2,995 total contributions 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.

Answered

How can I see the filter function implementation code at MATLAB?

In general, if the function has an associated .m file then TMW is willing to show you that much. Also there may be information ...

How can I see the filter function implementation code at MATLAB?

In general, if the function has an associated .m file then TMW is willing to show you that much. Also there may be information ...

2 days ago | 1

Answered

If else problem for year

All of those if-elseif blocks make the code difficult to read, and difficult to debug as well. I would advise against that appr...

If else problem for year

All of those if-elseif blocks make the code difficult to read, and difficult to debug as well. I would advise against that appr...

2 days ago | 0

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Answered

Please how can I store all my matrix?

Maybe use a cell array: channel{i} = [importdata(location)]; Then at the end you can work with the individual matrices as chan...

Please how can I store all my matrix?

Maybe use a cell array: channel{i} = [importdata(location)]; Then at the end you can work with the individual matrices as chan...

3 days ago | 1

Answered

Fast Elementwise Matrix-Multiplications

The element-wise times operation in MATLAB is already multi-threaded. You are not going to beat it by writing your own low leve...

Fast Elementwise Matrix-Multiplications

The element-wise times operation in MATLAB is already multi-threaded. You are not going to beat it by writing your own low leve...

5 days ago | 0

Answered

Defining velocity over particular time frame

You don't need a loop for the velocity. Assuming I understand that you want the velocity to be linear, you just need a vector t...

Defining velocity over particular time frame

You don't need a loop for the velocity. Assuming I understand that you want the velocity to be linear, you just need a vector t...

6 days ago | 0

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Answered

Converting C++ bits packed int** to MATLAB unisgned char mxArray using mex?

Some issues: 1) The signature of mxCreateNumericArray according to the doc is: mxArray *mxCreateNumericArray(mwSize ndim, cons...

Converting C++ bits packed int** to MATLAB unisgned char mxArray using mex?

Some issues: 1) The signature of mxCreateNumericArray according to the doc is: mxArray *mxCreateNumericArray(mwSize ndim, cons...

8 days ago | 0

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Answered

Find an optimal solution for a linear system with two inequations

The way you have this problem posed, and assuming by "binary" you mean integer, it can be solved by simple inspection. The max ...

Find an optimal solution for a linear system with two inequations

The way you have this problem posed, and assuming by "binary" you mean integer, it can be solved by simple inspection. The max ...

9 days ago | 0

Answered

How to formulate the random matrix between real interval?

See the second example in the rand doc here, and use your endpoints of 0.10 and 0.50 instead of the example endpoints of -5 and ...

How to formulate the random matrix between real interval?

See the second example in the rand doc here, and use your endpoints of 0.10 and 0.50 instead of the example endpoints of -5 and ...

9 days ago | 0

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Answered

Complex matrix inversion using LAPACK in MEX

I took your code and modified it to be a mex routine that takes a 2D double complex input (caution: no argument checking done!) ...

Complex matrix inversion using LAPACK in MEX

I took your code and modified it to be a mex routine that takes a 2D double complex input (caution: no argument checking done!) ...

9 days ago | 0

Answered

Simulation of irrational numbers

The random number generators that come with MATLAB have very long periods. You can simply use them to form your ratio and it wi...

Simulation of irrational numbers

The random number generators that come with MATLAB have very long periods. You can simply use them to form your ratio and it wi...

16 days ago | 0

Answered

Printing out the element values in a mxDouble array (C++ script in Matab)

%d is a decimal integer format for use with short, int, long, etc. This doesn't work with floating point. Try e.g. %f or %g inst...

Printing out the element values in a mxDouble array (C++ script in Matab)

%d is a decimal integer format for use with short, int, long, etc. This doesn't work with floating point. Try e.g. %f or %g inst...

16 days ago | 0

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Answered

Runge-Kutta function

Here is some code to get you started. It receives a string from the user for a derivative function of x and t and turns it into...

Runge-Kutta function

Here is some code to get you started. It receives a string from the user for a derivative function of x and t and turns it into...

18 days ago | 1

Answered

for loop continued fraction

Yes, you can use the formula x(n) = 1 + 1/x(n-1) if you want to use a loop. Just start with x(1) = 1.

for loop continued fraction

Yes, you can use the formula x(n) = 1 + 1/x(n-1) if you want to use a loop. Just start with x(1) = 1.

18 days ago | 0

Answered

How to sum up multiple vectors, element by element, to recieve one final value?

The numerator is just a simple dot product between two vectors, and the denominator is just a simple sum. Using the fact that a...

How to sum up multiple vectors, element by element, to recieve one final value?

The numerator is just a simple dot product between two vectors, and the denominator is just a simple sum. Using the fact that a...

18 days ago | 1

Answered

Creating a 2D random walk

In this logic, you will never get to the y branches because one of the first two x branches will always be true: if p_x<0.6 ...

Creating a 2D random walk

In this logic, you will never get to the y branches because one of the first two x branches will always be true: if p_x<0.6 ...

19 days ago | 0

Answered

Is Walter Roberson a real person, or is he some kind of Matlab AI robot?

Blade Runner 2019 ...

Is Walter Roberson a real person, or is he some kind of Matlab AI robot?

Blade Runner 2019 ...

19 days ago | 1

Answered

single precision simulation of internal calculations

" Is there a way to set Matlab to perform all calculations (even internal) to single precision? " Not the way you are probably ...

single precision simulation of internal calculations

" Is there a way to set Matlab to perform all calculations (even internal) to single precision? " Not the way you are probably ...

19 days ago | 0

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Answered

How do i convert this for loop into a while loop?

This for loop: for i=1:n % stuff end is equivalent to this while loop: i = 1; while i <= n % stuff i = i + 1...

How do i convert this for loop into a while loop?

This for loop: for i=1:n % stuff end is equivalent to this while loop: i = 1; while i <= n % stuff i = i + 1...

19 days ago | 1

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Answered

How can I vertically concatenate cells?

I don't have much of a clue what you really need, but maybe this will give you a start on the MATLAB cell array syntax (with the...

How can I vertically concatenate cells?

I don't have much of a clue what you really need, but maybe this will give you a start on the MATLAB cell array syntax (with the...

23 days ago | 0

Answered

Functions, Error check

From your description, it seems like you simply need to test for the number of characters. E.g., while numel(outstring) == 0

Functions, Error check

From your description, it seems like you simply need to test for the number of characters. E.g., while numel(outstring) == 0

24 days ago | 0

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Answered

How to implement such function?

Basically, just replace f(x) with f. E.g., f = constant; : f = coeffVector(i) * cos(i*x) + f; You could also do this wit...

How to implement such function?

Basically, just replace f(x) with f. E.g., f = constant; : f = coeffVector(i) * cos(i*x) + f; You could also do this wit...

24 days ago | 0

Answered

How to from I(x) to permutation and from permutation to I(x)

E.g., >> Per Per = 0 1 2 3 0 2 3 1 0 3 1 2 3 2 0 1 ...

How to from I(x) to permutation and from permutation to I(x)

E.g., >> Per Per = 0 1 2 3 0 2 3 1 0 3 1 2 3 2 0 1 ...

26 days ago | 0

Answered

case of two mappings

Not sure which one is first, but maybe one of these is what you want? >> mapping1 = [0 1 3 2] mapping1 = 0 1 3 ...

case of two mappings

Not sure which one is first, but maybe one of these is what you want? >> mapping1 = [0 1 3 2] mapping1 = 0 1 3 ...

26 days ago | 0

Answered

what wrong about this error

The error message appears when you have a mismatch in the number of elements on the rhs and the number of elements on the lhs. E...

what wrong about this error

The error message appears when you have a mismatch in the number of elements on the rhs and the number of elements on the lhs. E...

26 days ago | 0

Submitted

mxGetPropertyPtr & mxSetPropertySDC C-mex functions

Fast memory efficient alternative to API functions mxGetProperty & mxSetProperty.

26 days ago | 10 downloads |

Answered

Why is subtracting different sized matrices not giving me an error? What is matlab calculating?

See documentation on "implicit expansion" https://www.mathworks.com/help/matlab/matlab_prog/compatible-array-sizes-for-basic-op...

Why is subtracting different sized matrices not giving me an error? What is matlab calculating?

See documentation on "implicit expansion" https://www.mathworks.com/help/matlab/matlab_prog/compatible-array-sizes-for-basic-op...

27 days ago | 0

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Answered

store values from loop in an array

Typos in your code: for i=1:length(A) And change tableA to TableA (MATLAB is case sensitive). Or, you could get rid of the l...

store values from loop in an array

Typos in your code: for i=1:length(A) And change tableA to TableA (MATLAB is case sensitive). Or, you could get rid of the l...

27 days ago | 0

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Answered

Combination of X and Y vectors to get all possible positions on a Cartesian plane

[XX,YY] = ndgrid(X,Y); Z = [XX(:),YY(:)];

Combination of X and Y vectors to get all possible positions on a Cartesian plane

[XX,YY] = ndgrid(X,Y); Z = [XX(:),YY(:)];

27 days ago | 0

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Submitted

C Mex MATLAB Version

Mex C code to determine MATLAB version at compile time and run time

27 days ago | 10 downloads |