Mailman 3 December 2000 - NumPy-Discussion

CVS updated but cannot release 17.2.0
by Paul F. Dubois Dec. 11, 2000

Dec. 11, 2000

I have CVS updated with fixes to MA, and the optimization for ones, etc. I can't release the files because they lost the upload server that does that and until they get the replacement online there are no new file releases. Developers, there are bug reports for FFT and savespace that need attention from the corresponding experts. The patch list is clear. We have completed the refereed papers program for IPC9 and it will be released shortly after notification of authors. The program is quite good, plus there are tutorials and two other tracks. I encourage all Nummies to attend (March, Long Beach CA; see python9.org). Registration has just opened.

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Bug in MA
by Paul F. Dubois Dec. 6, 2000

Dec. 6, 2000

It has come to my attention that the Masked Array package, MA, has a rather severe bug. The bug occurs when doing a mixed scalar/array operation in which the array has its first element masked. The bug causes the value computed by this operation to be wrong. I should have a fix for this problem shortly but since this bug is so severe I thought I should put out a warning immediately. This bug was introduced a few versions ago.

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Re: [Numpy-discussion] RE: Numpy
by rlw＠stsci.edu Dec. 6, 2000

Dec. 6, 2000

>From taylor(a)rhino.llnl.gov Wed Dec 6 13:23 EST 2000 > >I think a more portable solution is to just make it all an if statement. >I'm not comfortable with presuming that floats are always 4 bytes. I agree -- I also had the thought of changing to an if statement after I sent my mail. Much better than the switch since it can't break. >I've thrown in the int and float cases to make sure we cover every >machine that may be out there. I suspect that if float is 8 bytes then int will be too. Just char, short, float, and double should suffice. If the 4-byte version is missing it will just fall back on the default (slower but otherwise OK), and if the C compiler doesn't support shorter data items then probably the user won't be using them anyway... Rick White

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Re: [Numpy-discussion] RE: Numpy
by rlw＠stsci.edu Dec. 6, 2000

Dec. 6, 2000

A suggestion for an easy way to fix this problem: use float instead of long. Presumably floats are always 4 bytes. Rick Paul Dubois writes: >This was a patch that I put in before making this release. If you get 17.1.1 >it won't be in there. > > [...] > >cc: Error: Src/arrayobject.c, line 79: The switch statement containing this >case label already has a case label for "8". (dupcase) > case sizeof(double): >------------^ >error: command 'cc' failed with exit status 1 >tc05:/usr/tmp/chase/Numeric-17.1.2[408] > > >int do_sliced_copy(char *dest, int *dest_strides, int *dest_dimensions, > int dest_nd, char *src, int *src_strides, > int *src_dimensions, int src_nd, int elsize, > int copies) { > int i, j; > > if (src_nd == 0 && dest_nd == 0) { > switch(elsize) { > case sizeof(char): > memset(dest, *src, copies); > break; > case sizeof(short): > for(j=copies; j; --j, dest += sizeof(short)) > *(short*)dest = *(short*)src; > break; > case sizeof(long): > for(j=copies; j; --j, dest += sizeof(int)) > *(int*)dest = *(int*)src; > break; > case sizeof(double): > for(j=copies; j; --j, dest += sizeof(double)) > *(double*)dest = *(double*)src; > break; > default: > for(j=copies; j; --j, dest += elsize) > memcpy(dest, src, elsize); > } > return 0; > }

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RE: Numpy
by Paul F. Dubois Dec. 5, 2000

Dec. 5, 2000

This was a patch that I put in before making this release. If you get 17.1.1 it won't be in there. Developers -- I'm busy right now with the Python conference; can someone fix this for me and make a new distribution? -----Original Message----- From: Lila Chase [mailto:chase@tc05.llnl.gov] Sent: Tuesday, December 05, 2000 3:45 PM To: dubois1(a)llnl.gov Subject: Numpy Paul, First attempt at installing Numeric Python on Teracluster; fails. Lila tc05:/usr/tmp/chase/Numeric-17.1.2[407] !393 python setup_all.py install running install running build running build_py not copying Lib/ArrayPrinter.py (output up-to-date) not copying Lib/Numeric.py (output up-to-date) not copying Lib/Precision.py (output up-to-date) not copying Lib/UserArray.py (output up-to-date) not copying Lib/numeric_version.py (output up-to-date) running build_ext building '_numpy' extension skipping Src/_numpymodule.c (build/temp.osf1-V4.0-alpha-2.0/Src/_numpymodule.o up-to-date) cc -O -Olimit 1500 -IInclude -I/g/g16/chase/include/python2.0 -c Src/arrayobject.c -o build/temp.osf1-V4.0-alpha-2.0/Src/arrayobject.o cc: Error: Src/arrayobject.c, line 79: The switch statement containing this case label already has a case label for "8". (dupcase) case sizeof(double): ------------^ error: command 'cc' failed with exit status 1 tc05:/usr/tmp/chase/Numeric-17.1.2[408] int do_sliced_copy(char *dest, int *dest_strides, int *dest_dimensions, int dest_nd, char *src, int *src_strides, int *src_dimensions, int src_nd, int elsize, int copies) { int i, j; if (src_nd == 0 && dest_nd == 0) { switch(elsize) { case sizeof(char): memset(dest, *src, copies); break; case sizeof(short): for(j=copies; j; --j, dest += sizeof(short)) *(short*)dest = *(short*)src; break; case sizeof(long): for(j=copies; j; --j, dest += sizeof(int)) *(int*)dest = *(int*)src; break; case sizeof(double): for(j=copies; j; --j, dest += sizeof(double)) *(double*)dest = *(double*)src; break; default: for(j=copies; j; --j, dest += elsize) memcpy(dest, src, elsize); } return 0; }

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numpy on alpha/64bit
by Matthias Klose Dec. 3, 2000

Dec. 3, 2000

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Re: [Python-Help] Numeric bug, or my misunderstanding?
by Daniel Yoo Dec. 3, 2000

Dec. 3, 2000

On Fri, 1 Dec 2000, chad scherrer wrote: > >>> import Numeric > >>> def mod2(x): return x%2 > >>> apply(mod2, [-3]) > 1 > >>> apply(mod2, Numeric.array([-3])) > 1 > >>> apply(mod2, Numeric.array([[-3]])) > array([-1]) > > Should that not be array([1]) ? Hmmm. Good point; This looks weird to me too. You should probably talk to the Numeric Python people at the Numpy-discussion newsgroup: http://lists.sourceforge.net/mailman/listinfo/numpy-discussion I'll try to forward this message to that group, so perhaps they'll be able to figure out if it's a true bug. I hope that your answer will be answered quickly. Good luck!

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matrixmultiply implementation
by Christopher Lee Dec. 1, 2000

Dec. 1, 2000

I'm curious to see if anyone has looked at the implementation of dot/matrixmultiply recently. I was doing a benchmark lapack-based matrix inversion and was surprised to find that the accuracy check was taking longer than the inversion. The bottleneck was the matrix multiply. It appears that a blas dgemm implementation might give a large improvement. Here is a sample benchmark using PyLapack's dblas.dgemm for comparison. Results for a 1000 x 1000 matrix inversion: time elapsed for inverse (sec) 10.050768 time elapsed for matrixmultiply (sec) 24.142714 time elapsed for dgemm-matrixmultiply (sec) 5.997188 max error is: 3.30398486348e-10 Given the "dot" code doesn't look too bad, so I might be able to add dgemm support myself, at least for some cases. -chris p.s. I'll include the test code below ##################################### import time from Numeric import * from LinearAlgebra import * import dblas for N in [5,100, 1000]: a = reshape(arange(float(N*N)), (N,N)) + identity(N) # print "typecode of array is: ", a.typecode() start = time.time() inv_a = inverse(a) stop = time.time() # print inv_a startmult = time.time() b = matrixmultiply(a, inv_a) stopmult = time.time() residual = b - identity(N) #DGEMM(TRANSA, TRANSB, M, N, K, ALPHA,A, LDA, B, LDB, BETA,C,LDC) C = zeros(a.shape, a.typecode()) alpha = array([1.0]) beta = array([1.0]) startdgemm = time.time() dblas.dgemm('N','N', N,N,N, alpha, a,N, # A, LDA inv_a, N, # B, LDB beta, # BETA C, N) stopdgemm = time.time() # print C print "%d x %d matrix inversion" % (N,N) print "max error is:", print maximum.reduce(fabs(ravel(residual))) print "time elapsed for inverse (sec) %f" % (stop-start) print "time elapsed for matrixmultiply (sec) %f" % (stopmult-startmult) print "time elapsed for dgemm-matrixmultiply (sec) %f" % (stopdgemm-startdgemm) print

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Re: Installed python-numeric 17.1.2-1 (all source i386)
by Christopher C. Chimelis Dec. 1, 2000

Dec. 1, 2000

Doh, found a problem and am still trying to figure out what the best way to fix it is. In Src/arrayobject.c, starting at around line 70: int do_sliced_copy(char *dest, int *dest_strides, int *dest_dimensions, int dest_nd, char *src, int *src_strides, int *src_dimensions, int src_nd, int elsize, int copies) { int i, j; if (src_nd == 0 && dest_nd == 0) { switch(elsize) { case sizeof(char): memset(dest, *src, copies); break; case sizeof(short): for(j=copies; j; --j, dest += sizeof(short)) *(short*)dest = *(short*)src; break; case sizeof(long): for(j=copies; j; --j, dest += sizeof(int)) *(int*)dest = *(int*)src; break; case sizeof(double): for(j=copies; j; --j, dest += sizeof(double)) *(double*)dest = *(double*)src; break; default: for(j=copies; j; --j, dest += elsize) memcpy(dest, src, elsize); } return 0; } The problem is, that sizeof(long) = sizeof(double) on Alpha (and probably on the other 64-bit archs). So, what do you think the best method of handling this is? I don't know the package well anymore or else I'd fix it :-P C

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RE: [numpy - Help] Numeric-17.1.2.tar.gz missing
by Paul F. Dubois Dec. 1, 2000

Dec. 1, 2000

I succeeded in getting the file at 2 p.m. Friday Dec 1 Pacific Standard Time. I had received a similar report earlier in the day so I don't think you're crazy, just that something at SF was down. -----Original Message----- From: noreply(a)sourceforge.net [mailto:noreply@sourceforge.net] Sent: Thursday, November 30, 2000 9:23 AM To: noreply(a)sourceforge.net Subject: [numpy - Help] Numeric-17.1.2.tar.gz missing Read and respond to this message at: http://sourceforge.net/forum/message.php?msg_id=80631 By: vanandel There are no Numeric 17 tar files on http://download.sourceforge.net/numpy/ Could someone replace them? Thanks! ______________________________________________________________________ You are receiving this email because you elected to monitor this forum. To stop monitoring this forum, login to SourceForge and visit: http://sourceforge.net/forum/monitor.php?forum_id=3848

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