Mailman 3 April 2020 - SciPy-User

How to display a RGB image (MFISH)?
by jp 03 Apr '23

03 Apr '23

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 28 Jul '22

28 Jul '22

LinkedIn ------------ Jelle Feringa requested to add you as a connection on LinkedIn: ------------------------------------------ Jose, I'd like to add you to my professional network on LinkedIn. - Jelle Accept invitation from Jelle Feringa http://www.linkedin.com/e/-3wy1w2-gpkzwpgn-5n/Q6WKH0LACopGJkAw_6fSqajo6R7VM… View invitation from Jelle Feringa http://www.linkedin.com/e/-3wy1w2-gpkzwpgn-5n/Q6WKH0LACopGJkAw_6fSqajo6R7VM… ------------------------------------------ DID YOU KNOW your LinkedIn profile helps you control your public image when people search for you? Setting your profile as public means your LinkedIn profile will come up when people enter your name in leading search engines. Take control of your image! http://www.linkedin.com/e/-3wy1w2-gpkzwpgn-5n/ewp/inv-22/ -- (c) 2011, LinkedIn Corporation

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Help required regding Eigenvectors
by Sudheer Phani 14 Mar '22

14 Mar '22

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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Interpolator coefficients for Radau method in solve_ivp
by Travis Czechorski 29 Apr '20

29 Apr '20

Hello, I am trying to figure out how to calculate the following coefficients in the source code for the Radau integration method. # Interpolator coefficients.P = np.array([ [13/3 + 7*S6/3, -23/3 - 22*S6/3, 10/3 + 5 * S6], [13/3 - 7*S6/3, -23/3 + 22*S6/3, 10/3 - 5 * S6], [1/3, -8/3, 10/3]])

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ANN: pvlib v0.7.2
by Dr. Mark Alexander Mikofski PhD 23 Apr '20

23 Apr '20

pvlib has a new minor release, v0.7.2 Release Notes: https://pvlib-python.readthedocs.io/en/v0.7.2/whatsnew.html PyPI: https://pypi.org/project/pvlib/ Read the Docs: https://pvlib-python.readthedocs.io/en/latest/ GitHub: https://github.com/pvlib/pvlib-python Highlights: - add new module pvlib.snow to contain models related to snow coverage and effects on a PV system. (GH764< https://github.com/pvlib/pvlib-python/pull/764>) - Renamed pvlib.losses to pvlib.soiling. Additional loss models will go into code modules named for the loss or effect type. (GH935< https://github.com/pvlib/pvlib-python/issues/935>, GH891< https://github.com/pvlib/pvlib-python/issues/891>) - updated compatibility with cftime 1.1. (GH895< https://github.com/pvlib/pvlib-python/issues/895>) There are a few breaking API changes and bug fixes. Users are advised to read the release notes before updating. ---------- Forwarded message --------- From: Stark, Cameron Thomas via Python-announce-list < python-announce-list(a)python.org> Date: Wed, Apr 22, 2020, 5:58 PM Subject: pvlib v0.7.2 To: Cc: Stark, Cameron Thomas <ctstark(a)sandia.gov> pvlib has a new minor release, v0.7.2 Release Notes: https://pvlib-python.readthedocs.io/en/v0.7.2/whatsnew.html PyPI: https://pypi.org/project/pvlib/ Read the Docs: https://pvlib-python.readthedocs.io/en/latest/ GitHub: https://github.com/pvlib/pvlib-python Highlights: - add new module pvlib.snow to contain models related to snow coverage and effects on a PV system. (GH764< https://github.com/pvlib/pvlib-python/pull/764>) - Renamed pvlib.losses to pvlib.soiling. Additional loss models will go into code modules named for the loss or effect type. (GH935< https://github.com/pvlib/pvlib-python/issues/935>, GH891< https://github.com/pvlib/pvlib-python/issues/891>) - updated compatibility with cftime 1.1. (GH895< https://github.com/pvlib/pvlib-python/issues/895>) There are a few breaking API changes and bug fixes. Users are advised to read the release notes before updating. -- Python-announce-list mailing list -- python-announce-list(a)python.org To unsubscribe send an email to python-announce-list-leave(a)python.org https://mail.python.org/mailman3/lists/python-announce-list.python.org/ Support the Python Software Foundation: http://www.python.org/psf/donations/

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Doubt about float16 type support on scipy.signal.convolve2d method
by quic_sanirudh 21 Apr '20

21 Apr '20

Hi, I'm new to this community and in general to scipy. I tried to use the scipy.signal.convolve2d method with the call shown below, where a and b are of types float16. scipy.signal.convolve2d(a, b, mode='valid') I get the below error, and wanted to check if float16 types are not supported in the convolve2d method by design or if this could be a missed feature. ValueError: convolve2d not available for this type. Let me know if I have made any mistakes or if this I can perform float16 convolve2d using a different function perhaps. Thanks, Anirudh

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NumPy 1.18.3 released.
by Charles R Harris 19 Apr '20

19 Apr '20

Hi All, On behalf of the NumPy team I am pleased to announce that NumPy 1.18.3 has been released. This release contains various bug/regression fixes for the 1.18 series The Python versions supported in this release are 3.5-3.8. Downstream developers should use Cython >= 0.29.15 for Python 3.8 support and OpenBLAS >= 3.7 to avoid errors on the Skylake architecture. Wheels for this release can be downloaded from PyPI <https://pypi.org/project/numpy/1.18.3>, source archives and release notes are available from Github <https://github.com/numpy/numpy/releases/tag/v1.18.3>. *Highlights* Fix for the method='eigh' and method='cholesky' options in numpy.random.multivariate_normal. Those were producing samples from the wrong distribution. *Contributors* A total of 6 people contributed to this release. People with a "+" by their names contributed a patch for the first time. - Charles Harris - Max Balandat + - @Mibu287 + - Pan Jan + - Sebastian Berg - @panpiort8 + *Pull requests merged* A total of 5 pull requests were merged for this release. - #15916: BUG: Fix eigh and cholesky methods of numpy.random.multivariate_normal - #15929: BUG,MAINT: Remove incorrect special case in string to number... - #15930: BUG: Guarantee array is in valid state after memory error occurs... - #15954: BUG: Check that pvals is 1D in _generator.multinomial. - #16017: BUG: Alpha parameter must be 1D in _generator.dirichlet Cheers, Charles Harris

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optimize.least_squares memory allocation every function call
by Brian Hare 14 Apr '20

14 Apr '20

I have a question about the scipy.optimize.least_squares function. I have found that the function to optimize needs to reallocate the return array every time the function is called. I've tried having the calling function return the same array every time (just re-filled with the correct return values), but least_squares doesn't seem to converge when I do this. I do not like having to allocate memory in the calling function, this seems slow and unnecessary. Is there a way around this? If not, could scipy.optimize.least_squares be adjusted so this is possible? The Gnu Scientific Library (which I sometimes fall back on when scipy.optimize.least_squares is too slow, I think this allocation issue is one major contributor), passes an array to the calling function to fill. Thank you, Brian Hare

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Thermal radiation heat transfer between surfaces
by Paweł Kwaśniewski 10 Apr '20

10 Apr '20

Dear SciPy community, I'm a bit stuck trying to simulate heat transfer by radiation only (elements in a vacuum chamber). The problem involves calculating the so called view factor (well explained in section 4 of http://mafija.fmf.uni-lj.si/seminar/files/2015_2016/Thermal_radiation_heat_…), which is a double surface integral. I was hoping to find some ready Python code, but I failed. Maybe someone is aware of either heat transfer calculation libraries in Python or just 3D view factor calculations? If not, maybe some hints on numerical calculations of surface integrals in Python? I've found view3d <https://sourceforge.net/p/view3d/code/HEAD/tree/trunk/README.txt#l48>, but the code is rather outdated and I'm struggling to compile it (I tried Windows 10, Archinux, Ubuntu, but I'm an amateur in software building). Best, Pawel

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