Community Profile

photo

Benson Gou


Smart Electric Grid

Last seen: 7 days ago Active since 2017

Founder, Smart Electric Grid

Statistics

  • Thankful Level 5
  • First Review

View badges

Content Feed

View by

Question


Fast calculate the inverse of a lower triangular matrix
Hello, Everyone, I need to write a code on myself to calculate the inverse of a lower triangular matrix. The matrix is a 3000 ...

2 months ago | 2 answers | 0

2

answers

Question


How can I get the alternatives for the functions Not supported by Matlab Coder?
Dear All, I want to convert my Matlab code into C language using Matlab Coder. But I got the following functions which are Not ...

2 years ago | 1 answer | 0

1

answer

Question


How to quickly calculate the sum of the transpose of a sparse matrix?
Dear All, I have a very big sparse matrix A. I want to obtain the sum of its transpose of the selected columns in A. Here is my...

2 years ago | 2 answers | 0

2

answers

Question


How to quickly do the calculation?
Dear All, I have a code to calculate an array using several arrays. The code is as follows: Ieq1 = Haltmr(mmm(jbb2),IndBus(sol...

2 years ago | 1 answer | 0

1

answer

Question


How to systematically handle a cell?
Dear All, I have an array Measinj. I want to find out the indecies of Lineon whose 2nd or 3rd columns equal to the entry in Mea...

2 years ago | 0 answers | 0

0

answers

Question


How to deal with the structure?
Dear All, I have a struct which saves a number of records. I have the following codes which takes more time than expected. Re...

2 years ago | 1 answer | 0

1

answer

Question


How can I find a faster way to calculate the transpose of a matrix?
Dear All, I have a matrix A and I want to select some columns from A to form another matrix B, and calculate the sum of each co...

2 years ago | 1 answer | 0

1

answer

Question


How to run find function faster?
Dear All, I have an array A with 6000 elements in integers, for example, "10", "12", "5" and others. Actually array A saves the...

3 years ago | 1 answer | 0

1

answer

Question


Can I calculate the inverse of a matrix using arrayfun?
Dear All, I have a sparse matrix A. I want to calculate its inverse. I used the following way to calculate invA. invA = A \ s...

3 years ago | 2 answers | 0

2

answers

Question


How to quickly save a matrix by adding rows?
Dear All, I calculate a row Ai and save it in my defined matrix A using the following way: A = [A; Ai]; But I foud it took a ...

3 years ago | 1 answer | 0

1

answer

Question


How can I quickly obtain the inverse of a square sparse matrix?
Dear All, I have a square sparse matrix A. I use the following way to obtain its inverse: invA = A \ eye(size(A)); I am wonde...

3 years ago | 1 answer | 0

1

answer

Question


How to quickly find the indecis of an array in another array?
Dear All, I have arrays A and B. I want to quickly find out the repeat entries of A in B without using intersect. For example, ...

3 years ago | 2 answers | 0

2

answers

Question


Looking for a way faster than find?
Dear All, I have an array A. I want to find out the index of those "1" entries in the array A. For example, A = [1 2 5 1 3 2 ...

3 years ago | 1 answer | 0

1

answer

Question


How to speed up my code?
Dear All, I found my code spent a lot of cpu time on the following functions: intersect, took 20.11 seconds, called 232074 tim...

3 years ago | 1 answer | 0

1

answer

Question


How to add (combine) together two structures with the same fields?
Dear All, I have two structures A and B with the same fields. How can I combine them together to form a new structure? For ex...

3 years ago | 1 answer | 0

1

answer

Question


How to add more values to an existing structure?
Dear All, I have an existing structure A which has several fields. Each field have 100 values. Now I want to add 20 more values...

3 years ago | 1 answer | 0

1

answer

Question


How to extract some values from a structure?
Dear All, I have a structure A which has several fields. Each field has 100 values. I want to extract the first 20 values from ...

3 years ago | 1 answer | 0

1

answer

Question


how to form a two-column array for a given but dimmension-unknown array?
Dear All, I have two array with the same length A and B. I want to form another array C which is formed by A and B. But the dim...

3 years ago | 2 answers | 0

2

answers

Question


How to apply a function independently for a set of data?
Dear All, I have a set of data {Ai, bi}, i = 1, ..., N. I want to apply a function which solves Ai(xi) = bi, a nonliear problem...

3 years ago | 0 answers | 0

0

answers

Question


How to quickly find out the repeat integers in an array?
Dear All, I have an array A which contains repeat intergers (entries). For example, A = [4 20 5 4 7 5 9 5 31]. I want to find o...

3 years ago | 2 answers | 0

2

answers

Question


How to assign the values to a matrix?
Dear All, I have a zero matrix A whcih needs to be assigned values from an column vector B. The indecies of those elements are ...

3 years ago | 1 answer | 0

1

answer

Question


How to generate a sparse matrix for a given array?
Dear All, I want to generate a sparse matrix B for a given array A. A contains two columns of indecis. For example, A = [1 3;...

3 years ago | 2 answers | 0

2

answers

Question


How to quickly assign the values of a matrix using a given array?
Dear All, I have an array A which contains two columns of integers. I want to build a matrix B in the following way. For exam...

3 years ago | 2 answers | 0

2

answers

Question


How to quickly find the indecies of elements in an array?
Dear All, I have an array A which contains integers. I have another array B. I want to find out the indecis of B in A. For ex...

3 years ago | 2 answers | 0

2

answers

Question


Can Ridge Regression solve my problem?
Dear All, I plan to buy Statistics and Machine Learning Toolbox to apply Ridge Regression to solve my problem. But I do not kno...

3 years ago | 1 answer | 0

1

answer

Question


How to find the CUP time used by each function in my code?
Dear All, I want to know the CPU time used by each function of my code. I donot know if it is possible. I donot want to use tic...

3 years ago | 1 answer | 0

1

answer

Question


Is the C code generated by Matlab Coder Faster than my Matlab Code?
Dear All, I am thinking to buy a Matlab Coder to convert mt Matlab code into C code. My purpose is to largely reduce the CPU ti...

3 years ago | 1 answer | 2

1

answer

Question


How to quickly obtain the row indices in the original matrix A for a sub-matrix B?
Dear All, I have an original matrix A and a sub-matrix which is formed by selected rows from A. Now given A and B, how can I fi...

3 years ago | 1 answer | 0

1

answer

Question


How to efficiently solve a matrix eqation when the matrix is updated?
Dear All, I need to solve a matrix linear equation: Ax = b. I know the most fast way to solve x is x = A\b. My question is: for...

3 years ago | 1 answer | 0

1

answer

Question


How to find out a smallest sub-matrix B from a sparse matrix A which has the equal rank and # of non-zero columns?
Dear All, I have a very sparse matrix A. I need to find out a number of rows (smallest #) of A which satisfies the following co...

3 years ago | 2 answers | 0

2

answers

Load more