Answered
lsqcurvefit to estimate parameters in ODE45
Modifications in the following lines are necessary: [ ... ] = lsqcurvefit(@(theta,t) kinetics(theta,t,precision),...) function...

2 months ago | 0

Answered
How to create a function handle for thermodynamics(semi-infinite heat conduction) using erfc with multiple variables?
Use ./ instead of / in your definition of thetafh. But you are asked to write a function, not a function handle.

2 months ago | 0

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Answered
How to separate real and imaginary value into different column?
A = [real(v),imag(v)]; if v is the column vector with 1024 complex numbers.

2 months ago | 0

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Answered
How to code erf(z) summation series?
function main z = [0.1 0.5 1 2]; for i=1:numel(z) [erfc1(i),n(i)] = myerfc1(z(i)); end erfc_matlab = erfc(z); X = [z.',...

2 months ago | 0

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Answered
How can I solve this partial differentiation equation numerically?
A = zeros(M+1); U2 = zeros(M+1,N+1); A(1,1) = 1; for i=2:M A(i,i-1) = -sigma; A(i,i) = 1+2*sigma; A(i,i+1) = -sigma;...

2 months ago | 0

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Answered
(Solved) Help with please these are hard
function [n,summa] = threshold(limit) summa = 0; n = 0; while summa <= limit n = n+1; summa = summa + 5*n^2 - 2*n; end...

2 months ago | 0

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Answered
Derivative of a function of three variables
syms y S K C(y,S,K) =exp(-y*sqrt(S*K)); g = gradient(C(y,S,K),[y,S,K])

2 months ago | 1

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Answered
Integrate a random function
Matlab tools can not be used for this problem because the integral is not simply a numerical value, but a random variable itself...

2 months ago | 0

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Answered
Solve partial differential equations coupled
There is no matlab code that can solve this problem directly. Look at the CLAWPACK package available in the internet.

2 months ago | 1

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Answered
summing columns based on certain interval
sum(sum(A(1:51,:))) sum(sum(A(53:102,:))) sum(sum(A(104:153,:)))

2 months ago | 0

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How to draw graph of the following function?
function main a = 1; nu = 2; d0 = 0; nu0 = 1; n = 15; deltat = 0.05; % end of user inputs T = 0:deltat:n ; M = [(1-a/nu...

2 months ago | 1

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Answered
How to predict furure values in a non linear regression?
Naive procedure: If your fitting curve depends on time t, evaluate it at the future time instant you have in mind. But be very...

2 months ago | 0

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How to create Matrix of known dimensions with random values?
For random numbers uniformly distributed on [0,1] : A = rand(5,3);

2 months ago | 0

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Calculate perpendicular line to an 3rd order polynomial
For a general function f, the formula for the perpendicular line to the function through (x0,f(x0)) is y = f(x0) + (x-x0)* ( -1...

2 months ago | 0

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Answered
PDEPE coupled boundary condition help
dX^bar/dt = 3/R * D_ap * dX/dr (@r=R) For dX/dr (@r=R) you can insert the right-hand side of your second boundary condition for...

2 months ago | 0

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Answered
Plotting General Solution Of Differential Equation
Maybe sol = dsolve(eq); sols = subs(sol,[C1,C2,C3,C4],[-1,-1,-1,-1]); fplot(sols,[-10,10])

2 months ago | 0

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How to quickly find the indecies of elements in an array?
indices = find(A==B)

2 months ago | 0

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how to arrange x-coordinate w.r.t y-coordinates?
Something like As = sortrows(A); x = As(y(:)+1,1) where y is the vector of y-coordinates ?

2 months ago | 0

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Answered
how to solve this nonlinear equation?
function main p=0.1:0.5:10; gss0 = 1.0; for i=1:numel(p) gss(i)= fzero(@(x)fun(x,p(i)),gss0) gss0 = gss(i); end plo...

3 months ago | 0

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Answered
ode15s and 0de23 very slow at high frequencies
I have no experience with the physical background, but if for low frequencies, the solution somehow looks like sin(0.001*x) and ...

3 months ago | 1

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Answered
Sum of elements of a matrix such that no row or column repeats
p = randperm(n); sum = 0.0; for k = 1:n sum = sum + a(k,p(k)); end where a is the nxn matrix.

3 months ago | 0

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Answered
Index in position 3 exceeds array bounds (must not exceed 1).
You overwrite C when you call contourf.

3 months ago | 0

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Answered
Integrating the results of state space output(ode45)
Alternatively to the solution I suggested previously, you can use Matlab's "cumtrapz".

3 months ago | 0

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potting the integral of a state
If y'(t)=f(t,y) is the state space equation, you get the integral of y by simultaneously solving z'(t)=y(t), z(0)=0.

3 months ago | 0

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How do I write an inductive sequence?
N = 10; % define number of recurrence terms to be calculated x = zeros(N,1); x(1)...

1 year ago | 1

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Answered
substract array elements based on other arrays
setdiff(All,union(R1,R2))

1 year ago | 1

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Answered
Solving large sparse Ax=b with lower bound constraint
Did you try starting from the solution of the unconstraint problem ?

1 year ago | 0

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Answered
dsolve second order differential equation
dySol=diff(ySol,x); dySol(585.8)

1 year ago | 0

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Answered
How to plot graph of value of variable when a parameter is varied
Your equations can only be solved for one value of R, namely R = 0.3 + 0.366*exp(-0.3). This can be seen by dividing equation 1...

1 year ago | 0

Answered
write a function called tri_area returns the area of a triangle with base b and height h
function area = tri_area(b,h) area = 0.5*b*h; end From the command window A = tri_area(3,2)

1 year ago | 3

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