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eval() is too slow to numerically evaluate a function with X(t) and Y(t).
Something like this? syms X(t) Y(t) Vfun = [2*X + Y ; cos(X)*X^2 + Y^3 ; 3 + sin(Y)] syms x y vfun = subs(Vfun,[X Y],[x y])...

1 year 前 | 0

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I have one column data 57600 points, how can i convert it to 240 by 240 matrix!
x = your column vector result = reshape(x,240,240); or you might need the transpose: result = reshape(x,240,240).';

1 year 前 | 0

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I want to calculate pi^2 to 22 decimal places
You can use this excellent FEX submission by John D'Errico: https://www.mathworks.com/matlabcentral/fileexchange/36534-hpf-a-bi...

1 year 前 | 2

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How to stop running code once conditions are met?
If your Birthday function is supposed to represent only one trial (a reasonable thing to do), then you should be returning n, no...

1 year 前 | 0

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How to fix the must be a column vector error?
You should double check your derivative function. Shouldn't the result be a 4-element column vector that is a function of q? Ne...

1 year 前 | 0

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How to compare elements of two vectors in MATLAB ?
Compare for what purpose? E.g., these statements will compare them: isequal(v1,v2) % are they equal v1 == v2 % matrix of indi...

1 year 前 | 0

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Problem with time steps in Runge-Kutte method
"... I get different results with different time steps ..." In general, that is the expected result. I suppose the real questi...

1 year 前 | 1

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angle2dcm: How to reference direction cosine matrix output?
Does this do what you want: x = zeros(1,m); % reorder these to row vectors y = zeros(1,m); z = zeros(1,m); : xyz = [x;y;z];...

1 year 前 | 0

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Motion equation of a space engin in low earth orbit
As Bjorn has pointed out, your J2 terms are all the same but they should be different because the equatorial bulge affects the z...

1 year 前 | 1

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Problem using 4th order Runge-Kutta method
You have a factor of 2*K4 that shouldn't be there. It should just be K4. E.g., Fx = @(t,x,vx,y,vy,z,vz) [vx; 3*t; vy; t; vz; 7*...

1 year 前 | 0

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How can I find angle between two vectors in 3D ranging from 0 to 360 or -180 to +180?
https://www.mathworks.com/matlabcentral/answers/501449-angle-betwen-two-3d-vectors-in-the-range-0-360-degree

1 year 前 | 0

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Add another column to the right end of this array
your_matrix(:,end+1) = 1.5;

1 year 前 | 0

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Convert Number Character array to Number Integer array/matrix?
Numeric types typically do not get displayed with leading 0's. The numbers you show are converted correctly, they just don't pr...

1 year 前 | 0

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Use strcpy with mxArrayToString ?
char* inputStr2 = strcpy(inputStr2, inputStr); % Not working and causing matlab to crash This line crashes because inputStr2 is...

1 year 前 | 1

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How to find the number of non-NaN elements in a column that are NaN in the last column, in MatLab?
Code is written from a slightly reordered wording: "for each column, number of elements that are NaN in the last column and non...

1 year 前 | 0

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How to call function repeatedly using arrays as variables?
There are other ways do to this, but to answer your question about how to turn the code into a loop, use indexing based on the n...

2 years 前 | 1

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Best Practice: Many Functions relying on Global Variables?
See this link for a related discussion involving the best way to define global constants, in particular Steven Lord's answer: h...

2 years 前 | 1

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已回答
Use Matlab to find the acceleration and jerk of the body with velocity
Take the derivative of velocity to get acceleration. Take the derivative of acceleration to get jerk. Since you have an explic...

2 years 前 | 0

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floating-point arithmetic
"... the IEEE754 conversion of 0.1234 and 0.123 have infinite digits ..." Not sure what you mean by this statement. Neither of ...

2 years 前 | 0

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random number generating RANDI with percentage
One way: n = 1000; p = 0.86; r = rand(n,1); x = r < p; m = sum(x); r(x) = randi([0,14],m,1); r(~x) = randi([15,28],n-m,1)...

2 years 前 | 0

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Points inside the sphere
Just plug your points into the ellipsoid equation and see if they work. E.g., ((x - X)/a).^2 + ((y - Y)/b).^2 + ((z - Z)/c).^2 ...

2 years 前 | 1

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Strange output from symbolic calculation
This isn't strange at all. You are asking the Symbolic Engine to examine all floating point expressions involving pi, which isn'...

2 years 前 | 0

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I keep getting an error?
Generally, these types of problems are solved by extracting the contents of the cell instead of using the cell itself. E.g., C ...

2 years 前 | 0

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3D sparse matrices
You can use the ndSparse FEX submission by Matt J: https://www.mathworks.com/matlabcentral/fileexchange/29832-n-dimensional-spa...

2 years 前 | 0

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Convert Fortran to MATLAB
Here is the equivalent MATLAB code: NB = 100; F = 0; for i=1:NB % [some equations] if( abs(xm) < wm ) ym ...

2 years 前 | 0

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What is the difference between a^3 and a.^3 if a is a matrix?
E = C^3 is a matrix power, equivalent to E = C*C*C, where these are all matrix multiplies. D = C.^3 is element-wise power, wher...

2 years 前 | 2

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Need Help for the rest of this coding
This is very basic vector construction and indexing. I suggest you take the MATLAB Onramp tutorials found here: https://www.mat...

2 years 前 | 0

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Malfunction to my matrix calculation
K .* F (with the dot) does element-wise multiplication with implicit array expansion if the variables are different sizes, thus ...

2 years 前 | 1

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已回答
How do I write this c++ for loop statement in Matlab for loop?
E.g., using a while loop (changed max and min to maxx and minn): x = j; while( maxx >= minn && x <= m+r ) % body of loop ...

2 years 前 | 0

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why my matlab code calculates the inequality wrongly?
Negative numbers are not greater than positive numbers. This is the correct result. What is strange to you about this?

2 years 前 | 0

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