3,083 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

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.

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.

1 day 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...

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...

1 day ago | 0

Answered

Kindly give me the Matlab code for simplex method?

Use the MATLAB supplied function fminsearch.

Kindly give me the Matlab code for simplex method?

Use the MATLAB supplied function fminsearch.

1 day 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...

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...

1 day 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,...

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,...

2 days 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...

[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...

2 days 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...

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...

2 days 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) ...

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) ...

2 days 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...

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...

3 days 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 ...

[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 ...

3 days 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....

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....

3 days 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...

Index Exceeds Matrix Dimensions

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

3 days 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...

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...

3 days ago | 0

Answered

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^...

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^...

3 days 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...

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...

3 days 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...

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...

3 days 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...

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...

3 days 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...

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...

3 days 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 ...

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 ...

4 days 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...

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...

5 days 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 ...

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 ...

9 days 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...

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...

9 days 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...

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...

9 days 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.

Write binary file in Matlab

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

9 days 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...

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...

10 days 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...

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...

10 days 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}])

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}])

13 days 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...

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...

13 days 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 =...

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 =...

15 days ago | 0

Answered

How to change radians into degrees?

Why are you using sym to find the angle? Just use atand( ) directly with the appropriate input. That seems to be the intent of...

How to change radians into degrees?

Why are you using sym to find the angle? Just use atand( ) directly with the appropriate input. That seems to be the intent of...

16 days ago | 0