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Questions tagged [simplex]

A simplex is a generalization of the notion of a triangle or tetrahedron to arbitrary dimension.

129 questions
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NumPy vs SymPy Row operations different?

I cannot understand for the life of me why a row operation with NumPy just clearly leads to the wrong answer. The correct answer is in the SymPy matrix. Can anyone tell me why NumPy is unable to perform the correct calculation? I'm going crazy.…
James Salafatinos
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Error trying to run SWI Prolog Simplex example

I'm trying to run the coins example given in SWI-Prolog's simplex library documentation, but I'm getting this error message: $ rlwrap swipl coins.pl Warning: /home/vitorferraz/junk/coins.pl:1: Unknown message: simlpex(bounded) Welcome to SWI-Prolog…
Vitor F.M.
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Why is each iteration in Nelder-Mead in scipy so slow?

I'm trying to minimize a function using Nelder-Mead as implemented in scipy.minimize(method='Nelder-Mead'). The function has about 30 inputs, but I have been optimizing sequentially (i.e. optimize over the first 5, keep remaining 25 fixed, then…
Superpronker
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Revised Simplex Method - Matlab Script

I've been asked to write down a Matlab program in order to solve LPs using the Revised Simplex Method. The code I wrote runs without problems with input data although I've realised it doesn't solve the problem properly, as it does not update the…
gabrieleguidoni
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Solving linear system of equations with Prolog library Simplex

I am trying to use SWI-Prolog simplex library to solve a linear system of equations with the set of real numbers as domain. Would anyone please have a clue why the following query does not succeed? maximize( [], state( 0, [], [ c(0, [-…
catbow
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LP: postive reduced costs corresponding to positive variables?

I have the next LP problem Maximize 1000 x1 + 500 x2 - 500 x5 - 250 x6 Subject To c1: x1 + x2 - x3 - x4 = 0 c2: - x3 + x5 = 0 c3: - x4 + x6 = 0 With these Bounds 0 <= x1 <= 10 0 <= x2 <= 15 0 <= x5 <= 15 0 <= x6 <= 5 By solving…
Andrea Bustillos
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How to select from the output of scipy Delaunay triangulation only simplices under certain volume (or under total line length)?

I am using the Delaunay triangulation on a set of points, trying to isolate clusters of points in a regular pattern. My first experience with using the qhull.Delaunay object so bear with me... from scipy.spatial import Delaunay tri =…
Cate
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"Stitching" multiple 2d Arrays

EDIT (rephrased question): How would I use the provided smoothstep function to create a gradual transition between adjacent 2d arrays? Each array is the same size and contain values ranging between 0 and 1, having a smooth transition from edge to…
Johnathan Ralls
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Nelder-Mead initial simplex size

I use Matlab's fminsearch function for finding the minimum with Nelder-Mead. fminsearch calculates the size of the initial simplex automatically. In my case, the initial simplex is too small, thus it performs not well. fminsearch uses a leg of…
machinery
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R - nolptr - Find the 50 better solutions, not only the best one

I'm using the nerldermead() function of the nolptr package and I would like to find, for instance, the 50 most likely solutions. In this example : opti= function(x){x-12} x0=c(0) lower=c(0) …
R_SOF
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Get vertexes of object by simplex method

I'd like to find a vertexes of objects, which is determined by some equations. For example. Eq1: 2x + y + z <= 12; Eq2: x + y >= 23; Eq3: x + y + z <= 10; And it's limited by x >= 0 y >= 0 z => 0 And it gives a hexahedron. I want to…
Pavvi
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What is complexity of simplex algorithm for binary integer programming?

What is complexity of simplex algorithm for binary integer programming problem? For worst case or average case? I'm solving assignment…
mmswe
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Optimization task in R (Integer values, SImplex)

I have an optimization task. I use simples method, however my only question is how do I make X2, X4, X5 - integer and X1, X3, X6, X7 - any real numbers? My current code is as follows: library(boot) a =c(6,10,2,1,6,7,1) A11=…
user3810441
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Speed up simplex algorithm

I am playing around with a great simplex algorithm I have found here: https://github.com/JWally/jsLPSolver/ I have created a jsfiddle where I have set up a model and I solve the problem using the algorithm above.…
Noobster
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Why do all Simplex Noise algorithms have a Permutation & Gradient table?

I've been trying to implement Simplex Noise for about a month now, and I do understand the idea of working with Simplices to reduce the amount of calculations needed and also safe power on the gradient side. Implementing this into any language…
Jeroen
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