Answered
Plotting a Weibull density function
Try x=0.1:0.1:130; instead of x=0:0.1:130; Best wishes Torsten.

9 years ago | 1

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Answered
coupled ODEs with two variables solver
This is a hyperbolic system of 1st order partial differential equations. If you have the NAG toolbox, there are solvers for t...

9 years ago | 0

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Matlab says that the 'e' is undefined
See the examples under https://de.mathworks.com/help/symbolic/int.html Best wishes Torsten.

9 years ago | 1

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Find the constant of a cubic function
All cubics of the above form with A+B=0.845 have f(0)=0 and f(1)=0.845. A and B are not uniquely determined b...

9 years ago | 0

Answered
How to solve simultaneous Partial Differential Equation
These are ODEs, not PDEs. Use a solver from the ODE-suite (e.g. ODE15S). Best wishes Torsten.

9 years ago | 0

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Answered
Solving differential equation containing independent function
The example "ODE with Time-Dependent Terms" under https://de.mathworks.com/help/matlab/ref/ode45.html shows you how ...

9 years ago | 2

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Answered
Usage of 'dsolve' function in MATLAB
"dsolve" can be used for ordinary differential equations (1 independent variable). Your equation is a partial differential eq...

9 years ago | 0

Answered
Optimize for multiple variables in nonlinear function
min: sum_{i=1}^{t_final} Power_inserted(i)*Price(i) s.t. L(t_final)-1=0 Unknowns are Power_inserted(i) (i=1,......

9 years ago | 0

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How do I constrain a vector's value within a nonlinear fit?
Put them in the fittype equation as parameters-squared. Best wishes Torsten.

9 years ago | 0

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Answered
Solving system of n linear equations with (n+1) unknowns, one unknown is constant for every equation
Try "lsqlin". If a solution with the above properties exists, you will get it with this solver. You may get m and x(i) as ...

9 years ago | 0

Answered
Nonlinear least-squares fitting of curve described by PDEs
Although the description here is for ODEs, it can easily be adopted for PDEs: https://de.mathworks.com/matlabcentral/answers/...

9 years ago | 0

Answered
How can i integrate numerically by mantaining some parameters (need to differentiate later)
Manually differentiate "fun" with respect to d. If the result is "dfun(x,d)", then D = @(d) integral(@(x)dfun(x,d),0,pi,...

9 years ago | 0

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Answered
How can i integrate numerically by mantaining some parameters (need to differentiate later)
syms x d Rs=...; Rc=...; fun = 1/(((d+Rs+Rc)^2*sin(x)^2-Rs^2)^2); I=int(fun,x,0,pi); D=diff(I,d); Best wish...

9 years ago | 0

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Double Integral with interpolateSolution() from PDE solver in MATLAB
From the documentation: _The function f must accept two arrays of the same size and return an array of corresponding values. ...

9 years ago | 0

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How to find a matrix of solutions for linear system
[X1 X2 X3 X4]=ndgrid(77,70.9:0.5:76.9,715:725,91:0.2:93]; B=[X1(:) X2(:) X3(:) X4(:)].'; A=[42.4 83 100.1 100;46.4 77.2 ...

9 years ago | 0

Answered
Solve is not returnig solution - matlab
function main x0=ones(5,1); sol=fsolve(@myfun,x0) function F=myfun(x) A=[99.23;100.05;91;107.71;104.1]; B=[...

9 years ago | 1

Answered
Error using PDEPE Function (Column Vector Mismatch)
Check the size of c,f and s: https://de.mathworks.com/help/matlab/ref/size.html If they don't have dimension (2x1) each, s...

9 years ago | 0

Answered
Solving system of differential equations (28 equations, 75 constants, and 28 initial conditions)
It's very unlikely that an analytical solution exists for a system of 28 differential equations. So use a numerical solver, e...

9 years ago | 1

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Answered
Error using * Inner matrix dimensions must agree.
f(x) with a scalar argument x returns a vector of length 6. For two vectors of length 6, the product f(xm)*f(xu) is not defin...

9 years ago | 1

Answered
double integral with singular point (not detected by integral2)
With pencil and paper, I get a value of 4*ln((sqrt(2)+1)/(sqrt(2)-1)) for your integral. The singularity at (x,y)=(...

9 years ago | 0

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Answered
Smooth Function not working
Type "ver" to see whether you have a licence for the *Curve Fitting Toolbox*. Best wishes Torsten.

9 years ago | 0

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How can I solve the following steady state Nernst Planck Poisson system by pdepe.m program?
Since your problem is stationary, use "bvp4c" instead of "pdepe". Best wishes Torsten.

9 years ago | 0

Answered
How do I truncate a normally distributed random variable?
xtl = 2.0; % left point of trunction xtr = Inf; % right point of truncation x = -4:0.1:4; y = normpdf(x); yt = no...

9 years ago | 1

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Answered
Curve fitting → z = A*exp(Tb/x)*(Cg/(Cg-y))^(C1+y*C2)
Choose the lower bound for Cg to be at least as big as the maximum value for y (i.e. 0.96). Best wishes Torsten.

9 years ago | 0

Answered
How do I truncate a normally distributed random variable?
https://de.mathworks.com/help/stats/prob.truncatabledistribution.truncate.html Best wishes Torsten.

9 years ago | 0

Answered
Error in Ode15s
Take a look at the examples -PASS EXTRA PARAMETERS TO ODE FUNCTIONS (you didn't do that correcty in your code above) and...

9 years ago | 0

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Solving a transcendental equation
n = logspace(6,13,20); V_gs = V_0+V_T*log(exp(n/g*k_B*T)-1)+V_ox; semilogy(V_gs,n) Best wishes Torsten.

9 years ago | 0

Answered
How to plot the l2 norm circle?
theta=0:2*pi/100:2*pi; x=cos(theta); y=sin(theta); plot(x,y) Best wishes Torsten.

9 years ago | 0

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Answered
how to solve the given equation using multiple values of D?
Use (1-D).^2 instead of (1-D)^2 in your definition of "eqn". And remove the line syms eqn D it's sup...

9 years ago | 0

Answered
Best curve fitting for measured data
help lsqcurvefit Best wishes Torsten.

9 years ago | 0

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