Stephan

Last seen: Today

1.423 total contributions since 2017

Knowledge means knowing where it is written...

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

Stephan's Badges

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

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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

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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

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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

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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

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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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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

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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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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

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

3 dagen ago | 0

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

3 dagen ago | 0

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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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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

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

27 dagen ago | 0

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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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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

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

28 dagen ago | 0

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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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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

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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

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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