Answered
How to numerically calculate volume under the curve?
You have a surface. (Not a curve as I might say.) How do you compute the area under that surface? Simple. Just call trapz twice....

1 month ago | 1

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Answered
ode45 integration issues for some choices of physical parameters,
This is an absolutely classic case for a stiff system, where for some sets of system parmeters, you have two or more things happ...

1 month ago | 0

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How to choose 60 unique coordinates ('A') from 600 coordinates('B'), nearest to 60 other coordinates('C')
As I pointed out to @Voss and @Star Strider, if the points in B mst be unique, then there is an issue. If you simply choose the ...

1 month ago | 1

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finding variable of a given equation
gamma is a really bad choice of variable names, since gamma is itself a very useful function in MATLAB. Try to avoid doing these...

2 months ago | 1

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solving nonlinear equation using newton method
You just misunderstand how to use the exponential function. In MATLAB, e^x is written as exp(x). That makes your fn as: fn = @...

2 months ago | 0

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How to Set a Minimum Step Size for Variables in GA Solver (Global Optimization Toolbox)?
Really easy. Don't think of a step size for the GA solver. It does not take steps anyway, not like fmincon or other solvers of ...

2 months ago | 1

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Answered
Solution of system of nonlinear equations
This will be literally impossible to do in double precision, given the huge dynamic range of those coefficients. But we can look...

2 months ago | 0

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Support with interpolation using interp3 in MATLAB
And ... your question about MATLAB is? Far too much vague verbiage to know what is the problem. If you want to know how to use i...

2 months ago | 0

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Ode45 g and dg
You cannot use the variable dg4, before it is defined. And we see you do this: dg2=m*A+k*g(1)+h1*k*g(3)+dg4 ... dg4=h1*k2x*g(...

2 months ago | 1

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fitting with custom equation
(I assume you intended to write 1/y, and not I/y, where the variable I is not defined.) y = [1.6E5 2.5E5 4.1E5 8E5 1E6 2E6 7E6 ...

2 months ago | 1

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improve fit compared to R
x = [0.858734025700000 0.975248753121875 1.02525125312812 1.13140821289062 1.15927407430000 1.18768630564687 1.21665290240...

2 months ago | 1

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Some .jpeg photos can not be processed by Matlab code.
I've not even looked at your code. But you have jpg images, uint8 code values. So I wonder if adding the code values caused an o...

2 months ago | 0

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Finding concave hull around abstract shape
I don't know the soure of this data. But, can you start with the two pieces as separate entities, form polyshapes from each, and...

2 months ago | 1

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Numerical Integration MATLAB vs Python/VBA
This is difficult to say, because we know virtually nothing. First, does the problem arise from the use of subtly different da...

2 months ago | 0

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Warning: Explicit solution could not be found./ empty sym
Does an analytical solution exist for EVERY equation you can write down? (No.) Even if such a solution does exist, is it certain...

2 months ago | 0

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fmincon is not converge
It is very rarely easy to know why a solver fails to converge on a messy thing like this. But you should never let it come to th...

2 months ago | 0

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Is there any way to perform an at least partially symbolic smulation (using ODE or discrete model) in simulink?
Essentially, no. This is a frequent question about tools like ODE45 too. Simulink is a purely numerical tool, like ODE45 and oth...

2 months ago | 0

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d solve command matlab
syms e P S A t m V0 t0 V(t) real The point being that assumptions can apply only to variables, not functions. V(t) is a functio...

2 months ago | 0

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Plotting data dependent on three independent variables.
Do you have a 4-dimensional holographic monitor? That is, you can plot things in 3-dimensions. You will see a projection into a ...

2 months ago | 0

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vector output of a symbolic vector
syms s X Y Z l1 = X*s - 1 == 3*X + Y + Z + 2/s l2 =Y*s == - X - Y - 1/s^2 l3 =Z*s - 2 == X - Z - (s - 1)/s^2 [Xsol,Ysol,Zsol...

2 months ago | 0

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Optimisation of three function in two variables
There may be an issue here, if you think you can maximize them all simultaneously. The (x,y) coordinates that maximizes one func...

2 months ago | 1

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About fitting one curve with one equation and calculating two values from fitting
Suppose I gave you a set of data, and asked you to tell me two parameters from the data. All I need is one data point, More woul...

2 months ago | 0

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How to fit this model with a Weibull distribution?
If this is data that you think comes from a Weibull, then you do not want to use regression techniques to fit the distribution. ...

2 months ago | 0

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how i can show in matlab tha sqrt(x^2)=x in symbolic toolbox
Except, that equality does NOT hold! The sqrt "function" has two branches. sqrt(x^2) can as easily be -x, as it is x. So you can...

2 months ago | 1

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I keep getting 4 answers per variable in 4x1 sym
L = 225; % Length of the ship in meters B = 32; % Beam of the ship in meters T = 12; % Draft of the ship in meters v = 0.5; %...

2 months ago | 1

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Find zero of simple monotonic function where the independent variable can only be integer
@Michael Albert No. You just THINK there is some obscure MATLAB function to solve your problem. You do not know that to be the ...

2 months ago | 0

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Why is my test accuracy higher than validation accuracy?
Not really. It might be a reflection that you needed more data, that your sets are just not large enough. The law of large numbe...

2 months ago | 0

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Answered
What is happening with the line of best fit here?
StrainStress = [0.00005 010.1; 0.00007 014.3; 0.00011 021.8; 0.00014 027.6; 0.00020 040.0; 0.00030 061....

3 months ago | 1

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Answered
Generating a matrix of 0s and 1s with constrained domains
Are you saying you want to break the matrix into a set of regions, where within the region, the matrix contains zeros, and the r...

3 months ago | 0

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How to provide a positive and negative value for the tolerance value?
Good answer by @Voss of course. I'll merely add a few points of interest. You could just test to see if the current term being ...

3 months ago | 1