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Solve of implicity equations
alpha = 0.14; A = 3300; n = 0.01 ; b_2019 = 69100; rho = 0.02; uno_alpha_A = ((1-alpha)*A); dos_rho = (2+rho); uno_n = (1+n);...

3 years ago | 0

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What am I doing wrong?
ex2d is a function. You call a function, even a function you wrote yourself, by passing in arguments. For example, when you use ...

3 years ago | 0

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Why can't the index variable of a for loop be stored in a structure or other array?
Surely this is not a big problem? for ind = 1:10 status.ind = ind; % do Stuff end

3 years ago | 0

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is there any way to get a 2nd order polynominal through 2 points(each end point)
You want to fit a 2nd degree polynomial through two points? Of course only a straight line would work there through two points, ...

3 years ago | 1

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Is there an option to overwrite the old release when installing a new one?
I'll admit, I typically have 3 to 6 releases, and usually at the high end of that scale. They are useful to me in case I might w...

3 years ago | 0

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Volume of retinal lesion
It seems clear. You have multiple slices. Compute the area of each slice. At that point, you could just sum the area of each sli...

3 years ago | 1

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Plot complex signal with imaginary and complex
n = 2000; t = linspace(0,500,n); Signal = cos(t/10) + i*sin(t/10); % a simple signal, as a function of time. plot3(t,real(S...

3 years ago | 0

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Simplex optimisation using fminsearch
You are still looking for help on this? There is ABSOLUTELY no need to use a simplex optimizer for this problem. NONE AT ALL. L...

3 years ago | 0

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3rd order approximation solving for variable
x = (0.2:0.2:0.8); y = [.3168, .7404, 1.3736, 2.2692]; format long g p = polyfit(x,y,3) So, to within floating point trash...

3 years ago | 0

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General variable creation question
Don't generate a zillion variables. Instead, learn to use arrays. Cell arrays, structs, multi-dimensional arrays. This will leav...

3 years ago | 0

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How can I make a 3d plot with two equations and one variable?
By the way, there is NO reason to define f as symbolic, and then assign the number 0.0405 to f. f is now double preicsion. syms...

3 years ago | 0

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Solving an equation gives me three possible answers. How can I reference only one of these answers?
syms v f eta; f=0.0394; f = 0.0394; eqnvel = (9.801-3.802*v)*v*eta==(((f*200*(pi/4)*0.1^2)/6.434)+((27*(pi/4)*0.1^2)/64.34))*...

3 years ago | 1

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Answered
Expanded use of .* operator
R2016b No need for access. That is when it appeared. Before that, bsxfun was needed. bsxfun appeared in R2007a. Before that, w...

3 years ago | 0

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Problem with convergence using newtons method
First, you CANNOT prove that Newton's method has quadratic convergence using any existing function, or any such piece of code. ...

3 years ago | 0

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How to specify a domain of x and y values for a graph?
Did you read the help for fsurf? What does the second argument do? help fsurf syms x y f = y^2*(...

3 years ago | 0

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Answered
I would like to plot the possible solutions (x, y, z) of the following equation system: dn^2=(x-xn)^2+(y-yn)^2+(z-zn)^2 where n=1 to 3 and dn, xn, yn, zn are known
You have 3 spheres, with known centers and radii. Expand those equations. Then subtract them from each other. So maybe Eq1-Eq2...

3 years ago | 0

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f(x)=0 matlab code for fixed point
You have been given a function f(x), and you now want to write a fixed point solver that will first, automatically create g(x) b...

3 years ago | 0

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Answered
How to prevent MATLAB from using parallel calculations for QR factorization?
https://www.mathworks.com/matlabcentral/answers/103133-how-can-i-limit-the-number-of-computational-threads-used-by-matlab-in-mat...

3 years ago | 0

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How to make a linear regression coefficient algorithm
Why do you want to write your own linear regression code? This is generally a bad idea. Never write code to do what a profession...

3 years ago | 0

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Populating off-diagonal blocks of diagonal matrix and making it sparse
There are several mistakes you seem to be making here, surprising if you have been reading a lot about sparse matrices lately. ...

3 years ago | 0

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lsqnonlin initial conditions (transcendental equation)
This does not make sense. x_data = importdata("x_data.mat"); x_data Your x_data vector is identically constant values. uniqu...

3 years ago | 0

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Philosophical question: How to get a vector from the output of solve? Why isn't it a vector already?
I tried it with a vector, wondering if that might make solve work more easily. And it does work. A = magic(3); X = sym('X',[3,...

3 years ago | 0

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Why does fmincon using the sqp algorithm need a full matrix to specify linear constraints?
This sounds like a good excuse for a feature request to me. However, my gut tells me there is a technical reason in the algorith...

3 years ago | 0

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How to build a function fun that takes as input the matrix A and as output provides the matrix B which is produced out of A in the following ways.
Possibly homework. (I never trust simple problems like this, where the goal is simply to move thigns around in a matrix. They ar...

3 years ago | 0

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How to get numerical values of nonlinear implicit function?
This is far easier then you may think. Um, trivially so. Just solve for t, as a function of y. Pencil and paper suffice for that...

3 years ago | 0

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How to write the equation in matlab I= A A* T² exp (qob/kT) exp (q(V - Rs I /kT)) (exp (-1/n) ? Why is the curve not shown in the drawing?
n=5.2; %Ideality factor A =8.16; %Richardson constant q = 1.602e-19; % electron charge K = 1.380e-23; %Boltzmann constant...

3 years ago | 0

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How to find a point on this plot?
X = [-205078000000000.00 -190430000000000.00 -175781000000000.00 -156250000000000.00 -141602000000000.00 -117188000000000.0...

3 years ago | 0

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Answered
How to find a coordinate of a circle with a given equation tangent to the circle
You (apparently) want to find the circle of radius 4, with center at (0,y0), where y0 is unknown, that is tangent to the curve. ...

3 years ago | 0

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Answered
Fsolve can't solve this simple nonlinear equation
c = 3; eq = @(z) c - (z.^3/3 - z); [xsol,fval,exitflag] = fsolve(eq,0) fplot(eq,'b') hold on plot(xsol,fval,'rs') grid o...

3 years ago | 2

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Answered
Unrecognized function or variable 'imnoise2'.
which imnoise2 -all We cannot help you to use a function that does not exist as part of MATLAB, Possibly, the code you are usi...

3 years ago | 0