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wei zhang


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USTC

50 total contributions since 2016

PHD candidate in life science department

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Question


How could I compile with cuda/thrust library in cudamex?
Hi, I am trying to build a mex with thrust library with the below code. I got an error. C:\Program Files\MATLAB\R2020b\extern\i...

3 days ago | 0 answers | 0

0

answers

Question


Why `sparse` function accumulate large sparse COO format matrix by index so fast?
Hi, I am dealing with "repeated COO format" sparse matrix. I try to "accumulate" it by its index efficiently. I am inspired by t...

6 days ago | 1 answer | 0

1

answer

Question


Could I pass a 'triangulation' class into mex?
Hi, I am trying to use mexcuda to accelerate some code with triangle mesh. I would like to use 'triangulation' class variable a...

8 days ago | 2 answers | 0

2

answers

Question


How to "free" or "destroy" pointer array of mxArray?
Hi, I am using mexCallMATLAB in mex. So I need to construct pointer array for multi input or output. Like the below tmp variabl...

9 days ago | 1 answer | 0

1

answer

Question


How to set all one gpuArray in mex?
Hi, I need to set a all-one double gpuArray. I think I could use mxGPUCreateGPUArray to initial it. But it seems mxGPUCreateGP...

9 days ago | 1 answer | 0

1

answer

Question


How to make two mxArray* scalar multiply each other?
Hi, I have a simple step of multiplying two double scalar variables in mex. Why not the type "mxDouble" support multiply? Must ...

10 days ago | 1 answer | 0

1

answer

Question


How to check the Bytes of gpuArray?
Hi, I am confusing in checking the Bytes of gpuArrays. It seems every varaible's Bytes is 4. Could I do something more to set ...

10 days ago | 1 answer | 0

1

answer

Question


How to change the class of mxArray double to int in c mex ?
Hi, I am trying to convert a double class mxArray to int. I don't know how to do that. My c code is like below. I would like t...

11 days ago | 0 answers | 0

0

answers

Question


Why built-in conjugated gradient solver for sparse linear matrix runs much faster than normal script, no matter GPU or CPU?
I am trying to profile the conjugated gradient method for Ax = b. A is a large sparse matrix. The conjugated gradient method cou...

16 days ago | 0 answers | 0

0

answers

Question


Could I use double precision with `cusparse` or `cublas` function in mexcuda.cu file?
Hi, I am trying to compile my .cu file with cudamex. In this file, I would like to write some functions in cusparse or cublas f...

29 days ago | 0 answers | 0

0

answers

Question


Could I use the `mxGPUArray` format data in the cuda kernel function?
I am new in compiling the mexcuda. I am trying to use the mxGPUArray as inputs of cuda kernel. My sample.cu code is as below. It...

1 month ago | 1 answer | 0

1

answer

Question


How `gpuArray` save sparse matrix when running Preconditioned conjugated gradient?
Hi, I am using cuda in Matlab to accelerate the Preconditioned conjugated gradient evaluation of "Ax = b". I'm glad to find the ...

1 month ago | 1 answer | 0

1

answer

Question


Is there any function like "specgraphhelper" existing in the 2019a or later version?
I had used a scripted named "select3d", which function is to select points in 3d figure. But when I update my Matlab to 2019a. T...

5 months ago | 0 answers | 0

0

answers

Question


Is there any method to accelerate many small matrix and vector's "mldivide" (4*4)?
I am trying to solve many(4000000) mldivide evaluation. All of them are in the form of "x = A\b". A is a 4*4 matrix, and b is 4*...

5 months ago | 3 answers | 0

3

answers

Answered
How to set the constraints of L0- norm in linear programming?
I found an answer to my own question. I transfer the problem to MILP problem. The idea is from stackExchange. If I make anythi...

6 months ago | 0

Question


How to set the constraints of L0- norm in linear programming?
(sorry, I miss the objective function before. I have edited it well) I am trying to set the L0-norm constraints, which give a c...

6 months ago | 3 answers | 0

3

answers

Question


How to set the sum of the absolute value of variables as inequality matrix and vector in linear programming?
I am trying to solve a linear program with command "linprog". The inequality constrains has a sum of varaibles. e.g. I have 3 va...

6 months ago | 1 answer | 0

1

answer

Question


Is there a way to get the max memory used when I run my script?
I am trying to solve a distributed large sparse linear equation. I found the size of the RAM is the limitation of my algorithm. ...

7 months ago | 1 answer | 0

1

answer

Question


What is the cause of the error of "CPARDISO encountered an error in phase 22: Error code = -2."?
I am trying to solve a large sparse matrix equation Ax = b. A is in 700000*700000, and b is in 700000*500. I am using the distri...

7 months ago | 1 answer | 0

1

answer

Question


Is there any way to accelerate the solving of a series of large sparse positive definite linear equations "Ax=b" with same "A" and different "b"?
I am trying to solve a series of the linear equations Ax=b. A is a large sparse positive definite matrix, in n*n. And b is a vec...

7 months ago | 3 answers | 0

3

answers

Question


Is there any method to calculate the inverse of matrix which changed a few values?
I have a large sparse matrix A and have gotten its inverse matrix inv(A) . Then I need to change an element value to get a new m...

7 months ago | 3 answers | 0

3

answers

Question


Is there any way to speed up the function `changem`?
I am doing some substitutions of the index of triangle mesh. After removing or selecting some points on the mesh, I need to "ret...

7 months ago | 2 answers | 0

2

answers

Question


How to set the shadow in the trimesh figure?
I am trying to display surface mesh of the brain in Matlab. I used the delaunayTriangulation object and trimesh function. I need...

7 months ago | 0 answers | 0

0

answers

Question


How to accelerate the process of `find` in large for loop ?
I have two arrays A,B. I want to find the index of every element of B in A. I'm sure that every element of B must appears in A t...

7 months ago | 2 answers | 0

2

answers

Question


Problem with using `reshape` to reorder the matrix.
I am trying to reorder my matrix "by block" in columns. See the code below, it is a mini case of my problem. It only has 2 ...

7 months ago | 2 answers | 0

2

answers

Question


Is it possible to accelerate the speed of saving data into files with parallel way?
I am trying to save data to files, i.e. txt file. The speed is very low. This step takes almost 80% time over my whole script. M...

7 months ago | 2 answers | 0

2

answers

Question


Is there faster way to apply `det` function along the third dimension?
I am trying to calculate the det of many 4*4 matrix. I store the data in a matrix with shape 4*4*n. (n =4000000). I am using the...

7 months ago | 1 answer | 0

1

answer

Question


How to get the diagonal point pairs of a 2D rectangle?
I am trying to find the diagonal point pair of an arbitrary input rectangle. i.e. A = [1,1]; B = [-1,-1]; C = [1,-1]; D = [-...

8 months ago | 1 answer | 0

1

answer

Question


How to make delaunayTriangulation object from points and connectivity in 3D?
I am trying the tetramesh function. Before I plot the tetraheron mesh, I need to store the mesh in an delaunayTriangulation obje...

8 months ago | 1 answer | 0

1

answer

Question


Could `distributed array` accelerate the speed of solving Linear Equations with Iterative Methods?
I am using Iterative Methods, like preconditioned conjugate gradients to solve large sparse linear equations(800,000*800,000). I...

8 months ago | 1 answer | 0

1

answer

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