Gnuplot is a portable command-line driven graphing utility for Linux, OS/2, MS Windows, OSX, VMS, and many other platforms. The source code is copyrighted but freely distributed (i.e., you don’t have to pay for it). It was originally created to allow scientists and students to… Read more
I recently flew from Spokane to Seattle, Washington on an Alaska/Horizon Air Bombardier Q400 aircraft, similar to the one in the above image. This model aircraft has two Pratt & Whitney Canada PW150A turboprop engines. I captured the following video during cruise using a Motorola/Android… Read more
Here is a Fortran program which performs matrix inversion using the LU decomposition method: INVERSE_MATRIX.F It is compiled via: gfortran -o INVERSE_MATRIX INVERSE_MATRIX.F -llapack It compiles & runs under both Ubuntu & Cygwin. See also: http://www.nag.com/numeric/fl/nagdoc_fl23/examples/source/f07ajfe.f90 * * * The INVERSE_MATRIX.F program uses the subroutines:… Read more
This is another matrix multiplication project using the BLAS function dgemm. It is complied and run in an Ubuntu system. The set consists of two programs: (right mouse click. save target or link as) matrix_mult_cf.cpp fort_matmul_main.f The set calculates: C = A*B The C++ program… Read more
I am evaluating plotting programs for Ubuntu. I already have plotting capability via Matlab and Python/matplotlib running under Ubuntu. The Matlab export plot quality is ok but not great. So far my Python knowledge only extends to making static plots. Identifying interactive, dynamic plotting methods… Read more
The make install command is necessary to build certain software package. This may result in an error such as: /usr/local/lib: Permission denied The problem can be fixed by typing: su -c “make install” Then enter root password when prompted * * * The Update Manager… Read more
CBLAS is C interface to the BLAS library. * * * Ubuntu Installation instructions: BLAS must be installed first. The instructions for BLAS are given at: Generalized Eigenvalue Problem & BLAS Next, wget http://www.netlib.org/blas/blast-forum/cblas.tgz tar zxf cblas.tgz Go to CBLAS folder. Open Makefiles.in in a… Read more
Here is a program that uses dgemm to multiply two matrices: matrix_mult.cpp The dgemm function is implemented using gsl blas. It can be compiled under Cygwin as: gcc -o matrix_mult_alt matrix_mult_alt.cpp -lgsl -lstdc++ And under Ubuntu as: gcc -o matrix_mult_alt matrix_mult_alt.cpp -lgsl -lgslcblas -lstdc++ *… Read more
Blas and Lapack may be installed on an Ubuntu system using the instructions at: Generalized Eigenvalue Problem * * * C++ programs that use Lapack can be compiled in Terminal or Bash shell mode via: g++ file_in -o file_out -lgfortran -llapack -lm where file_in is… Read more
The goal of this project is to solve a “very large” generalized eigenvalue problem in a “reasonable” amount of time using library functions. The mass and stiffness matrices may be either dense or sparse. Optimum routines are desired for each case. Here is description of… Read more