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James Tursa

Last seen: 1 día ago Active since 2007

Interested in external applications, mex & engine applications with Fortran, C, C++, etc, particularly in the areas of speed improvement and memory management efficiencies.

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I want to convert vector into matrix with all possible combinations
I think John D'Errico answered this some time ago, or a question very much like this. But I can't find his post at the moment. I...

alrededor de 9 horas ago | 0

Can compare between vector and array
Does this do what you want? Finds the row numbers in A that match x. find(all(A==x,2))

alrededor de 10 horas ago | 0

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Modify off diagonal elements of Matrix without looping
You could use logical indexing to get at the off-diagonal elements. E.g., A(~eye(size(A))) = skalar;

alrededor de 10 horas ago | 0

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How to get two 16-bit numbers from a 32bit number
E.g., to split a uint32 into two uint16 you can use typecast( ): result = typecast(your_variable,'uint16') This result will co...

1 día ago | 0

pass a vector from matlab to a c++ program
This really depends on what your C++ program does, but the simplest approach is to use a mex routine. You will need a supported ...

4 días ago | 0

Write multiple variables from a function
Maybe something like this does what you want, with each qq1 and qq2 2D page results in the first two dimensions. [m n] = size(s...

12 días ago | 0

In an assignment A(I) = B, the number of elements in B and I must be the same.
" And in the work space y2 is 3x1 and d is 1x1 " Then d - y2 will be 3x1. You can't assign a 3-element vector to a 1x1 scalar w...

13 días ago | 0

After the if statement is ran why is the answer 10?
A=1; : if A<0 A is not negative, so the body of the if-test never runs.

18 días ago | 0

Solve nonlinear 2nd order ODE numerically
You can look at the examples for ode45( ) here: https://www.mathworks.com/help/matlab/ref/ode45.html?searchHighlight=ode45&s_ti...

20 días ago | 1

The input function does not work well
Pass in a vector using the square brackets. E.g., binary_to_decimal([1 0 0 1 1 0])

21 días ago | 0

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Concatenate logical/numerical arrays element wise
Here is one way: % Generate sample data H{1} = rand(2,3)<0.5; H{2} = rand(2,3)<0.5; H{3} = rand(2,3)<0.5; Hc = cat(3,H{:}) ...

21 días ago | 2

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What is the difference between " while 1" and "while true", Should I use one over the other?
1 is a double class scalar and true is a logical class scalar, so the check for "non-zero" is slightly different for each even t...

23 días ago | 0

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I have a 4 Dimensional Matrix and i want to get its transpose
Maybe this does what you want, which is transpose the first two dimensions: permute(val,[2 1 3 4]) Or you could use this funct...

28 días ago | 0

How to multiply a 3d array with a 2d matrix?
It would be best if your 2D pages were the first two dimensions. That way the 2D pages are contiguous in memory and you can use ...

alrededor de 1 mes ago | 1

Error in concatination in binary values
c1=[8 14 10 9 6 3 2 7 6 11 6 3 13 15 6 0]; NewR = c1(1:2:end)*16 + c1(2:2:end)

alrededor de 1 mes ago | 0

Increased time for setting elements in sparse matrix
Every time you change the elements of a sparse matrix, MATLAB has to deep copy all the existing elements to a newly allocated ch...

alrededor de 1 mes ago | 1

How to run a Matlab file which uses functions from .c and .dll files?
It appears that this may be an older mex routine? Is there a "mexFunction" in the c file? If so, maybe you can just recompile it...

alrededor de 2 meses ago | 1

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Unable to perform assignment because the left and right sides have a different number of elements.
Why are you replacing the sin(y-c) term with approximations? Why haven't you just programmed it as is? It appears you have done ...

alrededor de 2 meses ago | 0

Applying runge kutta for coupled equations
What are and ? Why don't they have differential equations associated with them? Can you give more details about this? Also, it...

alrededor de 2 meses ago | 0

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How to create a loop on function handle
Isn't this just a standard matrix*vector multiply? E.g., XI = @(xi) xi - (y(i,:) + A*((t(i)+c*dt).*xi)*dt); Note that this fun...

alrededor de 2 meses ago | 1

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Index Matrix A and Matrix B Problems
You can use logical indexing: B(A==1) = 0; You can use a loop for this also, but you would have to show us the code you used b...

alrededor de 2 meses ago | 1

Whole derivation of two variable differential function
Please show the code you are using. y' means derivative of y with respect to x, not derivative of y with respect to y. You sho...

alrededor de 2 meses ago | 0

How do i compile multiple fortran code from matlab command
To pass variables from MATLAB to your Fortran code you would typically do the following: Write a single gateway routine in a se...

2 meses ago | 0

Updating Sparse Matrices every Time-Step Efficiently
To specify the sparse matrix size when creating it, use the following syntax: sparse(I,J,K,m,n) where m is the number of rows ...

2 meses ago | 0

how to move a row
result = M([1:400,801,401:800,802])

2 meses ago | 1

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How to set specific size of a figure with exportgraphics?
This doesn't answer your question about controlling exported sizes, but you might be interested in the following export_fig FEX ...

2 meses ago | 0

Renaming the variabel while Symbolic to function handle conversion with matlabFunction
You could keep your existing code and create another function handle: funcv = @(A,xdata,ydata)func(A(1),A(2),xdata,ydata)

2 meses ago | 0

Making an Array out of another Array if conditions are met
You don't need a for-loop for this. The best way is to use logical indexing. See this link: https://www.mathworks.com/help/matl...

2 meses ago | 0

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