Answered
Slice (Or contour) 3D function (in polar coordinate) transformed into cartesian coordinate
https://de.mathworks.com/matlabcentral/answers/95796-how-do-i-create-a-contour-plot-in-polar-coordinates

4 years ago | 0

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Answered
Which solver should I use to solve a square and symmetric, linear system of equations?
R = chol(A); x = R\(R'\b) I don't know if it's faster than the usual \.

4 years ago | 0

Answered
Finding the perimeter of a 2D ellipse using composite trapezoidal integration
The arclength of a curve in parametrized form C = ((f1(t),f2(t)) ,a<=t<=b) is given as integral_{a}^{b} sqrt(f1'(t)^2+f2'(t)^2...

4 years ago | 0

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Answered
Help needed for below error
Since it seems that you only solve for a single unknown, change x2 = [0 1.73]; to x2 = 1.73; Then your code should be for ...

4 years ago | 0

Answered
How to write cumulative product function
m = 10; v = [1 1 2:m]; pcum = cumproduct(v) function pcum = cumproduct(v) n = numel(v); pcum = zeros(n,1); pcum(1)...

4 years ago | 0

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Answered
How would you solve the Pohlhausen solution for Pr=1 using Runge Kutta "RK" once values of the "f" function have been found from the Blasius solution like my code below?
for i = 1:N k1(i,:) = [f(i,2); f(i,3); -(f(i,1)*f(i,3))/2; f(i,5); -Pr/2*f(i,1)*f(i,5)]; k2(i,:) = [f...

4 years ago | 0

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Answered
How to use fmincon to minimize a function with equations and experimental data
In my opinion, you should reconsider your approach completely. For suggested values for A_WE and A_EW from the optimizer, you c...

4 years ago | 0

Answered
Accessing estimated parameters from nlinfit for weighted regression
Use "lsqnonlin" and define the functions f_i as f_i = (ydata_i - F(beta,xdata_i))/sigma(beta,xdata_i) "lsqnonlin" is the solve...

4 years ago | 0

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Answered
How to solve: Error using symengine 'Unable to convert expression containing symbolic variables into double array.'
vf=fz/dpi*Z_total*N; vc=2*ri*pi*N/1000; p00=0.01949; p10=0.5988; p01=-0.0001006; p20=-4.164; p11=4.871e-05; p02=-2.923e-0...

4 years ago | 1

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Answered
why am I recieving the error - Unexpected output of PDEFUN. For this problem PDEFUN must return three column vectors of length 2. ?
function [pl,ql,pr,qr] = pdebc(xl,ul,xr,ur,t); % Boundary Conditions pl = [0;0]; ql = [1;1]; pr = [0;0]; qr = [1;1]; end i...

4 years ago | 0

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Answered
Solving an equation with different inputs
n = 2.4; ALPHA = 0:0.01:0.28; c0 = 1.0; for i = 1:numel(ALPHA) alpha = ALPHA(i); f = @(c) alpha +(1-c).^n - c*n.*(1...

4 years ago | 0

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Answered
License Manager Error -96
https://de.mathworks.com/matlabcentral/answers/95122-why-do-i-get-license-manager-error-96

4 years ago | 0

Answered
How to create angle projection on matrix, for this case matrix dimension (16x32)
You mean PF = exp(1I*angle(A)); ? If not, please give a link to a site where it is explained so that we can understand.

4 years ago | 0

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Answered
How to solve this ode equation where one of the inputs has some delay and equation has written in matrix form in MATLAB ode45?
Order the complete list of time instances when the control variables change their values. If these times are 0 < t1 < t2 < t3 <...

4 years ago | 1

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Answered
How can i graph these equations?
https://de.mathworks.com/help/matlab/ref/fimplicit3.html

4 years ago | 0

Answered
Solving Differential Equations With
fe=2; Qsie=0.05; me=32000; ce=2*Qsie*(2*pi*fe)*me; ke=me*(2*pi*fe)^2; [t,x] = ode45(@(t,x)SMD(t,x,me,ce,ke,tt,Ft),[0 Tmax],...

4 years ago | 1

Answered
I want to comapre my A,B and P against time and want to compare my ODE89 function with Eulers method with a timestep of 3600
A1 = 1; B1 = 3; P1 = 0; ti = 0; tf = 12*3600; Yb = 1; Yp = 0.15; K = 5*10^-5; h = 3600; timestep = [3600 1800 900 450 2...

4 years ago | 0

Answered
How to determine the exact intersection between line and two curves
Depending on how you interpolate between the points of the blue curve, you will get different intersection points. So there is ...

4 years ago | 0

Answered
How to solve system of non-linear equations over a range of "V" values?
Vi_array = [51.5000 59.2250 66.9500 74.6750 82.4000 90.1250 97.8500 105.5750 113.3000 121.0250 128.7500]; x0 = ...

4 years ago | 0

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Answered
Non linear multiple curve fitting
Form a big matrix A: First column: a vector of 1's Second column: log(gamma) or log10(gamma) (depending on what "lg" means) ...

4 years ago | 0

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Answered
what's that means that 'demoplot 1' is inconsistent with its previous use or definition
n = 10; x = 1:n; y(1) = 0; y(2:n) = cumsum(x(2:n).^2); demoplot1(x,y) function [] = demoplot1(x,y) plot(x,y); ylabe...

4 years ago | 0

Answered
How to solve an implicit handle function with two variables?
I = @(V) -I0 + lambertw(I0*R*exp(I0*R+V))/R;

4 years ago | 0

Answered
Need to contour plot from an Nx3 matrix with first 2 columns as points on X-Y plane and the 3rd column as the values to be plotted. I'm getting Z must be at least a 2x2 matrix
See https://de.mathworks.com/help/matlab/math/interpolating-scattered-data.html Section Interpolating Scattered Data Using gr...

4 years ago | 1

Answered
Adding delay to a system of differential equations using the Heaviside function
tau = 1.0; fun1 = @(t,y) y(1); tstart = 0.0; tend = tau; tspan = [tstart,tend]; y0 = 1; [T1,Y1] = ode...

4 years ago | 0

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Answered
How can I set bounds for ga that change with the values of the optimization variables?
Instead of using the array lb and ub, you will have to prescribe such bounds that depend on the solution variables in the Constr...

4 years ago | 0

Answered
double for loop and integral
m=1.24; w_n=55; w=0.7*w_n; zeta=0.05; td=2*pi/w; P_0=1; t=[0:0.1:100]; for ii=1:length(t) f_t(ii)=2*P_0*t(ii)/td; ...

4 years ago | 0

Answered
Error in inline expression
f = @(h) 8*abs(9*acos(3 - h/3) - (3 - h).*sqrt(6*h - h.^2)) - 100 or f = @(h) 8*abs(9./cos(3 - h/3) - (3 - h).*sqrt(6*h - h.^2...

4 years ago | 0

Answered
Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters.
h=3600; A0=1; B0=3; P0=0; K=5*10^-5; Yb=1; Yp=0.15; t = 0:0.1:10; fyt = @(t,y) [(-K*y(1)*y(2)); (-Yb*(K*y(1...

4 years ago | 0

Answered
Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters.
Y(1) is a scalar (single number), 1:numel(t) is a vector. You can't set a scalar to a vector. Use an unused variable name inste...

4 years ago | 0

Answered
Choice of algorithm for mixed-integer-continuous variables optimization problem
I'd call fmincon 199 times for k=2,3,4,...,200 and choose the result for K which gives a minimum for the cost function.

4 years ago | 0