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How to Apply Multiple BC Types (Dirichlet, Robin, Neumann) on a Single 3D Face?
Here is one way to create the geometry such that you can set different boundary conditions on different faces at the top. If yo...

9 Monate vor | 0

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Cap Maximum ODE solve time
Josh Meyer's answer shows you one possible way to do this: https://uk.mathworks.com/matlabcentral/answers/511547-possibility-to...

9 Monate vor | 1

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Please help me to plot surface figure. I want to draw this attached photo 2 dimension of (NG,etta) in 3 dimension as (NG, R,etta)
proj() function sol= proj clc;clf;clear; global n; global s %Relation of base fluid rhof=997.1*10^-3;kf=0.613*10^5;cpf=4...

9 Monate vor | 0

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How do I delete specific parts of a graph
The arclength of a function will always be increasing. Thus your graph cannot be the arclength of a function. clear, clc syms ...

9 Monate vor | 1

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How can I calculate the power spectral density of a gaussian pulse?
Here is another one: https://uk.mathworks.com/matlabcentral/answers/169376-power-spectral-density-two-approaches

9 Monate vor | 1

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Please help me. I want to run this attached simple code
Use function dy= projfun(x,y) and replace m by x in the function. Further, b5 and a are undefined. Further, you miss a multi...

9 Monate vor | 0

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Positive Roots of bessel functions.
As I understand your question, given l, you try to find 0 < x_1 < x_2 < x_3 < ... < x_m that makes J_l(x_i) = 0 for i = 1,2,......

9 Monate vor | 0

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Can we find derivative of bessel functions in matlab directly?
You can compute it symbolically first and insert the result as a numerical expression in your code. syms x diff(besselj(0,x),x...

9 Monate vor | 0

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Problem with fit Model with odd order polynomial
In the case of the polynomial of degree 5, the design matrix is rank-deficient: T = readmatrix("DistortionTab...

9 Monate vor | 0

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Doubt of Linear Algebra self-paced course
Why don't you copy it from the course and use it in future ? Or use "quiver" resp. "quiver3": figure(1) quiver([0,0] ,[0,0], ...

9 Monate vor | 0

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How to use arrayfun with built-in Matlab functions where the variable parameter is passed with 'Name', 'Value'?
x=[ 6.9100 6.1800 6.0500 5.7900 5.5000 5.2400 4.9800 4.6800 4.5100 4.6191 5.2582 5.9801 6...

9 Monate vor | 0

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MNPBEM Error - Issue with dot product in tripolygon file
The variable "edge" does not seem to have a substructure with name "pos". E.g. s = 2; s.pos will give this error message. ...

9 Monate vor | 0

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Please help me to run this code
Note that you plot y(1,:), not y(6,:). If I were you, I'd simply use "plot" to compare the three curves depending on Gr. proj(...

9 Monate vor | 0

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Convert a decimal approximation to exact value symbolically
Here, you need the fact that y2-y1 is an odd function: syms x y y1=sin(pi*x/2); y2=x; x1=-1; x2=1; A=2*int(y2-y1,x,x1,0)

9 Monate vor | 0

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solving system of equations
This works, but I doubt it will work in all possible cases. % Tolerance for convergence check tol = 1e-8; max_iter = 100; it...

9 Monate vor | 0

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first order PDE , verification of one solution
You shouldn't waste your time here with symbolic manipulations. What is important is that solutions f(x,y) of the PDE df/dx + ...

10 Monate vor | 0

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Interp1 is not working after applying unique because of rounding off
https://uk.mathworks.com/help/matlab/ref/uniquetol.html

10 Monate vor | 0

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(Error using vertcat) Dimensions of arrays being concatenated are not consistent
x and y are of size 1x500, phix(:,a)' and phiy(:,a)' are of size 1x8. So either x and y had to be of size 1x8 or phix(:,a)' and ...

10 Monate vor | 1

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Symbolic integration: error
Here is one possible implementation: syms x y r u = ((x-1+r)^2+y^2-r^2)*(y^2-r^2/(1-2*r)*x^2); du = gradient(u, [x,y]); du2 ...

10 Monate vor | 0

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Change ode time step based on state
An easier way is to choose appropriate absolute and relative tolerances to reduce the error of the integration: options = odese...

10 Monate vor | 0

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Odefun returns a vector of length 1, but the length of initial conditions vector is 4.
Use function ydot = noMoonGrav(t, y) instead of function [t, ydot] = noMoonGrav(t, y)

10 Monate vor | 1

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Symbolic calculation with solve command
Use S = solve(eqns,[k1 k2 k3],'MaxDegree',4) instead of S = solve(eqns,[k1 k2 k3])

10 Monate vor | 1

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Display data in a while loop as a table
clear, clc format longg f=@(x) x^3-5; df=@(x) 3*x^2; [n,X,Y] = newtonimproved_4_7(f,df,1,0.00001); t=table((1:n).',X',Y'); ...

11 Monate vor | 1

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Constraints to a Second Order Curve Fit
x = [150, 190, 400, 330, 115, 494].'; y = [1537, 1784, 3438, 2943, 1175, 4203].'; C = [x.^2,x,ones(numel(x),1)]; d = y; lb =...

11 Monate vor | 0

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How to express constants of integral
MATLAB's "int" only returns one possible antiderivative. If you want to show the free integration constants, you could use "ds...

11 Monate vor | 2

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solve set of inequalities and plot the solution
A = [-0.0664057051742095,0.0900076050430003;... 0.147476397055133,0.160063987615969;... -0.122381054306963,0.1252339...

11 Monate vor | 0

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Fitting exponential using derivatives
As far as I understand, your model is a differential equation dr/dt = a*1.5^(c+d)*(5-r)^c*(3-r)^d, r(0) = r0 with unknown para...

11 Monate vor | 0

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Apply boundary condition (upper and lower limit) to parameters during the fitting using the function nlinfit?
If you restrict parameters by imposing upper and/or lower bounds, a statistical analysis of the results like that offered by "nl...

11 Monate vor | 0

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The problem is that when I use vpa(U(x,t), 7) to get the solution with 7-digit decimal precision, MATLAB still outputs a very long and complicated expression. how do I fix it?
The documentation says xVpa = vpa(x,d) uses at least d significant digits instead of the value of digit...

11 Monate vor | 0

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how to solve 2DOF linear time variant differential equations in matlab with non-diagonal mass, stiffness and damping matrixes
x0 = [0;0;0;0]; tspan = [0 13.28]; [T,X] = ode45(@fun,tspan,x0); for i = 1:numel(T) dxdt = fun(T(i),X(i,:)); q1ddot(i) ...

11 Monate vor | 1