should run on Linux and macOS, but the problem is under OsX. I have a MacBook Pro 2021, with an M1 Pro processor, running an OsX 12.6.2 I wrote an example code #include #include…
Or1on
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LAPACKE_dsyevd returns wrong eigenvectors

I am very far from being a great programmer and I am trying to use LAPACKE_dsyevd. I wrote the following code which aims to find out the eigenvalues and eigenvectors of a 2x2 symmetric matrix whose diagonal is made of 0 and non diagonal elements are…
Philippe Michelon
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