[Maxima] Maxima Lapack is very slow: 7 seconds versus 0.002 seconds in Julia.

[Manuel Pedrinero rossetil]

Recently Raimond Toy asked about what capabilities are lacking in maxima, numeric computations in linear algebra seems to be very slow 
 
 This is an example in gcl using lapack

(%i1) load(lapack);
/share/lapack/binary-gcl/dgemm.o
(%o1)          /usr/share/maxima/5.24.0/share/lapack/lapack.mac
(%i2) h[i,j]:= 1/(i+j);
                                           1
(%o2)                           h     := -----
                                 i, j    i + j
(%i3) m : genmatrix(h,50,50)$

(%i4) showtime : true;
Evaluation took 0.0000 seconds (0.0000 elapsed)
(%o4)                                true
(%i5) [one,two,three] : dgeev(m)$
Evaluation took 7.3200 seconds (7.4000 elapsed)

In Julia computing eigenvalues of a 50x50 matrix whose entries are random numbers from a normal distribution is about 0.007 seconds.

julia> @time v1,others = eig(randn(50,50));
elapsed time: 0.0070650577545166016 seconds



 The same computation takes 0.002 seconds in Julia. (first make some computation
with eig so that it loads the function in memory).

filewrite("path/file",m);

to convert m to Julia format one can use system and sed
replacing "," => "space"   "]" by ";" and deleting "["  
the final step is to put parenthesis around the numbers (that are separated by space inside rows and ";" separate rows.

Julia:

@time one,others = eig(m)
 

Maxima version: 5.24.0
Maxima build date: 9:11 2/29/2012
Host type: x86_64-unknown-linux-gnu
Lisp implementation type: GNU Common Lisp (GCL)
Lisp implementation version: GCL 2.6.7

  I know that some efforts like matlisp are trying to improve this situation. 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.math.utexas.edu/pipermail/maxima/attachments/20120505/673ce1fa/attachment.html>