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How do I plot a multivariate piecewise continuous function?
Why don't you write a simple function for F with 4 if-statements for the 4 cases ? function value = F(x,y) if x ... && y ......

4 years ago | 0

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Solving a 6th order non-linear differential equation in Matlab
I think that nobody in this forum will dive into selfmade software if there are well-tested MATLAB alternatives. So these few l...

4 years ago | 1

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Periodic Boundary Conditions with pdepe
It is possible to use PBC with pdepe? No, sorry.

4 years ago | 0

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Algorithm / Function to find weighting of parameters how influens on result
Seems exactly the opposite from what you presume is true: w = [5 4 9;2 3 0]\[80;30] [0 0 9;10 10 0]*w

4 years ago | 0

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function input to solve ODE
% solve u'(t) = F(t,u(t)) where u = [u1(t), u2(t), u3(t)]' % using forward euler method % Initial conditions and setup neqn...

4 years ago | 0

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I want to simulate the following programme on pdepe solver with third type inlet boundary of Heaviside nature with t0 = 140 days and a zero flux ourlet boundary
pl = ul - C0 * ( 1 + exp(-2*k*t0) )/( 1 + exp(2*k*(t-t0)) ); ql = 0.0; I suggest you plot the function f(t) = C0 * ( 1 + exp...

4 years ago | 0

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Subtraction between a matrix and a column vector
B = A - x where A is your matrix and x is your vector.

4 years ago | 1

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Having problem with a infinite double sum
You might want to try a numerical solution: a = 2.0; b = 4.0; nu = 20; q0 = 1.0; X = linspace(-2*pi,2*pi,250); Y = linspac...

4 years ago | 1

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Trigonometric functions using dsolve
fun = @(t,theta) [1+sin(theta(2))-theta(1);1+theta(3)-theta(2);theta(2)-theta(3)]; theta0 = [0.1, 0.3, 0.2]; tspan = [0,2*pi] ...

4 years ago | 0

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convert matrix to array
A = A(:)

4 years ago | 0

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Not enough input arguments from a row vector
function x = myquad(vec) a = vec(1); b = vec(2); c = vec(3); if b^2 - 4*a*c > 0 x = 2; else if b^2 - 4*a*c =...

4 years ago | 1

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Answered
How can I define a lower bound of the LP?
A = [1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0;... 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ...

4 years ago | 0

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Can this be integrated within MATLAB?
syms XC0 beta zeta f = XC0*zeta*(zeta+sym('1e-9'))^2/(zeta+sym('1e-9')+beta*XC0)^2 intf = int(f,zeta,0,1) Output: 2 ...

4 years ago | 0

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Solving a highly non linear equation in Matlab
It's "only" an ODE of degree 6. Rewrite it as a system of first-order ODEs. You will need 6 initial or boundary conditions. De...

4 years ago | 0

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How can I resolve this problem?
The arrays "Ppost" and "ex" don't have the same number of elements. This has the effect that "ex" has less elements than the v...

4 years ago | 1

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reordering matrix elements according to another matrix
[A,index] = sortrows(A) B = B(index,:)

4 years ago | 0

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error with the integral of a imaginary array
L=integral(g,-Inf,Inf,'ArrayValued',true);

4 years ago | 0

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Fitting a curve on normalized histogram
You can directly calculate the distribution of Z from the distribution of X and plot its PDF. Or do you only have a discrete nu...

4 years ago | 0

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Numerical Solution to second order coupled system of boundary value equations
Use MATLAB's bvp4c.

4 years ago | 0

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How to find all cycles of specified length of given graphs?
Find all cycles and evaluate their lengths afterwards separately: https://de.mathworks.com/help/matlab/ref/graph.allcycles.html...

4 years ago | 0

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How to solve 2d steady state PDE? Temperature is a function of radial and axial direction
Use MATLAB's "pdepe" and interprete the axial coordinate z as the time coordinate t.

4 years ago | 0

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Proper way to write ode45
The usual way is to use arrays in which you can write and from which you can read variables at certain positions. Or you can us...

4 years ago | 1

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Answered
fminbnd not working for a single variable optimization problem
k1=fminbnd(@(k)valfun3(k,k0,z0,a0),kmin,kmax); instead of k1=fminbnd(@valfun3,kmin,kmax);

4 years ago | 0

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Answered
What to do with for-while loop?
number_on_dice = 6; bu = [ ]; while number_on_dice ~= 8 u = rand(); number_on_dice = sum(cdf <= u) + 1; bu = [b...

4 years ago | 0

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Help regarding below question.
f = @(x) [functional equation] syms x df = diff(f,x); df_fun = matlabFunction(df); x = xstart:0.01:xend; % define interval ...

4 years ago | 0

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Why ode45 returns NaN for a system of differential equations?
N = 10; Mi = zeros(N,1); c0 = zeros(N,1); Mi(1) = 14.01; c0(1) = 0.7809; Mi(2) = 16; c0(2) = 0.2095; Mi(3) = 39.95; c0(3...

4 years ago | 0

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calculate the rectified value
built_in_value = mean(abs(A(:)))

4 years ago | 1

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How to code a nonlinear vector-valued function so that it fits the coordinate grids (xq , yq) of triangles?
Here is the author's homepage: https://people.sc.fsu.edu/~jburkardt/ Just contact him.

4 years ago | 0

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Answered
Index in position 1 is invalid. Array indices must be positive integers or logical values. Error in explicitftcs (line 28) u(Nx+1,k) = 1.; >> u(Nx+1,k) = 1.; Index in
Nx should be the number of grid points in x-direction, not the length of these intervals. You mixed this up by setting Nx = 0.1...

4 years ago | 0

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Extract positive value from solve function
If a and b contain no more symbolic constants, then you can use a = double(a); b = double(b); a = a(abs(imag(a)) < 1e-6); b ...

4 years ago | 0