Mailman 3 May 2015 - SciPy-User

How to display a RGB image (MFISH)?
by jp April 3, 2023

April 3, 2023

Hi, I have written a script to try to combine five images into a three channels RGB images<http://dip4fish.blogspot.com/2011/05/trying-to-combine-mfish-images-into-rg…> . The resulting RGB image looks like a grey scale image instead of a color one. I have three np.array Rnorm, Gnorm, Bnorm which are copied into a rgb array: *rgb = np.zeros((shape[0],shape[1],3),dtype=float) mxr=np.max(R) mxg=np.max(G) mxb=np.max(B) Rnorm=np.uint8((255*(R/mxr)))Gnorm=np.uint8((255*(R/mxg)))Bnorm=np.uint8((255*(R/mxb)))#copy each RGB component in an RGB array rgb[:,:,0]=Rnorm rgb[:,:,1]=Gnorm rgb[:,:,2]=Bnorm* *pylab.subplot(224, aspect='equal',frameon=False, xticks=[], yticks=[]) pylab.imshow(rgb) pylab.show()* Any advice? Thank you Jean-Patrick

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Invitation to connect on LinkedIn
by Jelle Feringa via LinkedIn July 28, 2022

July 28, 2022

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Help required regding Eigenvectors
by Sudheer Phani March 14, 2022

March 14, 2022

Hello All, I have been encountering some strange problems with the calculation of eigen vectors using python. The problem is with the sign of the eigen vectors calculated. On Very few occasions the eigen vectors calculated using python have an opposite sign than the actual eigenvectors, though the magnitude is correct. Can any one of you plz help me in this regard and suggest me some solution if you have encoutered similar problems . Any help in this regd is appreciated Thanks in Advace regds Sudheer

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Playing numpy array over speakers
by Todd Oct. 17, 2015

Oct. 17, 2015

Is anyone aware of a well-maintained, simple, cross-platform python package that can play a numpy array as sound over speakers? I am aware of https://wiki.python.org/moin/Audio/. However, in all the cases there, as far as I can find they either do not support numpy arrays, are not cross-platform, cannot playback sound at all, or are unmaintained. There is also PySoundCard, which would do what I need but also appears to be unmaintained (no release in over a year, and no commits in 5 months, no release with serious bugfixes mentioned in commits).

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Constrained Optimization
by Arash M May 30, 2015

May 30, 2015

I am new to scipy, I am trying to s maximize x^(0.5)y^(0.5) st. x+y=10 using scipy. I can't figure out which method to use. I would really appreciate it if someone could guide me on this. and this is the code I have tried : from scipy.optimize import * import numpy as np def func(x, sign=1.0): """ Objective function """ return sign*(x[0]**(0.5)*2*x[1]**(0.5)) def func_deriv(x, sign=1.0): """ Derivative of objective function """ dfdx0 = sign*((0.5*x[0]**(-0.5))*x[1]**(0.5)) dfdx1 = sign*((0.5*x[1]**(-0.5))*x[0]**(0.5)) return np.array([ dfdx0, dfdx1 ]) cons = ({'type': 'eq', 'fun': lambda x: x[0] + x[1] - 10, 'jac' : lambda x: np.array([1.0, 1.0])}) res = minimize(func,(4,6),args=(-1.0,), jac=func_deriv,method='SLSQP', options={'disp': True}) print(res.x)

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Re: [SciPy-User] [Numpy-discussion] Verify your sourceforge windows installer downloads
by Andrew Collette May 29, 2015

May 29, 2015

> Here is their lame excuse: > > https://sourceforge.net/blog/gimp-win-project-wasnt-hijacked-just-abandoned/ > > It probably means this: > > If NumPy installers are moved away from Sourceforge, they will set up a > mirror and load the mirrored installers with all sorts of crapware. It is > some sort of racket the mob couldn't do better. I noticed that like most BSD-licensed software, NumPy's license includes this clause: "Neither the name of the NumPy Developers nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission." There's an argument to be made that SF isn't legally permitted to distribute poisoned installers under the name "NumPy" without permission. I recall a similar dust-up a while ago about "Standard Markdown" using the name "Markdown"; the original author (John Gruber) took action and got them to change the name. In any case I've always been surprised that NumPy is distributed through SourceForge, which has been sketchy for years now. Could it simply be hosted on PyPI? Andrew

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ANN: SfePy 2015.2
by Robert Cimrman May 29, 2015

May 29, 2015

I am pleased to announce release 2015.2 of SfePy. Description ----------- SfePy (simple finite elements in Python) is a software for solving systems of coupled partial differential equations by the finite element method or by the isogeometric analysis (preliminary support). It is distributed under the new BSD license. Home page: http://sfepy.org Mailing list: http://groups.google.com/group/sfepy-devel Git (source) repository, issue tracker, wiki: http://github.com/sfepy Highlights of this release -------------------------- - major code simplification (removed element groups) - time stepping solvers updated for interactive use - improved finding of reference element coordinates of physical points - reorganized examples - reorganized installation on POSIX systems (sfepy-run script) For full release notes see http://docs.sfepy.org/doc/release_notes.html#id1 (rather long and technical). Best regards, Robert Cimrman and Contributors (*) (*) Contributors to this release (alphabetical order): Lubos Kejzlar, Vladimir Lukes, Anton Gladky, Matyas Novak

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Re: [SciPy-User] [Numpy-discussion] Verify your sourceforge windows installer downloads
by David Cournapeau May 28, 2015

May 28, 2015

IMO, this really begs the question on whether we still want to use sourceforge at all. At this point I just don't trust the service at all anymore. Could we use some resources (e.g. rackspace ?) to host those files ? Do we know how much traffic they get so estimate the cost ? David On Thu, May 28, 2015 at 9:46 PM, Julian Taylor < jtaylor.debian(a)googlemail.com> wrote: > hi, > It has been reported that sourceforge has taken over the gimp > unofficial windows downloader page and temporarily bundled the > installer with unauthorized adware: > https://plus.google.com/+gimp/posts/cxhB1PScFpe > > As NumPy is also distributing windows installers via sourceforge I > recommend that when you download the files you verify the downloads > via the checksums in the README.txt before using them. The README.txt > is clearsigned with my gpg key so it should be safe from tampering. > Unfortunately as I don't use windows I cannot give any advice on how > to do the verifcation on these platforms. Maybe someone familar with > available tools can chime in. > > I have checked the numpy downloads and they still match what I > uploaded, but as sourceforge does redirect based on OS and geolocation > this may not mean much. > > Cheers, > Julian Taylor > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion(a)scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion >

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Computing derivatives with scipy.integrate.odeint
by Camille Chambon May 28, 2015

May 28, 2015

Hello, I'm trying to understand how scipy.integrate.odeint works. I wrote the following example: import numpy as np from scipy.integrate import odeint y0 = [2] def func(y, t): return [y[0]] t = np.arange(0, 4.0, 1.0) y = odeint(func, y0, t) print 'y', y It prints: y [[ 2. ] [ 5.43656382] [ 14.77811278] [ 40.17107594]] Why don't I get: y [[ 2. ] [ 4.] [ 8.] [ 16.]] ? My question is probably due to my limited knowledge in basic mathematics. Thanks for your help. Camille

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Structured array from dict
by Todd May 27, 2015

May 27, 2015

Is there a constructor to create a structured array from a dict in numpy?

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