Community Profile # Torsten

Last seen: ein Tag ago Active since 2013

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Solve system of equations with two unknowns (should be the smallest rational number possible)
Easy for a,b real: a = b = sqrt(k). More involved for a,b rational. For a,b real it can be solved as an optimization if you d...

etwa 13 Stunden ago | 0

How to calculate the intersection point of lines on a loglog graph.
eprime=0.59; sigmaprime=277500; %Constants for Manson Coffin Equation b=-0.087; c=-0.58; %Young's Modulus E=30*10^6; ...

etwa 14 Stunden ago | 1

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i need to get my variable y to vary....as its a key variable for this entire system. i cant seem to find a way. would you help me in that regard...
In x0, set y to the value you want. In PBR, set dxdW = [dnNO_dW; dnH2_dW; dnN2_dW; dnH2O_dW; dnN2O_dW; dnO2_dW; 0.0; dT_dW]; ...

etwa 16 Stunden ago | 0

Calculate the area and volume of revolution based on some data points
y = [0,38.161563,39.751307,40.878082,42.701189,44.524296,45.047229,45.990198,46.933167,46.785121,... 46.225562,41.318857,36...

etwa 18 Stunden ago | 2

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How to use "poissrnd" function?
lambda = 4 What is the unit of lambda ? Mean number of arrivals per minute ? And you want to get a random vector for arrivals...

etwa 19 Stunden ago | 0

Store prime and non-prime numbers
x=[1:50]; x=x'; jj=0; %index for prime_num nn=1; %index for nonprime_num p=[]; np=[]; np(1) = 1; for i=2:length(x) i...

etwa 21 Stunden ago | 1

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Can someone explain to me how to code the Tangent line and Normal line

etwa 22 Stunden ago | 0

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Extract values from one matrix and with iteration solve the system of linear equations
B = rand(3,3); A1 = 4; rhs = -A1*B(1,:).'; Mat = [-ones(3,1),B(2:3,:).']; sol = Mat\rhs; C1 = sol(1) A2 = sol(2) A3 = s...

etwa 23 Stunden ago | 0

I get "vectors must be the same length". How come?
How do you want to plot a vector of length 302 against a vector of length 352 ? It's not possible. x1 = 0:0.1:5; x2 = 5:0.1:35...

etwa 23 Stunden ago | 0

Is there any way to find the row with closest values in matrix with a given array values?
How do you define "closest" ? The Euclidean distance between array and rows of the matrix ? Then you can use mat1 = [1.0000 ...

etwa 23 Stunden ago | 0

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linear combination of vector and permutation
values = [-1 1]; %// data k = 3; %// data n = numel(values);...

ein Tag ago | 1

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a simple calculation by each row
Take ^(1/eta) of both sides of the equations. You get linear equations in x. Solve them. See solution above.

ein Tag ago | 1

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Does MATLAB have inverse tangent integral TI2(z)?
format long x = 0.5; Ti2 = 1i*( -dilog(1-1i*x) + 0.25*dilog(1+x.^2) ) Ti2_compare = integral(@(x)atan(x)./x,0,x)

ein Tag ago | 0

matlab not using the variable i give it in differential equation
syms k N t P(t) knum = 0.025; Nnum = 1000; sol = simplify(dsolve(diff(P,t)==k*P*(1-(P/N)), P(0)==200)) sol = subs(sol,[k N],...

ein Tag ago | 0

Failure in initial objective function evaluation. FSOLVE cannot continue.
fun = @root7d; x0 = [10,10]; x = fsolve(fun,x0) fun(x) function F = root7d(x) %parameters vp=100; kp=0.5; q=1;...

ein Tag ago | 0

problem using the solve method
syms t eqn = 1000/(exp(log(4) - t/40) + 1) == 800; tsol = vpa(solve(eqn, t))

ein Tag ago | 0

How can I fix "Error in sym/subsref (line 898) R_tilde = builtin('subsref',L_tilde,Idx); ?
KgQ(indiciesQ,indiciesQ) = KgQ(indiciesQ,indiciesQ) + subs(KeQ,[x1Q x2Q x3Q], [xQ(i*2-1) xQ(i*2) xQ(i*2+1)]); % Ke into Kg contr...

2 Tage ago | 0

Solving 3 equations with 3 unknowns
No problem. A = [2*sqrt(44.4) 0 0; 2*sqrt(34) 2*sqrt(3.92) 2*sqrt(57.4);2*sqrt(21.8) 2*sqrt(25.5) 2*sqrt(25.5)]; b = [52.11;52...

2 Tage ago | 1

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If I had the derivative of an equation and had data points how would I plot them
d = @(x)1 - sin(x)./(2*sqrt(x)) - sqrt(x).*cos(x); x = [1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0]; plot(x,d(x))

3 Tage ago | 0

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All combinations of the sum of 2 columns
a = [29;31;34].' ; b = [31;31;31] ; x = b-a xmax = max(x(:))

3 Tage ago | 1

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secant method exceeds the number of array
x(i+2)=x(i)-(fun(x(i))*((x(i+1)-x(i))/(fun(x(i+1))-fun(x(i))))); For i = 1, the evaluation of the right-hand side needs x(1) an...

3 Tage ago | 0

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How to create a Fourier series using for loops
k = 1:14; x = (-2:0.01:2).'; f = 0.5 + sum(2./(k.^2*pi^2).*((-1).^k-1).*cos(pi*k.*x/2) + 2./(k*pi).*(-1).^(k+1).*sin(pi*k.*x/2...

3 Tage ago | 0

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Problem solving exponential equation
Your parantheses are unbalanced. After correcting it, the below code should work. syms t eqn = 1000/(exp(log(4) - t/40) + 1 ==...

3 Tage ago | 0

How to quickly identify a list of nearby stations?
https://de.mathworks.com/help/stats/pdist.html And for your double loop, you should replace for i=1:m2 for j=1:m2 by fo...

3 Tage ago | 0

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need a for loop that displays value at each point of x.
But I already gave you the formulae how to code "cumtrapz": 0 = ctrapz(1) [f(x0)+f(x1)]/2 * (x1-x0) = ctrapz(2) [f(x0)+f(x1)]...

3 Tage ago | 0

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Putting togethor constraints for fmincon
The conditions defined under "ineqconstraint" have to be put into the matrix A and the vector b of "fmincon".

3 Tage ago | 0

'corrcoef' doesn't return a matrix as it should, but I always get 1?
for i=1:numel(time) coefR{i} = corrcoef((res2(i,:)).',(res3(i,:)).'); end

3 Tage ago | 0

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plotting functions from book
c = 1; k = 1.2:0.4:2.8; u = (linspace(0,2.4,100)).'; f = (k/c).*(u/c).^(k-1).*exp(-(u/c).^(k)); plot(u,f)

3 Tage ago | 0

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