lapack

lapack/blas/openblas proper installation from source - replace system libraries with new ones

对着背影说爱祢 提交于 2019-12-05 17:51:59
I wanted to install BLAS, CBLAS, LAPACK and OpenBLAS libraries from source using available packages you can download here openblas and lapack , blas/cblas . Firstly I removed my system blas/cblas and lapack libraries, but unfortunately atlas library couldn't be uninstalled (I can either have both blas and lapack or atlas - can't remove them all). I didn't bother and started compiling downloaded libraries cause I thought that after installation I would be able to remove atlas. Building process was based on this tutorial. For completeness I will list the steps: OpenBLAS . After editing Makefile

Docker images with architecture optimisation?

拥有回忆 提交于 2019-12-05 17:30:39
Some libraries such as BLAS/LAPACK or certain optimisation libraries get optimised for the local machine architecture upon compilation time. Lets take OpenBlas as an example. There exist two ways to create a Docker container with OpenBlas: Use a Dockerfile in which you specify a git clone of the OpenBlas library together with all necessary compilation flags and build commands. Pull and run someone else's image of Ubuntu + OpenBlas from the Docker Hub. Option (1) guarantees that OpenBlas is build and optimised for your machine. What about option (2)? As a Docker novice, I see images as

Is integer multiplication implemented using double precision floating point exact up until 2^53?

隐身守侯 提交于 2019-12-05 00:30:31
问题 I ask because I am computing matrix multiplications where all the matrix values are integers. I'd like to use LAPACK so that I get fast code that is correct. Will two large integers (whose product is less than 2^53 ), stored as double s, when multiplied, yield a double containing the exact integer result? 回答1: Your analysis is correct: All integers between -2 53 and 2 53 are exactly representable in double precision. The IEEE754 standard requires calculations to be performed exactly, and then

Installing BLAS on a mac OS X Yosemite

不想你离开。 提交于 2019-12-04 23:43:21
问题 I'm trying to Install BLAS on my Mac, but every time I run make I get this error (shown below the link). I was trying to follow the instructions on this website: gfortran -O3 -c isamax.f -o isamax.o make: gfortran: No such file or directory make: *** [isamax.o] Error 1 I have no idea what this means or how to fix it so any help would be appreciated. Also I'm trying to install CBLAS and LAPACK so any tips/instructions for that would be nice if you know of a good source...Everything I've found

Symmetric Matrix Inversion in C using CBLAS/LAPACK

余生长醉 提交于 2019-12-04 16:17:29
I am writing an algorithm in C that requires Matrix and Vector multiplications. I have a matrix Q (W x W) which is created by multiplying the transpose of a vector J (1 x W) with itself and adding Identity matrix I , scaled using scalar a . Q = [(J^T) * J + aI]. I then have to multiply the inverse of Q with vector G to get vector M . M = (Q^(-1)) * G. I am using cblas and clapack to develop my algorithm. When matrix Q is populated using random numbers (type float) and inverted using the routines sgetrf_ and sgetri_ , the calculated inverse is correct . But when matrix Q is symmetrical , which

Cross-Compiling Armadillo Linear Algebra Library

不羁的心 提交于 2019-12-04 13:12:11
问题 I enjoy using the Armadillo Linear Algebra Library. It becomes extremely nice when porting octave .m files over to C++, especially when you have to use the eigen methods. However I ran into issues when I had to take my program from my native vanilla G++ and dump it onto my ARM processor. Since I spent a few hours muddling my way though it I wanted to share so others might avoid some frustration. If anyone else could add anything else I would love it. This was the process I used to tackle this

Dense Cholesky update in Python

大城市里の小女人 提交于 2019-12-04 11:28:17
问题 Could anyone point me to a library/code allowing me to perform low-rank updates on a Cholesky decomposition in python (numpy)? Matlab offers this functionality as a function called 'cholupdate'. LINPACK also has this functionality, but it has (to my knowledge) not yet been ported to LAPACK and hence isn't available in e.g. scipy. I found out that scikits.sparse offers a similar function based on CHOLMOD, but my matrices are dense. Is there any code available for python with 'cholupdate''s

Matrix-vector product with dgemm/dgemv

匆匆过客 提交于 2019-12-04 11:19:15
Using Lapack with C++ is giving me a small headache. I found the functions defined for fortran a bit eccentric, so I tried to make a few functions on C++ to make it easier for me to read what's going on. Anyway, I'm not getting th matrix-vector product working as I wish. Here is a small sample of the program. smallmatlib.cpp: #include <cstdio> #include <stdlib.h> extern "C"{ // product C= alphaA.B + betaC void dgemm_(char* TRANSA, char* TRANSB, const int* M, const int* N, const int* K, double* alpha, double* A, const int* LDA, double* B, const int* LDB, double* beta, double* C, const int* LDC)

Wrapping a LAPACKE function using Cython

心不动则不痛 提交于 2019-12-04 07:11:38
I'm trying to wrap the LAPACK function dgtsv (a solver for tridiagonal systems of equations) using Cython. I came across this previous answer , but since dgtsv is not one of the LAPACK functions that are wrapped in scipy.linalg I don't think I can use this particular approach. Instead I've been trying to follow this example . Here's the contents of my lapacke.pxd file: ctypedef int lapack_int cdef extern from "lapacke.h" nogil: int LAPACK_ROW_MAJOR int LAPACK_COL_MAJOR lapack_int LAPACKE_dgtsv(int matrix_order, lapack_int n, lapack_int nrhs, double * dl, double * d, double * du, double * b,

Correct way to point to ATLAS/BLAS/LAPACK libraries for numpy build?

送分小仙女□ 提交于 2019-12-04 06:28:02
I'm building numpy from source on CentOS 6.5 with no root access (python -V=2.7.6). I have the latest numpy source from git. I cannot for the life of me get numpy to acknowledge atlas libs. I have: ls -1 /usr/lib64/atlas libatlas.so.3 libatlas.so.3.0 libcblas.so.3 libcblas.so.3.0 libclapack.so.3 libclapack.so.3.0 libf77blas.so.3 libf77blas.so.3.0 liblapack.so.3 liblapack.so.3.0 libptcblas.so.3 libptcblas.so.3.0 libptf77blas.so.3 libptf77blas.so.3.0 I don't know anything about how these libs came about, but I can only assume that the atlas builds would be faster than any standard BLAS/LAPACK