質問

How to vectorize or speed up ODE solver with vector ?

I would like to vectorize or speed up ODE solver with vector E? This is extremely slow following this routine. nTime ...

3年以上 前 | 0 件の回答 | 0

質問

How to take FFT inside ode function ?

Matlab is solving ode point by point in t . I want to take FFT inside the function myode. It can taken outside but the way I...

3年以上 前 | 0 件の回答 | 0

質問

How to properly take derivative of discrete data ?

Taking derivative of discrete data requires some fitting and then using the b-form of the polynomial. How to make a 'good' fi...

3年以上 前 | 0 件の回答 | 0

質問

How to make arrows in quiver plot visible ?

How to make the arrows some what more proportional and look like arrows ? The matrices are attached. A = load(A.m...

4年弱 前 | 1 件の回答 | 0

質問

How to select element of matrix that is created with function handle ?

Let say we have matrix defined as A = @(a,n) [a 1 2+1i n*a; 0 1 3+n*1i a; a^2 0 1 a; a 0 0 a]; M1 = @(a)eye(4,4); f...

4年弱 前 | 2 件の回答 | 0

質問

How to find zeros of determinant having complex parameter ?

How to find the zeros of the determinant of 4x4 matrix M which is multiplication of N complex square matrices An containing para...

4年弱 前 | 1 件の回答 | 0

質問

How to solve (find zero) of nonanalitical function fzero or fsolve ?

I have a vector y(x) that does not necessarily have point on y = 0 axis (and is not analytical function). How can I solve (f...

4年以上 前 | 1 件の回答 | 0

質問

How to implement conformal transformation that wrap 2D image around a circle?

How to transform rectangular image to image that is bent at certain radius? On the plot the center line follows the radius whic...

4年以上 前 | 1 件の回答 | 0

質問

How to find the index of the closest value to some number in 1D array ?

How to find the index in 1D array that has closest value to some number ? val =-1.03 val1 = 1.04 x = -10:0.009:10 ...

4年以上 前 | 2 件の回答 | 0

質問

How to integrate the following function ?

<</matlabcentral/answers/uploaded_files/27869/dn.jpg>> How would you integrate this function ignoring the rect ? dx dz a...

4年以上 前 | 0 件の回答 | 0

質問

Could exponent of an array be inproved in speed ? Maybe mex file with exp function (reduced accuracy) for windows 64 bit.

Could this line of code be improved in speed ? MM is an array 512x512^2 elements. MM =ones(512^2,512); tic; exp(1i*(MM)...

4年以上 前 | 1 件の回答 | 0

質問

Could you please compile this as mex for windows 64 bit ? I can not run the compiler. Faster exp function with reduced accuracy.

Code for Exp function with reduced accuracy. I can not compile it. Code from <https://www.mathworks.com/matlabcentral/news...

4年以上 前 | 1 件の回答 | 0

質問

How to vectorize sum of scaled matrices ? Or is there matlab function for irregular inverse dft ?

I am trying to inverse transform function on irregular grid. Is there matlab function for irregular inverse dft ? I would...

4年以上 前 | 1 件の回答 | 0

質問

How to call element from vector out of t = @(theta) x*cos(theta)-y*sin(theta);

x = linspace(1,10,10); y=x; t = @(theta) x*cos(theta)-y*sin(theta); t(0.1) will give me vector. How to get element 5 ...

4年以上 前 | 1 件の回答 | 0

質問

How to vectorize loop of fft ?

How to vectorize a for loop of fft ? clear all W = ones(1,100)*1.5; y(1:200,1:100) = 0.3; ...

4年以上 前 | 1 件の回答 | 0

質問

How to store 1x3 vectors in (n,m) position of 2D matrix in a for loop ?

How to build nested array of 1x3 vectors in the (n,m) posision of 2D matrix in a for loop? And then how to access the n,m vec...

4年以上 前 | 0 件の回答 | 0

質問

Phase retrieval via SDP (semidefinite program)

I would like to have phase retrieval of test picture 2D let say phantom X = phantom('Modified Shepp-Logan',200); X =...

5年弱 前 | 0 件の回答 | 0