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James Tursa


3,084 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.

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Answered
How to return the outputs of mexFunction() in Matlab?
Put this at the bottom of your code. But remember that if you call mexErrMsgTxt your mex function will exit immediately and not ...

약 6시간 ago | 0

Answered
Error: Matrix dimensions must agree
You could use V(2:end) or V(1:end-1) instead of V in that line. Or maybe average the two.

1일 ago | 0

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Answered
Write a MATLAB code to estimate the exponential function. Inputs should be x and n. The outputs must include approximate value, true value, error, absolute error, and relative error.
Put your function code for e_to_x() in a separate file called e_to_x.m somewhere on the MATLAB path. Then put your other code t...

2일 ago | 0

Answered
Kindly give me the Matlab code for simplex method?
Use the MATLAB supplied function fminsearch.

2일 ago | 0

Answered
Error when calling the mexFunction
You probably should have gotten a warning from the compiler that your callFun( ) function doesn't return anything, even though t...

2일 ago | 0

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Answered
How to turn assigned vectors into a 3x3 matrix?
Assuming vec3 is a typo, result = [vec1;vec2;vec3]; If you need to, you can transpose the result. If your vec3 is not a typo,...

3일 ago | 0

Answered
[Create mexfunction from C code] The order of several c files
The order you compile your source code files should not matter. The error seems to be that the compiler can't find the resource...

3일 ago | 0

Answered
When I try to run a function in matlab, I get an error, it is undefined
Put this code in a file called checkEchelonMatrix.m that is on the MATLAB path: function [result] = checkEchelonMatrix(M) %res...

3일 ago | 0

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Answered
Memory erased in mex file
I would highly advise combining your multiple mex routines into one mex routine that you call with a directive (e.g., a string) ...

3일 ago | 0

Answered
Sort Index - Bug
The sort index gives the location in the original array of the sorted values. I.e., the sort results "a" are "original_array(sor...

3일 ago | 1

Answered
[Create mexfunction from C code] warning: implicit declaration of function
You call myfunction( ) before the compiler has seen a prototype or definition of myfunction( ). Either move your square( ) and ...

3일 ago | 0

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Answered
How can we create a vector of length n
There are many ways of doing this. E.g., use the ones( ) function and divide by 10. Or use the zeros( ) function and add 1/10....

4일 ago | 0

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Answered
Index Exceeds Matrix Dimensions
You have inadvertantly created variables named "dot" and "cross" that are shadowing the MATLAB functions of the same names. Cha...

4일 ago | 0

Answered
Saving all outputs of for for-loop
Basic steps for you to take would be: Create your range up front, and not as part of the loop indexing. E.g., a t vector Use t...

4일 ago | 0

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Create matrix indicating combinations of dummy variables
Variations of this technique are often used, but this can exceed your memory if n gets too large: n = 8; result = dec2bin(0:2^...

4일 ago | 0

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Answered
Solve the limit limx→0
Hint: If you are just looking to get an answer, consider looking at the Taylor Series of each individual term and then ask yours...

4일 ago | 0

Answered
Filling a matrix without for-loops and ifs
Check out the sub2ind( ) function: https://www.mathworks.com/help/matlab/ref/sub2ind.html?searchHighlight=sub2ind&s_tid=doc_src...

4일 ago | 0

Answered
Vectorizing evaluation of cell array of functions
Not sure this will be any faster since the loop is just hidden, but you can try this: output = arrayfun(@(x,y)x{1}(y),funcell,i...

4일 ago | 1

Answered
Wondering if you have any merchandise for sale cause I'd love to look like a part of the MATLAB team 😀
How about a MATLAB/Simulink Rubik's Cube? https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=matlab+rubiks&_saca...

4일 ago | 0

Answered
Is there a matlab function similar to numpy.spacing
From the numpy.spacing doc: "It can be considered as a generalization of EPS ... there should not be any representable number ...

5일 ago | 3

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Answered
What is the best way to insure that all of my functions are using the same constant values?
I use a function that returns a structure, containing the values and the unit descriptions. Your code can either pass this stru...

5일 ago | 3

Answered
Separate out every fourth element of a Vector
V = your vector result = V; result(4:4:end) = []; % remove every 4th element The above syntax with [] on the rhs is special ...

9일 ago | 0

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Answered
How to extract the value of dydt from ode45 function
Why can't you just call your odefcn( ) function with your solution t and xSol vector elements as inputs (e.g., in a loop)? Does...

9일 ago | 1

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Answered
How to make an assignment for my for loop?
This syntax with the curly braces next to SBOS means it is a cell array: SBOB{ whatever } But this syntax with the dot notatio...

9일 ago | 1

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Answered
Write binary file in Matlab
Can you read and write as “STREAM” in your FORTRAN compiler? No header stuff to worry about.

10일 ago | 0

Answered
how binary floating point to real decimal number representation ?
You can't use dec2bin( ) reliably for this conversion in all versions of MATLAB because it is limited by flintmax (see note at b...

10일 ago | 0

Answered
Binary floating point Representation in Matlab
Did you try it? >> A=[ 0.1900 -0.0300 -0.1300 0 0.1500 -0.0700 0.0500 0.1600 -0.2500 -0.1900]; >> dec2bin(typecast(A,'uint...

10일 ago | 0

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Answered
Find sum of elements in a cell along the columns
Is this what you are trying to do? (using the curly braces) y = sum([A{2,:,1}])

13일 ago | 0

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Answered
Can somebody explain me this answer?
You are using linear indexing into "a". This matrix: >> 3*ones(2) ans = 3 3 3 3 When used as indexing, i...

13일 ago | 1

Answered
Using 3D array to subtract row Q from row P
It is unclear what you really want. If you want the Euclidean distance squared between rows, e.g., rows 1 and 3, then just d =...

15일 ago | 0

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