What is Lapack: Definition and 14 Discussions

LAPACK ("Linear Algebra Package") is a standard software library for numerical linear algebra. It provides routines for solving systems of linear equations and linear least squares, eigenvalue problems, and singular value decomposition. It also includes routines to implement the associated matrix factorizations such as LU, QR, Cholesky and Schur decomposition. LAPACK was originally written in FORTRAN 77, but moved to Fortran 90 in version 3.2 (2008). The routines handle both real and complex matrices in both single and double precision.
LAPACK was designed as the successor to the linear equations and linear least-squares routines of LINPACK and the eigenvalue routines of EISPACK. LINPACK, written in the 1970s and 1980s, was designed to run on the then-modern vector computers with shared memory. LAPACK, in contrast, was designed to effectively exploit the caches on modern cache-based architectures, and thus can run orders of magnitude faster than LINPACK on such machines, given a well-tuned BLAS implementation. LAPACK has also been extended to run on distributed memory systems in later packages such as ScaLAPACK and PLAPACK.Netlib LAPACK is licensed under a three-clause BSD style license, a permissive free software license with few restrictions.

View More On Wikipedia.org
  1. P

    Linking to LAPACK from g++ in cygwin64

    I get an 'undefined reference to 'zcgesv_'' error when I try to link the LAPACK library using g++ on cygwin64. What am I missing? Google has not turned up anything which solves the problem. (Documentation for zcgesv here ) My Makefile is as follows: GCC := /usr/bin/i686-pc-cygwin-g++ LIBS :=...
  2. G

    Fast pentadiagonal matrix solver

    Hello, I'm currently writing a numerical simulation code for solving 2D steatdy-state heat conduction problems (diffusion equation). After reading and following these two book references (Numerical Heat Transfer and Fluid Flow from Patankar and And Introduction to Computational Fluid Dynamics...
  3. M

    Fortran Fortran Code problems linking to LAPACK library

    Hi, I have a main Fortran code (*.f90) which can calculate eigenvalues and eigenvectors using LAPACK library. Unfortunately, i can't excute this program because i can't link it to the library. I'm using Code Blocks as IDE environment. Any help please.
  4. Telemachus

    Fortran Problem with fortran and lapack

    Hi there. I'm trying to solve a linear system which I have constructed with the aim of learning how to do this in fortran. The idea is to solve: ##A\vec{x}=\vec{b}## The thing is that when I call the subroutine degsv from lapack to solve the linear system, and then write the solution, it only...
  5. Angelos K

    Is LAPACK slow on my system? And if so why?

    I am a programming newbie, I hope I don't give you too much trouble. I use LAPACK on my 2.7GHz CPU. My expectations on the running times are based on Figure 4.1 in this dedicated publication , as well as on Fanfan's answer to this Stackoverflow Post : Both computers mentioned (and especially...
  6. Angelos K

    Cannot use simplest ifstream with LAPACK

    I have an official LAPACK example from here: https://software.intel.com/sites/products/documentation/doclib/mkl_sa/11/mkl_lapack_examples/dsyev_ex.c.htm It compiles and runs without errors or warnings after using ludi@ludi-M17xR4:~/Desktop/tests$ gcc -Ddsyev=dsyev_ -o sylapack sylapack.c...
  7. Angelos K

    LAPACK dgeev: parameter had illegal value

    Mod note: I revised the code below slightly, changing the loop control variable i to either j or k. The reason for this is that the browser mistakes the letter i in brackets for the BBCode italics tag, which causes some array expressions to partially disappear. Hello, I am trying for the first...
  8. B

    Fortran [Fortran] Problems with LAPACK routine

    I am trying to use the LAPACK routine dsyev to solve for the eigenvalues of a matrix, and I designed a program to test this and make sure I am getting the right results. It isn't recognizing the subroutine however. The subroutine is dsyev, which I can post or can be found on the LAPACK site...
  9. T

    Fortran How can I successfully use the LAPACK package with gfortran on windows?

    Hi, I've been using gfortran on windows through the command line to compile .f95 files using the command gfortran file.f95 to get an a.exe file which I can then run. However, I'm currently writing some Fortran code which needs some of the subroutines of the LAPACK package. I've been...
  10. D

    Makefile library issues: gsl and lapack

    I don't have all of the info at my finger tips because I had to come to work and leave my comp at home, but here is my issue and I can post extra info if anyone has questions: I am working with a professor who has me running his code (C++) that links to gsl and lapack. Specifically, the code...
  11. T

    Fortran Solving the Fortran LAPACK DSYEV Error with a 3x3 Matrix

    Hello I am a beginner in programming with Fortran and I want to use the LAPACK DSYEV in my program. I am an example to determine the eigenvalues ​​of a matrix (3x3) after I use it in my program but when I compile I get this error "" "" "** One entry to DSYEV parameter number 5 Had an illegal...
  12. T

    Fortran Solving Fortran Lapack Compilation Issues

    Can you please help me I can't compile using lapack libraries and I can't find anyone who can tell me how to compile. I have blas_LINUX.a and lapack_LINUX.a and I am trying to use ifort to compile my program but I always get the below error. Please help. These are the libraries I have in...
  13. C

    Fortran Strange results using dgesv (lapack) via fortran 90

    Hello all, I am trying to learn fortran 90 by rewriting some simple MATLAB codes I have in fortran. I tried to rewrite a linear, 1D finite element code for an elliptic equation and my fortran and MATLAB codes both end up assembling the same system matrixes (K and f), but the solution to...
  14. B

    LAPACK for Fortran under Cygwin

    I just installed LAPACK, but I'm not sure how to use it. The documentation tells about the routines, but the problem is my compiler isn't recognizing them. For example...I wrote a simple Fortran program to test a routine (SGESV): program testlapack implicit none...