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Is FORMAT DEBUG still any useful?
Strange behavior and probably deserves a bug report. E.g., R2019a: >> x = 1; >> y = x; >> x = x + 1; >> format debug >> y...

5年以上前 | 1

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Precision (decimal digits) are very low and digits(32) does not help.
This is likely just a display issue and you don't need the Symbolic Toolbox. MATLAB does regular calculations in full double pr...

5年以上前 | 0

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Consecutive subtraction of the entries of a vector
If A is a row vector: B = [A(1) diff(A)]; If A is a column vector: B = [A(1);diff(A)];

5年以上前 | 0

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generate random number with total sum is 10
Not sure from your wording if you want the row sums to be 1 or 10. If it is 1, then r = rand(6,1); r(:,2) = 1 - r(:,1); Modif...

5年以上前 | 0

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when does changing variable's value affects its structure address?
In addition to what Walter has written, I would point out that all of the rules for variable creation, assignment, and sharing h...

5年以上前 | 0

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Replace the numbers in an array
A(~isnan(A)) = B;

5年以上前 | 1

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Vector ODE using forward Euler method
Also your main code should look something like this: g = 9.8; mu = 0.5; [t,y]=ode45(@(t,y)rhs_1(t,y,g,mu),[0 100],[0.1; 0]); ...

5年以上前 | 1

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unique function return value of duplicate vector entry
Why can't you just use ind1 and ind2? E.g., V1_1 = V1_1(ind1); V2_1 = V2_1(ind1); V1_2 = V1_2(ind2); V2_2 = V2_2(ind2);

5年以上前 | 0

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Insignificant modification of code leads to NaN
Think about what is happening with this loop: for i = 1:num_iterates x = A*x; R(:,i) = x/norm(x); %%%% Problem Line %...

5年以上前 | 1

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Skip instance of a loop with error
Something like this: try fn = x+y+z; %The function is just a representation. I am actually performing a Fi...

5年以上前 | 0

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Performance of applications that are developed in MATLAB versus C++/C
Any such comparison will depend on exactly what computations are in question. A general comparison of languages probably isn't ...

5年以上前 | 4

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Numerical Integration by Matlab
Hint: You might look here: https://en.wikipedia.org/wiki/Normal_distribution Knowing that the integral of the Normal density f...

5年以上前 | 0

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Does MEX compiler (and the associated shared files) automatically ship with all MATLAB distributions of any license type?
Mex routines are not guaranteed to be compatible between different versions of MATLAB, for the very dependency reasons you alrea...

5年以上前 | 1

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function call returns "index (1.2): subscripts must be either integers 1 to (2^63)-1"
You are missing a multiply operator. There is no implied multiplication in MATLAB with the 2( combination. E.g., u_1 = @(y) ...

5年以上前 | 0

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Mex, how to copy an array to output
See the solutions I posted here: https://www.mathworks.com/matlabcentral/answers/702682-with-mxmalloc-and-mxsetdoubles-mex-func...

5年以上前 | 0

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With mxMalloc() and mxSetDoubles(), mex function crash matlab
You have memory leaks in your current code. E.g., tmpResult = mxMalloc(numRows*numRows*sizeof(*tmpResult)); // this memory ...

5年以上前 | 2

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hi I am trying to use this code to solve RK4 equation and I keep receiving this error . what should I do?
Your implementation has several errors: Looks like you are creating i as a vector and then using that for indexing in A(i) You...

5年以上前 | 0

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Filling in multidimensional array efficiently
Something like this maybe? k = 1; % your loop b = r x 1800 matrix f = whatever ch = whatever r = size(b,1)...

5年以上前 | 0

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extract out values out of loop
Make them arrays and assign to the elements. E.g., for i= 1: length(Hi) [XYZ(:,i),H(i),D(i),I(i),F(i)] = wrldmagm(Hi(i),La...

5年以上前 | 1

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Projectile motion with drag. My problem is in the loop as the number of elements are not equal apparently on the left and right. Id appreciate detailed input ive been lost on this for a couple of days now
This makes AccDrag a vector: AccDrag(1,:) = [AccDragX(1) AccDragY(1) 0] So here you have a vector on the right hand side and a...

5年以上前 | 0

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calling another matrix in a matrix
Don't do this! Creating numbered named variables in your code like yakit_1, yakit_2, etc. leads to downstream coding problems a...

5年以上前 | 0

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Newton Raphson Method in a for loop
You don't have the Newton-Raphson method coded correctly. You need to update the x value you use for the delta within the loop ...

5年以上前 | 0

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How to use ode45 to solve a system of two differential equation?
If you don't have the Symbolic Toolbox, here is the procedure: 1) Write your equations in matrix form: F*qdotdot + G*qdot + H*...

5年以上前 | 0

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Multiplication of large matrices
Do NOT transpose your matrix explicitly before the multiply. That will only cause a deep copy, double the memory footprint, and...

5年以上前 | 1

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[Matlab Grader] How to check if the matrix has upper triangular form?
This looks like a display issue. The numbers in the lower triangle are not exactly zero, they just display that way out to 4 dig...

5年以上前 | 0

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Questions about how to plot a summation function with two variables
From the formula image, it appears you need fun( ) to create a matrix z where each element corresponds to the formula for a part...

5年以上前 | 0

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How could I solve this system of ODEs?
For your case, simply start the run at time T and integrate backwards in time to t0. I.e, this is still an initial value proble...

5年以上前 | 1

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Problem when Indexing large integer arrays
This [v(end):-1:v(1)] creates an indexing array that starts at the value v(end), increments by -1, and ends with v(1). It doe...

5年以上前 | 0

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dot product between two different size of matrix
Assuming everything is real and by "dot product" you aren't involving complex conjugates, simply this C = B * A';

5年以上前 | 1

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Multiply one dimension of a 3D Matrix by a vector
C = A .* reshape(B,1,1,[]); For earlier versions of MATLAB that do not have implicit expansion it would be this: C = bsxfun(@t...

5年以上前 | 0

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