SA-W

Last seen: 3 mesi fa | Attivo dal 2021

Followers: 0 Following: 0

Statistica

Feeds

Domanda

differentiable approximation of bandwidth in ksdensity for optimization
I have an optimization loss term ||x* - y||^2 where x* corresponds to a quantile approximated via ksdensity (e.g., x* = ksdensit...

5 mesi fa | 1 risposta | 0

1

risposta

Domanda

Most efficient way to vertically concatenate numeric data?
In the profiled output picture below, mergedDataPerRank is a cell array storing 53 double matrices with size (6300, 33). Using v...

5 mesi fa | 0 risposte | 0

0

risposte

Domanda

nonlinear spline fit with unknown upper bound of interpolation domain
I want to fit the interpolation values of a spline, but I can not provide a good guess for the upper bound of the interpolation ...

7 mesi fa | 1 risposta | 0

1

risposta

Domanda

starting vector (zero vector) equals lower bounds but gets projected to non-zero vector
I created a small example where I created a start vector euqal to the lower bounds, so the start vector respects the bounds, tho...

11 mesi fa | 2 risposte | 0

2

risposte

Domanda

scale/normalize parameter vector for optimization
In my optim problem, the parameters naturally vary by several orders of magnitude because they represent interpolation values ...

11 mesi fa | 3 risposte | 0

3

risposte

Domanda

transform linear inequality constraints into bound constraints for optimization solvers
Suppose there are linear inequality constraints and are the parameters optimized by fmincon, lsqnonlin, or friends. Since lin...

11 mesi fa | 2 risposte | 0

2

risposte

Domanda

wait for several system calls to finish
I am calling three external programs and can only continue in the matlab program after all programs are finished. Each of them w...

oltre un anno fa | 2 risposte | 0

2

risposte

Domanda

uniform knot vector for splines
Suppose we have uniform interpolation points, e.g x = [1 2 3 4 5 6] The functions for knot generation produce knots of the for...

oltre un anno fa | 1 risposta | 0

1

risposta

Domanda

express basis spline derivative in terms of interpolation values
x = [1 2 3 4 5]; y = randn(size(x)); f = spapi(5,x,y); fdd = fnder(f, 2); If we evaluate the second derivative at a given po...

oltre un anno fa | 1 risposta | 0

1

risposta

Domanda

steps to convert spline from B-form to pp-form (fn2fm)
x = [3.0,4.5,6.0,7.5,9.0,12.0,15.0]; y = [0 0.0343653 0.0694232 0.105143 0.141178 0.246013 0.630537]; f_bm = spapi(5, x, y); ...

oltre un anno fa | 1 risposta | 0

1

risposta

Domanda

spapi: why slvblk instead of backslash operator?
% data x = [3.0,4.5,6.0,7.5,9.0,12.0,15.0]; y = [0 0.0343653 0.0694232 0.105143 0.141178 0.246013 0.630537]; xq = linspace(...

oltre un anno fa | 1 risposta | 0

1

risposta

Domanda

distribution of interpolation points in spline interpolation
rng("default") n = 10; x = linspace(1,10,n); xi = linspace(min(x), max(x), 1e3); y = rand(length(x)); pp = csape(x,y); % in...

oltre un anno fa | 1 risposta | 0

1

risposta

Domanda

cubic spline interpolation - mixed boundary conditions possible?
We need two boundary conditions. Is it possible to specify the first and second derivative at the same boundary point? In csap...

oltre un anno fa | 3 risposte | 0

3

risposte

Domanda

Interpolation schemes that produce positive second derivatives of the interpolant
Given a set of x-values and y-values. The interpoland to this data should have non-negative second derivatives, allowed to be di...

oltre un anno fa | 5 risposte | 0

5

risposte

Domanda

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',...

quasi 2 anni fa | 1 risposta | 1

1

risposta

Domanda

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...

quasi 2 anni fa | 1 risposta | 0

1

risposta

Domanda

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...

quasi 2 anni fa | 1 risposta | 0

1

risposta

Domanda

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 ...

quasi 2 anni fa | 1 risposta | 0

1

risposta

Domanda

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...

quasi 2 anni fa | 2 risposte | 0

2

risposte

Domanda

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...

circa 2 anni fa | 1 risposta | 0

1

risposta

Domanda

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; ...

circa 2 anni fa | 1 risposta | 0

1

risposta

Domanda

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...

circa 2 anni fa | 1 risposta | 0

1

risposta

Domanda

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....

circa 2 anni fa | 1 risposta | 0

1

risposta

Domanda

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...

circa 2 anni fa | 1 risposta | 0

1

risposta

Risposto
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...

circa 2 anni fa | 0

Domanda

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-...

circa 2 anni fa | 1 risposta | 0

1

risposta

Domanda

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...

circa 2 anni fa | 2 risposte | 1

2

risposte

Domanda

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...

circa 2 anni fa | 3 risposte | 0

3

risposte

Domanda

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...

circa 2 anni fa | 0 risposte | 0

0

risposte

Domanda

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...

oltre 2 anni fa | 2 risposte | 1

2

risposte

Carica altro