Mailman 3 February 2006 - SciPy-User

derivatives of datas?
by manouchk Feb. 8, 2006

Feb. 8, 2006

Hi, I'd like to calculate derivative curve of datas. Datas is of type first column =X and 2nd one Y=f(X) that can be put in 2 vector (for example). I'd like to know if scipy provides a function data derivatives (that I would have miss?), more advanced than a simple point to point linear derivative, using weighted spline for example... ? Emmanuel

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strange,frustrating error
by Ryan Krauss Feb. 8, 2006

Feb. 8, 2006

I am getting an error that is driving me crazy on code that used to work. And the really weird thing is that if I use the debugger to set a trace just before the error and step into the specific line that was causing the error, the code executes correctly. But if I just try to step over the line (debugger n vs. debugger s commands), I get the error. Here is the error message: /home/ryan/thesis/feedback_modeling/experiments/samii_model.py in __init__(self, beamparams, maxsize, symname, symlabel, symsub, usez) 44 class samiiBeam(TMM.beam.BeamElement): 45 def __init__(self,beamparams={'EI':339134.5276,'mu':5.7281,'L':4.6482},maxsize=ms,symname='Ubeam',symlabel='beam',symsub=True,usez=True): ---> 46 return TMM.beam.BeamElement.__init__(self,beamparams,maxsize=maxsize,symlabel=symlabel,symname=symname,symsub=symsub,usez=usez) 47 48 class samiiLink0(TMM.rigid.RigidMass): TypeError: unbound method __init__() must be called with BeamElement instance as first argument (got samiiBeam instance instead) WARNING: Failure executing file: <summary_report.py> Basically, I have a derived class trying to call its super-class (or parent class) constructor and getting the error that it isn't an instance of its own super-class. The super-class is defined in another module and imported (I used to import it with a from statement, but that wasn't working either today). I call this constructor at another place in the code: 67 beam=samiiBeam() and that is the line that generates an error if I just hit n in the debugger, but executes correctly if I step into it and exectute the __init__ method step-by-step. Any help, Ryan

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PyDSTool
by Alan G Isaac Feb. 8, 2006

Feb. 8, 2006

1. Is PyDSTool destined to be part of SciPy? This seems like a good idea ... 2. Was PyDSTool's scipy_ode.py forked from SciPy's ode.py for any reason other than lack of communication? Cheers, Alan Isaac PS The note in scipy_ode.py reads:: # This is a trivially-adapted version of the original SciPy integrate code. # Changes: (1) removed the annoying print statement whenever # the ODE code is 'found', which is unwanted screen output during # computations. # (2) Made ode a new-style class. # (3) Changed a lambda occurrence in one of the methods to use noneFn instead.

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Wrapping C libraries for Numeric integration
by Bryan Cole Feb. 8, 2006

Feb. 8, 2006

Hi All, What's the best approach for wrapping C libraries where the inputs/outputs are C arrays (which I want to pass to/from Numeric arrays)? I'm a regular SWIG user, but I don't have any typemaps to handle C-array-to-Numeric conversion and I can't see any distributed with SWIG. What approach is used by SciPy? (I know scipy is mostly fortran routines but surely you have a few C ones?). Can anyone point me to existing typemaps for this purpose, to save me writing my own. thanks, Bryan

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Re: [SciPy-user] Plotting libs removed but still out front on scipy.org
by Joe Harrington Feb. 8, 2006

Feb. 8, 2006

We agreed at the 2004 SciPy conference (or were we a workshop then?) and subsequent discussions to have finer-grained packaging (at least on *nix-based platforms), but to have umbrella packages that would use the dependency mechanism to pull in what a user needed. This would allow the faster-developing packages to release more frequently than the stable packages, but the user's system would still always have current stuff. We were also going to officially bless certain packages for plotting, etc., over others by means of documenting their use almost exclusively in the intro docs, including them in the umbrella packages, etc. We don't yet have official package releases for the new NumPy and SciPy, but we did agree that Matplotlib was going to be the plotting package of choice. So, I don't see why we can't put graphics made with it on the front page, or anywhere else. Plus, the site isn't just for SciPy, it's a portal for all scientific computing in Python, so *any* python-generated graphics should be fine (though I'd lobby strongly for open-source only, and "blessed" packages except where otherwise specifically called for). I also think that, in most cases, clicking on a graphic on the site should take you to the recipe for creating it. Aside from giving full disclosure, it is also very educational. --jh--

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Plotting libs removed but still out front on scipy.org
by Kael Fischer Feb. 7, 2006

Feb. 7, 2006

I think it's potentially confusing to have the pretty picture on the scipy.org main page show functionality that scipy no longer has. More importantly, thanks to whoever added the cov_x to leastsq ! Kael -- Kael Fischer, Ph.D DeRisi Lab - Univ. Of California San Francisco 415-514-4320

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Re: [SciPy-user] Wrapping C libraries for Numeric integration
by Joe Harrington Feb. 7, 2006

Feb. 7, 2006

Pearu, That's a great and very simple example! Would you be willing to turn it into a Cookbook page? Thanks! --jh--

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Submitting images to the wiki
by Hugo Gamboa Feb. 6, 2006

Feb. 6, 2006

What is the process of introducing images in the scipy wiki? I would like to introduce a companion image for an example in the cookbook. Hugo Gamboa

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new on the list
by Nico Feb. 6, 2006

Feb. 6, 2006

Hi. I'm a new user of the numpy-discussion and scipy-user mailing-lists. So, as I usually do, here are a few words about me and my use of numpy/scipy. I am a doctorate student, in Paris; I will work on numerical analysis, mesh generation and image processing, and I intend to do the prototyping (and maybe everything) of my works with python. I recently choosed python because... - flexible and rich language for array manipulation - seems a good language to help me write clean, clear, bug-free and reusable code - seems possible to make a GUI frontend without too much pain - seems OK to glue with various other C/fortran applications without to much pain - free, as in free beer (I had to work on Matlab previously, and I don't like to force people pay for an expensive licence if they are interested in my work) - free, as in free speech (... I also had serious problems, needing compatibility of Matlab with a linux kernel not officially supported) I use numpy/scipy on Debian/Ubuntu, building from the release tarballs. And I am currently reading the available documentation... Last thing: What about a #scipy irc channel? I feel there are too many people on irc.freenode.org/#python for an efficient use. Happy coding! -- Nico

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symbolic strings
by Ryan Krauss Feb. 5, 2006

Feb. 5, 2006

I may be getting in over my head, but I think this can work. I do a lot of analysis with matrices using the transfer matrix method. Sometimes I want to do numeric work with them and sometimes I use python to generate an input script for Maxima. Right now I have two methods for my transfer matrix element, one that outputs a numeric matrix and one that outputs a string for Maxima. I am working on a new element and would like to combined these two expressions by creating a symbolic string method so that expressions like a=-(L0*m1*r1*s**2-c1*s-k1)/(c1*s+k1) make sense whether L0, m1, r1, s, etc are floats or symstrs (my new class). I overrode the __mul__, __add__, __div__,__sub__, and __pow__ methods but don't know if there are methods to override to deal with the parenthesis and the unary - out in front. Can this be done with only a little bit more work? Basically I want the output of this expression to be 'a=-(L0*m1*r1*s**2-c1*s-k1)/(c1*s+k1)' if it is a string and a float or complex if the variables are numbers. Thanks, Ryan

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