Matlab vs. Scilab Rafael Brunner

What‘s going on? Few words about Scilab‘s origin Introduction to Scilab: - linear algebra - programming Parts of my term work: - sparse matrices - Savitzky-Golay filter - performance comparison My own experiences

Scilab developed since 1990 at INRIA / ENPC (France) open source free of charge high quality toolboxes available - artificial network - serial port similar to Matlab... yes, but...

Demo Linear Algebra - basics (how to enter matrices etc.) - compute with matrices - solving systems of equations - hessenberg form - LU-, QR-decomposition - eigenvalues, -vectors - SVD

Programming introduction / overview example: poisson2d_kron

Overview (1) for var = expr, statement; ...; statement; end while expression, statements; end if expr then statements; elseif expr then statements; else statements; end

Overview (2) select expr case expr1 then instructions1 ... case exprn then instructionsn [else instructions] end

Overview (3) [lhs,rhs] = argn(0) error warning

Example (demo) poisson2d_kron.m  poisson2d_kron.sci mfile2sci

2D-Poisson matrix

Sparse matrices Three different algorithms to generate the 2D-Poisson matrix: - set the elements one by one - block wise - kronecker product

Performance comparison

Solving a system Ax=b in this case Ax = 1 pcg (preconditioned conjugate gradients method) Scilab does not provide a pcg method  Scilin (IRISA)

Demo Solving Ax=1 for n=100 2D-Poisson matrix generated by poisson2d_kron

Performance comparison

Savitzky-Golay Filter measured data (slowly varying and corrupted by random noise) reconstruction of the underlying smooth function

Savitzky-Golay Filter (DEMO)

My own experiences editor translating - build up new functions - mfile2sci

Summary speed graphics signal processing

Is Scilab an alternative to Matlab?

In my opinion: Scilab is capable and can be an alternative to Matlab.