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creating a matrix using integers and other matrices
Exactly what you have already written: c = [1,2,a;3,4,b]; What am I missing?

casi 8 años hace | 0

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mxMakeArrayComplex() what's for?
If it is your own low level code creating and manipulating the mxArray variables, then I agree with you that this function proba...

casi 8 años hace | 0

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ODE45, differential equation
Remove the quotes from 'k', and be sure to define k before you call ode45. Also, ode45 is an initial value problem solver, so th...

casi 8 años hace | 0

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Sparse and binary mask
Try this simple C mex routine. It avoids the overhead you are creating with your sparse alternate stuff. Could maybe be improve...

casi 8 años hace | 2

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Create array with same number
See this link for a discussion of various methods to do this: <https://www.mathworks.com/matlabcentral/answers/51411-initiali...

casi 8 años hace | 6

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thread safety of mx mex functions
Here is my short novel on this topic ... To understand how dimensions are stored in mxArray variables, it will help to review...

casi 8 años hace | 3

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Create a For Loop
Simply adjust your expectations of how to use indexing. E.g., let S(1) mean the same thing as S0 S(2) mean the same thin...

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What does "Error: ()-indexing must appear last in an index expression" mean?
You need to use multiply operators between the ( ) expressions to multiply them. MATLAB does not do this automatically. E.g., ...

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how can i generate a random number between two float numbers
This is one of the examples in the rand doc: val = mnval + rand*(mxval-mnval);

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Is there a faster way to change zeros to ones and ones to zeros?
Assuming you have *only* 0's and 1's in your array, here is another way that also keeps the class of the result as uint8: A...

casi 8 años hace | 3

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A fast way to perform sparse matrix-free product with a vector
Assuming the vectors are 3-tuples of row, column, and value, and that all of the variables involved are full double vectors, her...

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How do I make a function?
You can use a function handle for this. E.g., F = @(n) P*(1+i).^n I'll leave it to you to plug in appropriate values an...

casi 8 años hace | 0

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Populating values across a cell
There is nothing in your loop body that uses the index pp other than the data_pro{pp} assignment, so every data_pro{pp} is going...

casi 8 años hace | 0

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[1 1 2 2 3 3] --> [11 22 33]?
Start with this outline: x = your initial variable of values [m,n] = size(x); result = zeros(___,___); % <-- you fil...

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Mex inplace change problems R2015b and later
One potential workaround is to change an element of the variable after the assignment to force a deep copy. E.g., >> x = 1...

casi 8 años hace | 1

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Undefined reference to mexPrintf for simple helloworld program
Your code is a standard mex routine that can be compiled and run at the MATLAB command line prompt as follows: mex hellowor...

casi 8 años hace | 0

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Newton Raphson equation trig functions
Instead of doing all of this as symbolic, it would probably have been simpler to use function handles and work in double. That b...

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Assembly of matrices using for loop
Read each individual file into a cell array element, then vertically concatenate the cells all at once.

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Cross Product is Returning Values way to small to be right
Your vectors are parallel to each other, so the answer *should* be 0. The small number you are getting is just from floating po...

casi 8 años hace | 1

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Angle between 2 quaternions
Assuming these represent attitude rotations from one coordinate frame to another, if you are simply asking what is the minimum r...

casi 8 años hace | 1

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I want to make a programming function in which I want to take input any mathematical function like f(x)=sin(x)+x^2. then I take a input x and my function return a value of f(x).but i don't know how can i do?
E.g., s = input('Input a function of x: ','s'); f = str2func(['@(x)' vectorize(s)]); Now you have a vectorized functi...

casi 8 años hace | 0

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mexGetData() outputs zeros
1) Your check on prhs[1] requires that it is a double, but your pointer is to a float. So that mismatch will never work. f...

casi 8 años hace | 0

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How to pass a 3d array double[][][] from java to a Matlab function
As long as it arrives as a 3D variable but the dimensions seem backwards, perhaps you only need to permute it. E.g., x = 3D...

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In MEX, how do I populate an array within a struct within plhs?
I don't have MATLAB or a C compiler handy at the moment, but here are some suggestions: 1) Don't make assumptions with API fu...

casi 8 años hace | 0

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Do two instances of MATLAB share a workspace?
Just open up two different instances of MATLAB ... they will be two separate processes with two completely independent workspace...

casi 8 años hace | 3

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Sparse matrix and savings
I don't fully understand your pseudo code, particularly your use of value when indexing into Pattern_Matrix(value). If you just ...

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Query regarding a sparse complex matrix
The minimum data storage requirement formula for a double m x n sparse matrix with nnz non-zero elements, including the index da...

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Concatenate dynamical variables [A1;A2;A3.A4;AN) in one script line
Best advice is to back up and rewrite the code that is creating these A1, A2, etc variables in the first place. Instead, use som...

casi 8 años hace | 1

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Matrix is singular to working precision.
If a square matrix has rows or columns that are very nearly the same, then yes this would cause the matrix to be singular to wor...

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How Can I solve a system of eight exponential equations?
E.g., h = 0:7; A = bsxfun(@(x,y)exp(x*y*pi*1i/8),2*h',h); % Form your equation matrix y = [0.2165 0.8321 0.7835 0.582...

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