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Stephan


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1.423 total contributions since 2017

Knowledge means knowing where it is written...

Interested in:
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- Mathematical Modelling
- Improvement of my programming skills

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Answered
step respone, impulse response
s=tf('s'); kb=52; k1=156; k2=53; G1=10/(s+0.01); G2=G1/(1+kb*G1); G3=G2*k2*k1; G4=G3/(G3+1); subplot(2,1,1) impulse(G...

ongeveer 3 uur ago | 0

Answered
How can I do such a "countifs"(excel) process in Matlab?
You do it by logical indexing: A = randi(10,1,15) CountIf = numel(A(A>5)) gives: A = 9 7 4 10 1 5...

ongeveer 3 uur ago | 0

Answered
Dijkstra's Algorithm
You could make life easier using Matlab inbuilt graphs functions. One example is <https://de.mathworks.com/help/matlab/ref/graph...

ongeveer 17 uur ago | 1

Answered
How to find the sum of duration if the consecutive row elements are the same?
Save the durations you calculated using *|diff|* in an additional column so that the durations are correct for every row in your...

ongeveer 18 uur ago | 0

Answered
How can i sum up 56-year daily precipitation data from APHRODITE (netcdf file) into monthly?
If you organize your data in a timetable you can use retime to sum up monthly.

ongeveer 22 uur ago | 0

Answered
Generate new column from cumulating another
A = (1:4)' A(:,2) = cumsum(A) gives: A = 1 2 3 4 A = 1 1 2 3 3 ...

ongeveer 23 uur ago | 1

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Answered
mathematical expression from string input
https://de.mathworks.com/help/symbolic/str2sym.html >> fun = str2sym("(sin(sqrt(x)+a) * e^sqrt(x)) / sqrt(x)") fun = (e^...

1 dag ago | 1

Answered
Solve formal equation and get the solution with these variables
syms i1 i2 ib v1 v2 hie hre hfe hoe hfb eqns(1) = i1==-ib-hfe*ib+(v1-v2)*hoe; eqns(2) = i2==hfe*ib+(v2-v1)*hoe %ib==-v1/hie...

1 dag ago | 0

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Answered
Importing a table with unknown number of rows
I dont think it is needed to specify this, using readtable function. I never used this option to import a .csv-file as table in ...

1 dag ago | 0

Answered
Problem with solution seemingly simple linear system of equations [0x1 sym]
rewriting the system to matrix shows that this system has no solution, due to inconsistence: d=32; %mm - Srednica tłoka p1=0.5...

2 dagen ago | 0

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Answered
Integration using trapz method
1 missing bracket and you missed to define dx: d = 30; E0=8.85e-12; c=.1; dx = 0.1; a = 0; b = 1; x = a:dx:b; N = lengt...

2 dagen ago | 0

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Answered
Meshgrid fo variables in complex equation
You might want to try fimplicit3: syms f(x,y,z) f(x, y, z)=2*x+3*y+4*z==0 fimplicit3(f) or an even more complex example: f(...

3 dagen ago | 1

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Answered
Define vector v in the code
v=[2,-3,-5,6] result = prod(v(v>0))

3 dagen ago | 0

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Answered
How to split an cell array of two numbers into two columns
YouWant = [m5{:}]'

3 dagen ago | 0

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Answered
How to calculate matrix M*T=T
syms T2 T3 M = [1., 0, 0, 0;... 0.5, 0, 0.5, 0;... 0, 0.5, 0, 0.5;... 0 0 0 1.] T = [500; T2; T3; 300] B =...

3 dagen ago | 0

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Answered
how would i change an undirected network into a directed network on matlab?
here is a small example: A = [0 0 1; 0 0 1; 1 1 0] ug = graph(A) B = zeros(size(A,1)) B = B + triu(A) dg = digraph(B) ...

12 dagen ago | 1

Answered
Simplify a symbolic expression
syms s T=21.0325 L=3.5890 X=(0.6*T)*((s+(1/L))^2)/s vpa(expand(X),10)

12 dagen ago | 0

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Answered
which optimization method should I use?
Following your statements surrogateopt appears to be the correct choice.

27 dagen ago | 0

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Answered
Invalid array indexing. column 19.help
epsilon(i)(xi2(i)((1-epsilon(i)) is not allowed in Matlab, do you mean?: epsilon(i)*(xi2(i)*((1-epsilon(i))

27 dagen ago | 1

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Answered
Matlab Code (Reinforcement Learning in Finance by Alex Roumi, MathWorks)
The code has never been published. Usually the code used in webinars is published at file exchange, but this was a presentation ...

28 dagen ago | 0

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Answered
Error using horzcat:: Dimensions of array being concentenated are not consistent
There are 2 times the same values at different indices. To get only the first occourence: S=[.2046e17 .1381e17 .9249e17;.1679e1...

28 dagen ago | 0

Answered
How do i create a "Cut" at origin?
A = 5; M = 0.8; w = 1.2; fi = 30; t2 = 20; firad = fi*pi/180; t = linspace(0,t2,1000); y = M + A*sin(w.*t + firad); ...

28 dagen ago | 0

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Answered
Creating matrix with diag command
This is how a normal Matlab user would so this z = diag(1:10) z = 1 0 0 0 0 0 0 0 0 ...

28 dagen ago | 0

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Answered
not enough input data
Note that i used the same function for step2 like step1 to make it work - replace step2 with the correct function. Also i assume...

28 dagen ago | 0

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Answered
function 'step'.
step(ss(A,B,C,D))

28 dagen ago | 0

Answered
Getting lowest postive number in array with it's index
S=[-6.3e7 -0.0001e7 inf;5.2545 -.2996e7 inf] m_idx = [min(S(S>0)), find(S==min(S(S>0)))]

28 dagen ago | 0

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Answered
Changing values in atable
% Example table with random data T = splitvars(table(randi(10,10,5))) T = 10×5 table Var1_1 Var1_2 Var1_3 ...

29 dagen ago | 0

Answered
Is it possible to change the number of hidden layer in nprtool?
It is - indirectly - use patternet and then use a vector as input: net = patternnet(10); view(net) or if you need more hidden...

29 dagen ago | 0

Answered
ODE 45 step size changes the turning point
This is not a problem of Matlab, but to the misunderstanding how ode solvers in Matlab work. Read here: https://de.mathworks.co...

ongeveer een maand ago | 0

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Answered
Check for missing argument or incorrect argument data type in call to function 'log'.
Für mich funktioniert es, wenn ich numerische Werte für die Variablen definiere: TP = 500; RP = 200; PP = 201; EPS = 100; A...

ongeveer een maand ago | 0

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