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Xh Du


Last seen: ongeveer 2 jaar ago |  Active since 2015

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Try to save structural variable, but not everything is saved
Hi all, I ran my code for a few hours and now I get some results. I'd like to save these data to a .mat file such that I can ...

meer dan 7 jaar ago | 1 answer | 0

1

answer

Question


Is it faster to operate a sparse matrix than a dense one when they have the same size?
Hi all, Imagine I have 2 same size matrices, both takes only the upper triangular part and sparse, their sparsity is like thi...

meer dan 7 jaar ago | 2 answers | 0

2

answers

Question


How to recover a square matrix from its upper triangular cell part?
Hi all, I'd like to compute the upper triangular part only for a symmetric matrix in a block by block way. After some operat...

meer dan 7 jaar ago | 1 answer | 0

1

answer

Question


Put elements into corresponding locations of upper triangular matrix
Hi all, Imagine I have a vector: inpt = (1:6)'; Now I'd like to put elements of inpt in the upper triangular part of ...

meer dan 7 jaar ago | 2 answers | 0

2

answers

Question


How to compute the indices of a square matrix?
Hi all, Imagine I have indices: i, j, k, l, I write for i = 1:1 for j = 1:1 for k = 1:2 for l = 1:2 ...

meer dan 7 jaar ago | 2 answers | 0

2

answers

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Operations for calculating l1 and Frobenius norm
Hi all, Imagine I have 2 same-length vectors, u1 and u2, and e = u1 - u2. I'd like to calculate 1. l1 norm of e; 2. Frobenius...

meer dan 7 jaar ago | 1 answer | 0

1

answer

Question


Fprintf: how to automatically move to a new line when reach end of screen?
Hi all, I have something like this: clear; clc; for i = 1:100 fprintf('%d', i) end Here I use fprintf to...

meer dan 7 jaar ago | 5 answers | 0

5

answers

Question


How to plot the l2 norm circle?
Hi all, I'm trying to visualize the l2 norm circle. It seems easy but I'm stuck. This is the code I write to plot the circle ...

meer dan 7 jaar ago | 1 answer | 0

1

answer

Question


Concatenate cell array along one dimension
Hi all, I have a cell array like this: cellA = [12x2 double] [12x2 double] [12x2 double] [12x2 doub...

meer dan 7 jaar ago | 1 answer | 0

1

answer

Question


Extract and realign cells into new cell
Hi all, I have a cell array 'cellA' which contains cell: cellA = {2x1 cell} {2x1 cell} {2x1 cell} {...

meer dan 7 jaar ago | 1 answer | 0

1

answer

Question


Optimize RAM cost by only storing upper triangular part of a symmetric matrix?
Hi all, I have some symmetric (almost dense) matrices which I wish to store only the upper triangular part such that I can op...

meer dan 7 jaar ago | 2 answers | 0

2

answers

Question


Lagrange interpolation in 2D?
Hi all, I'd like to find the interpolating polynomials on a 2d domain. Imagine we have sample points (x1, y1), ... ,(xn, ...

meer dan 7 jaar ago | 1 answer | 0

1

answer

Question


MATLAB killed in Linux
Hi all, I'm running my code with a elasto-dynamics model, which has 300 degrees of freedom and 300 time steps, and this probl...

meer dan 7 jaar ago | 0 answers | 0

0

answers

Answered
Dynamically update cell without clearing previous content?
solution: 'a' can be dynamically updated without special treatment: clear; clc; nr = 1; a = cell(1); for i...

meer dan 7 jaar ago | 0

| accepted

Question


Dynamically update cell without clearing previous content?
Hi all, I'd like to dynamically update cell content and size, without clearing the previous cell content. Check the following...

meer dan 7 jaar ago | 1 answer | 0

1

answer

Question


How to plot solid tetrahedrons in MATLAB?
Hi all, I have information of a mesh including coordinates of nodes and connectivity, how can I plot solid tetrahedrons in MA...

meer dan 7 jaar ago | 2 answers | 0

2

answers

Question


Any recommendations for 3d FEM toolboxes in MATLAB?
Hi all, I have a finite element mesh including nodes and connectivity imported from Abaqus, which looks like this: >> ca...

meer dan 7 jaar ago | 0 answers | 0

0

answers

Question


Variable size: does it reflect real size after computation finishes?
Hi all, I have a program which produces a 40227 by 50 double matrix. I'd like to optimize storage so I want to check total me...

meer dan 7 jaar ago | 2 answers | 0

2

answers

Question


Built-in functions VS explicit loops: which is faster in MATLAB?
Hi all, I did some speed tests with implicit functions and explicit loops, both repeat 1000 times and calculate average time....

meer dan 7 jaar ago | 0 answers | 0

0

answers

Question


Avoid for loops, use cell operation
Hi all, I've asked this question before but didn't get satisfied answer, so I'll change the way of asking. Say I have an ...

meer dan 7 jaar ago | 1 answer | 0

1

answer

Question


Avoid for loops, use cell operation to do: r2' * r1 * l1' * l2
Hi all, Say I have 2 simple 1-by-2 cells, I'd like to perform operation like this: r2' * r1 * l1' * l2 to obtain a 2-by-2 mat...

meer dan 7 jaar ago | 0 answers | 0

0

answers

Question


Surface plot with semilog z-axis: how to keep the same axis limit for iterative plots?
Hi all, I have an algorithm which generates 4 surfaces iteratively. I'd like to set the z-axis to semilog scale and keep the...

meer dan 7 jaar ago | 1 answer | 1

1

answer

Question


How to only perform the upper triangular part of matrix operations?
Hi all, I'm trying to solve this problem, where I have to use a nested loop like this: clear; clc; demo = zeros(4, 4)...

meer dan 7 jaar ago | 1 answer | 0

1

answer

Answered
How to avoid repeated computation when the result is a symmetric matrix?
Guess answer is in the comment, credit: Adam. https://uk.mathworks.com/matlabcentral/answers/332568-how-to-avoid-repeated-com...

meer dan 7 jaar ago | 0

| accepted

Question


How to avoid repeated computation when the result is a symmetric matrix?
Hi all, When obtaining a symmetric matrix, we know that we only need to compute and store the elements of upper triangular pa...

meer dan 7 jaar ago | 1 answer | 0

1

answer

Question


Cellfun to extract arrays from multi-dimensional cell
Hi all, Imagine I have a 2-d cell, each cell element is a m by n matrix, I apply SVD on each element such that they are decom...

meer dan 7 jaar ago | 1 answer | 0

1

answer

Question


Cell in cell in cell...... versus multiDimensional cell
Hi all, Imagine now I have some data to be stored, say there are 24 matrices I need to store. I have 2 choices: 1. use cel...

meer dan 7 jaar ago | 2 answers | 0

2

answers

Question


How to use savefig to save .fig to a specific location?
Hi all, I'd like to use savefig to save .fig files to a specific location, such as: savefig('test.fig') to here: ...

meer dan 7 jaar ago | 1 answer | 0

1

answer

Question


How to find out the dependency of functions?
Hi all, For a function, I'd like to find out which scripts and functions are calling it. For example, there is a function: ...

meer dan 7 jaar ago | 2 answers | 0

2

answers

Question


How to communicate among objects from different classes in a solid way?
Hi all, This is a really long question, thanks for your patience! Imagine I have two classes like this: classdef beam...

meer dan 7 jaar ago | 1 answer | 0

1

answer

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