Mailman 3 May 2009 - SciPy-User

Number of periods in a year in scikits.timeseries
by Abiel Reinhart 28 May '09

28 May '09

Is there an automated way to determine the number of periods in a year for a given frequency in scikits.timeseries? For instance, a monthly series has 12 periods in a year, and a daily series has 365.25. It would not be too hard just to create a table for this, but I wanted to first check if there was an automated way. This is useful when you want to be able to take annualized percent changes or differences. Thank you. Abiel

2 1

noncentral F distribution?
by Neal Becker 28 May '09

28 May '09

Does scipy have non central F distribution? (I need cdf for that)

3 9

integrating a system of differential equations
by ms 28 May '09

28 May '09

Hello, I have to integrate a huge system of differential equations. The system is such that for each time step, the solution of equation j-1 is a parameter for equation j, so they have to be all integrated together at the same time. I tried to do it myself but it seems whatever I do is by no means stable. Can one do that using odeint? I tried to look for odeint documentation but it's not very clear to me if it is possible (especially for someone like me not being exactly accustomed to numerical resolution of ODEs). Thanks! Massimo

4 7

Cov of 2 vectors
by sandeep.prasad＠tcs.com 28 May '09

28 May '09

Dear All, How do i compute the covar of 2 vectors. The cov module in scipy always returns a 2 by 2matrix even if the vectors are of len >2 , how is this possible?? However for the covariance of x and y i need a single number, are there any built in functions for this?? Regards, Sandeep Prasad Tata Consultancy Services Plot No 1, Survey No. 64/2, Software Units Layout Serilingampally Mandal, Madhapur Hyderabad,Andhra Pradesh India Ph:- 04066673582 Cell:- 9640795927 Mailto: sandeep.prasad(a)tcs.com Website: http://www.tcs.com ____________________________________________ Experience certainty. IT Services Business Solutions Outsourcing ____________________________________________ =====-----=====-----===== Notice: The information contained in this e-mail message and/or attachments to it may contain confidential or privileged information. If you are not the intended recipient, any dissemination, use, review, distribution, printing or copying of the information contained in this e-mail message and/or attachments to it are strictly prohibited. If you have received this communication in error, please notify us by reply e-mail or telephone and immediately and permanently delete the message and any attachments. Thank you

2 1

concave and convex function
by mudit sharma 27 May '09

27 May '09

I have following sample (actual dataset is much bigger): [ 0.48 0.64 0.69 0.67 0.67 0.65 0.68 0.63 0.62 0.61 0.61 0.6 0.58 0.62 0.64 0.63 0.63 0.61 0.60 0.61 0.62 0.65 0.67 0.67 0.67 0.68 0.68 0.66 0.68 0.65 0.65 0.65 0.65 0.64 0.64 0.65 0.65 0.66 0.66 0.64 0.65 0.64 0.68 0.69 0.70 0.69 0.7 0.68 0.64 0.64 0.65 0.67 0.68 0.67 0.67 0.66 0.66 0.64 0.64 0.58 0.53 0.53 0.52] I am looking to scan for all M & W curve formation and cycles. For this I need to detect all concave and convex points on curve. Is there function available in scipy or mlab to fit data into concave and convex function? If there's any other straightforward way to achieve this, pleas suggest. Thanks! M

4 8

[half OT?] best way to store a spectrum
by Davide Cittaro 27 May '09

27 May '09

Hi all, I have a bunch of spectra listed within a file (mass/intensity values). I'm planning to analyze them and match with theoretical spectra... In you opinion, which is the best way to store them for an efficient analysis? In the past this has been done with python arrays (i.e. a spectrum was an array of arrays, each peak was a mass/intensity array)... Thanks d /* Davide Cittaro Cogentech - Consortium for Genomic Technologies via adamello, 16 20139 Milano Italy tel.: +39(02)574303007 e-mail: davide.cittaro(a)ifom-ieo-campus.it */

3 5

fminbound now passes arrays, but used to pass numbers
by jason-sage＠creativetrax.com 27 May '09

27 May '09

In changeset 5205 (29 Nov 2008), to resolve #544, someone added the following code to the fminbound function in optimize/optimize.py: x1 = atleast_1d(x1) x2 = atleast_1d(x2) if len(x1) != 1 or len(x2) != 1: raise ValueError, "Optimisation bounds must be scalars" \ " or length 1 arrays" An effect of the first two lines is that the x value passed to the function a few lines later is no longer a single number, but an ndarray. This messes things up for us in the Sage project, where the calculations in the function may or may not know how to deal with an ndarray. Can we make x1 and x2 numbers if they were originally numbers? Otherwise, we have to wrap all of our functions in a (slow) python call lambda x: f(x[0]). Thanks, Jason -- Jason Grout

2 2

Print unicode objects in object arrays
by mmanns＠gmx.net 26 May '09

26 May '09

Hi Is there a way of printing unicode objects that are inside an object array? $ python Python 2.5.4 (r254:67916, Feb 17 2009, 20:16:45) [GCC 4.3.3] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> u = [u'\u201e'] >>> u [u'\u201e'] >>> import numpy >>> a = numpy.array(u, dtype="O") >>> a Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/lib/python2.5/site-packages/numpy/core/numeric.py", line 1088, in array_repr ', ', "array(") File "/usr/lib/python2.5/site-packages/numpy/core/arrayprint.py", line 287, in array2string separator, prefix) File "/usr/lib/python2.5/site-packages/numpy/core/arrayprint.py", line 216, in _array2string _summaryEdgeItems, summary_insert)[:-1] File "/usr/lib/python2.5/site-packages/numpy/core/arrayprint.py", line 333, in _formatArray word = format_function(a[-1]) UnicodeEncodeError: 'ascii' codec can't encode character u'\u201e' in position 0: ordinal not in range(128) >>> numpy.__version__ '1.2.1' Thanks in advance Martin

2 1

Import problem when using py2exe and scipy.
by Armando Serrano Lombillo 26 May '09

26 May '09

Hello list. I've run into a problem when packaging a program that uses scipy with py2exe. When the program tries to "from scipy import interpolate" I get an "ImportError: cannot import name factorial" coming from line 2 in scipy\interpolate\polyint.py. This problem doesn't pop when I run the program normally (that is, before packing it with py2exe). As a workaround, I can either go back to using scipy 0.6 or comment out line 2 in scipy\interpolate\polyint.py. I'm not the only one with this problem, as you can see here: http://article.gmane.org/gmane.comp.python.py2exe/3324 I'm using python 2.5.4 on Windows XP. Armando.

1 0

BOBYQA for scipy.optimize - has anyone willing to go for it?
by Dmitrey Kroshko 26 May '09

26 May '09

hi all, BOBYQA is state-of-the-art solver for NLP/NSP problems with box bounds lb <= x <= ub, when no user-supplied gradient/subgradient is available. License is BSD-like, language: fortran 77, author: Michael J.D. Powell. I have filed a ticket for scipy.optimize http://projects.scipy.org/scipy/ticket/950 Has anyone willing to go for it? Regards, D.

2 1