blas

I installed atlas, blas and lapack x86_64 packages via yum install atlas.x86_64 blas.x86_64 lapack.x86_64 on a Redhat 6.6 (ii) distro which installs a shared library but am having problems compiling and linking. For example, if I try to compile the minimal working example: program main print *, 'hello world' end program main using gfortran -L. main.f90 -llapack -lblas -o main the compiler doesn't find the libraries and I get the error message: /usr/bin/ld: cannot find -llapack collect2: ld returned 1 exit status I'm relatively new to fortran and linux so I'm probably missing something obvious.

I'm new to numerical linear algebra, and I have just started using LAPACK and BLAS. Is there a routine that can copy/convert a symmetric matrix between packed and full storage? I have found dtrttp , which I can use to convert a double-precision full symmetric matrix to packed storage. However, these routines are meant for triangular matrices, so the corresponding dtpttr only fills a triangle of the full matrix. How can I fill the other half? The obvious solution is to symmetrize the matrix by a "home-made/diy" code, the risk being to re-invent the wheel. It is pretty easy to write the for

I have a working LAPACK implementation and that, as far as I read, contains BLAS. I want to use SPARSE BLAS and as far as I understand this website , SPARSE BLAS is part of BLAS. But when I tried to run the code below from the sparse blas manual using g++ -o sparse.x sparse_blas_example.c -L/usr/local/lib -lblas && ./sparse_ex.x the compiler (or linker?) asked for blas_sparse.h. When I put that file in the working directory I got: ludi@ludi-M17xR4:~/Desktop/tests$ g++ -o sparse.x sparse_blas_example.c -L/usr/local/lib -lblas && ./sparse_ex.x In file included from sparse_blas_example.c:3:0:

Im starting to use BLAS functions in c++ (specifically intel MKL) to create faster versions of some of my old Matlab code. Its been working out well so far, but I cant figure out how to perform elementwise multiplication on 2 matrices (A .* B in Matlab). I know gemv does something similar between a matrix and a vector, so should I just break one of my matrices into vectprs and call gemv repeatedly? I think this would work, but I feel like there should be aomething built in for this operation. Use the Hadamard product. In MKL it's v?MUL . E.g. for doubles: vdMul( n, a, b, y ); in Matlab

I have a question regarding cblas_dgemv. I am trying to understand how it works. And what I am possibly doing wrong. I have an array Matrix and then I try to read that matrix RowMajor and ColumnMajor. I am getting the expected result in the RowMajor Case; [6, 2, 4, 6]'. However for the ColMajor, I am getting [-7, 3, 0, 5]' when the answer should be [6, 3, 2, 3]' Here is my code. I am using Intel MKL. #include <stdio.h> #include <stdlib.h> #include <math.h> #include <mkl.h> #define NCols 5 #define Nrows 4 double A[] = { 8, 4, 7, 3, 5, 1, 1, 3, 2, 1, 2, 3, 2, 0, 1, 1 , 2, 3, 4, 1}; double x[] =

When I try to import numpy, I get the following error: /usr/local/lib/python2.7/dist-packages/numpy/linalg/__init__.py in <module>() 49 from .info import __doc__ 50 ---> 51 from .linalg import * 52 53 from numpy.testing import Tester /usr/local/lib/python2.7/dist-packages/numpy/linalg/linalg.py in <module>() 27 ) 28 from numpy.lib import triu, asfarray ---> 29 from numpy.linalg import lapack_lite, _umath_linalg 30 from numpy.matrixlib.defmatrix import matrix_power 31 from numpy.compat import asbytes ImportError: /usr/lib/liblapack.so.3: undefined symbol: gotoblas I have already tried solutions