Community Profile # SA-W

Last seen: 3 dagen ago Active since 2021

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fmincon optimization: is the first order optimality very sensititve to changes in the step tolerance?
I use fmincon interior-point algorithm to fit parameters to a pde. Here are my basic settings: opts = optimoptions('fmincon',...

12 dagen ago | 1 answer | 1

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Question

parfor chuncks: are loop iterations running in parallel WITHIN a chunck on local machine?
I know that parfor does load-balancing to break the loop iterations into chuncks which are then sent to the workers. Demo exam...

20 dagen ago | 1 answer | 0

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Question

global optimization in parallel in combination with external pde solver
I use MultiStart from the global optimization toolbox to run lsqnonlin solver for a bunch of start vectors. I want to run the l...

21 dagen ago | 0 answers | 0

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Question

matlab uitable: split columns into several rows
I construct an uitable from a struct like: % params is a struct T = struct2table(params); fields = fieldnames(params)'; fig ...

3 maanden ago | 1 answer | 0

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Question

graphical visualization of input parameters collected in a struct/array
My simulation depends on a whole bunch of input parameters that control various features of the simulation. I decided to group...

3 maanden ago | 2 answers | 0

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Question

vectorize expression containing if statement
A = [-5 3 2;2 3 4; 3 5 6; -2 8 9]; %compute product of columns in a vectorized fashion A(:,1).*A(:,2).*A(:,3); %calculate the...

5 maanden ago | 1 answer | 0

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Question

tall array introduces significant overhead if I call gather() at every iteration in a loop
I want to figure out the spread of the invariants of a symmetric 3x3 matrix using the code below %input nPts = 2; ub = 2.0; ...

5 maanden ago | 1 answer | 0

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Question

out-of-memory because of large array: tall array as a workaround?
Given a symmetric, positive definite 3x3 matrix (6 independent components), I want to figure out the spread of the first and sec...

5 maanden ago | 1 answer | 0

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Question

how can I increase the performance of this loop?
nPts = 15; a = linspace(0.1, 2.0, nPts); b = linspace(0.1, 2.0, nPts); c = linspace(0.1, 2.0, nPts); d = linspace(-0.3, 2....

5 maanden ago | 1 answer | 0

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Question

scatteredInterpolant: what is linear interpolation in 2d?
%coords supportPts = [3 3; 3.3 3; 3 3.25; 3.3 3.25; 3.6 3; 3.6 3.25; 3 3.5; 3.3 3.5; 3.6 3.5]; %values Fval = [0 0.1121 0.064...

5 maanden ago | 1 answer | 0

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can I pass these nonlinear constraints to lsqnonlin?
residual =[residual; smallnumber*[diff(G,2);diff(H,2)]] This is an equivalent way to implement my suggestion I just realize th...

5 maanden ago | 0

Question

c++ engine API: minimal example gives segmentation fault, see stacktrace
I built an c++ API engine using a minimal example as shown here https://de.mathworks.com/help/matlab/matlab_external/test-your-...

6 maanden ago | 1 answer | 0

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Question

bilinear extrapolation based on interp2
[X,Y] = meshgrid(0:10); Z = X.^2 + Y.^2; [Xq,Yq] = meshgrid(0:0.25,10); V = interp2(X,Y,Z,Xq,Vq,'linear'); I want to use int...

6 maanden ago | 2 answers | 1

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Question

can I pass these nonlinear constraints to lsqnonlin?
Let denote a function of two variables and the parameters of the optimization problem which I want to solve with lsqnonli...

6 maanden ago | 3 answers | 0

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Question

symbolic differentiation to find analytical expressions that are time-consuming to calculate manually?
Given a function of two variables f(x,y) = I want to find the analytial expression of the determinant of the Hessian of . ar...

6 maanden ago | 0 answers | 0

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Question

lsqnonlin optimization: large condition number of Jacobian matrix at all iterations, but full rank
I use lsqnonlin to solve a non-linear data-fitting problem (fitting parameters of a partial differential equation). The minimiza...

6 maanden ago | 2 answers | 1

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Question

source code of multistart in global optimization toolbox
I am currently using multistart to perform optimization with multiple start vectors. ms = Multistart(...) ... = run(ms,...) ...

7 maanden ago | 1 answer | 0

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Question

import bubblechart in latex document and typeset text (x-labels,...) by latex -- possible?
I created two bubblecharts next to each other in a tiledlayout(1,2) and want to include it in my tex document. Both matlab2tikz...

9 maanden ago | 1 answer | 0

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Question

gradient of bubble colors in a bubble chart
I want to create a bubblechart with three different bubble colors. One group of bubbles is red, the second group is blue, and ...

9 maanden ago | 1 answer | 0

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Question

natural cubic spline interpolation of y-values: how to get derivative of the spline wrt the y-values?
Given a data set with support points x_1,...,x_n and corresponding y-values y_1,...,y_n. My objective is to create a cubic spli...

9 maanden ago | 3 answers | 0

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Question

optimization: have function return NaN but not at initial point
I use fmincon interior-point algoritm to solve my optimization problem. Based on Matlab's recommendation, I let my function re...

9 maanden ago | 1 answer | 1

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Question

is the objective function stochastic (-> use something like patternsearch) or deterministic?
My objective function is given by f(x) = ||d^sim(x) - d^exp||^2 d^exp is a constant vector of measurements, to which I add ra...

9 maanden ago | 1 answer | 0

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Question

what is a reasonable step tolerance for optimization algorithms if parameters are in the range [0,1]?
My parameters are bounded from below by zero and from above by roughly one. I recently worked with a quite small step tolerence...

9 maanden ago | 1 answer | 0

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Question

fmincon: any way to enforce linear inequality constraints at intermediate iterations?
I am solving an optimization problem with the interior-point algorithm of fmincon. My parameters have both lower and upper boun...

9 maanden ago | 3 answers | 1

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Question

alternatives to gradient-based optimization algorithms like lsqnonlin that handle at least O(10) parameters?
I am fitting parameters of a PDE to experimental data utilizing the function lsqnonlin from the optimization toolbox. I obser...

10 maanden ago | 2 answers | 0

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Question

trust-region reflective algorithm in lsqnonlin and fmincon: same behavior for "unconstrained" optimization"?
Say I provide constraints to lsqnonlin and fmincon. For both, I will choose trust-region-reflective algorithm Do both fmincon a...

10 maanden ago | 1 answer | 1

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Question

multistart optimization: local run index of solutions found by [...,solutions] = run(__)?
I am running my optimization problem with several start vectors utilizing the function [x,fval,exitflag,output,solutions] = run...

10 maanden ago | 1 answer | 0

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Question

importdata produces strange output when reading a textfile with blank cells and text
I want to import the attached file which is the result of matlabs function run. As you can see, there are a couple of blank cell...

10 maanden ago | 2 answers | 0

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Question

lsqnonlin with multiple start vectors: continue with next start vector if the function computing the objective function sets a "flag"
I want to execute lsqnonlin with multiple start vectors by iterating over a for-loop. If the function called by lsqnonlin (here,...

10 maanden ago | 2 answers | 0