Community Profile

# Stephan

657 total contributions since 2017

Knowledge means knowing where it is written...

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

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I can't find where the mistake is. Could anyone help me with my code?
Hi, the way you define t is not useful. Use: t = [0 100] What you do is corresponding to a sample rate of 1 second. This lets...

2 days ago | 0

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Solving simultaneous time-dependent matrix equations
Hi, try: % Defining constants A_a = 7.7790; g1_1 = [0.0019 0.0076] g2_1 = [0.0021 0.0083] ga_1 = [0.1862 0.3725] Hv1 = 2....

2 days ago | 0

how to create a time table from a table with a column with year number as row times?
Hi, try: arimaxdata.t = years(arimaxdata.t) arimaxdata = table2timetable(arimaxdata) Best regards Stephan

3 days ago | 0

Having trouble solving system of equations
Hi, shorter: syms c1 c2 [sol_c1, sol_c2] = vpasolve(c1==18*c1-1200+((4.8195*10^-8)*(((0.3*c1+c2)^4)-18^4)),c1==(20*c2-500)/-0...

3 days ago | 1

License reinstate fee should be more flexible.
Hi, this forum is run by volunteer Matlab users who can not comment on TMW's licensing policy. You should consider sending your...

4 days ago | 0

Looking for candlestick, rsi, csv file example
Hi, here is a working example for candlestick containing .csv-data which works on R2018b: https://de.mathworks.com/matlabcentr...

4 days ago | 0

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optmization problem in hybrid energy storage system.
Hi, there is an example given which appears to be similar to the task you want to do: https://de.mathworks.com/help/optim/ug/o...

4 days ago | 0

Red Dotted Wire Problem
Hi, try: https://de.mathworks.com/help/physmod/simscape/ref/voltagesensor.html coupling physical signals to usual Simulink si...

4 days ago | 0

isAlways(x^2>=0) is unable to give a solution. Why so when the problem is so simple?
Hi, Matlab also calculates with complex numbers. Make assumptions on x: syms x assume(x,'real') result = isAlways(x^2>=0) ...

4 days ago | 2

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Branch and bound optimization
Hi, see here: https://de.mathworks.com/help/optim/ug/intlinprog.html?s_tid=doc_ta#bts3f9f-4 Best regards Stephan

4 days ago | 0

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Receiving 'Dimensions of arrays being concatenated are not consistent.' error, but there are equal amounts of rows being input.
Hi, try: T = table(Mean, Std_Error, Deviation, Variance, Min, Max, Range, Confidence_95,'VariableNames',{'mean','sem','std','v...

6 days ago | 2

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Is there a way to extract the name of a field of a struct as string
Hi, the following gives a string array with the fieldnames of the struct: A.a123 = 1 A.bbb = 2 B = string(fieldnames(A)) pi...

6 days ago | 0

Lab 04 - What to do
What to do? This is easy: Read the instructions, read the documentation site of Matlab, make an effort and try it on your own. ...

9 days ago | 0

ga algorithm with vectors
Hi, check this example in the documentation: https://de.mathworks.com/help/gads/solving-a-mixed-integer-engineering-design-pro...

9 days ago | 0

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Signal Processing Feature Extraction in regards to Siren Detection
Hi, your question is nearly unanswerable. You ask very unspecific and we do not know what you already did. What kind of sirens ...

10 days ago | 0

I can not zero my transfer function
Hi, i assume you want to use zero instaed of zeros. The first is for control - the second creates an array of all zeros, which ...

10 days ago | 0

mean() is giving me an error, when when I use the test code Matlab suggests
Hi, if you work with R2018a you should use the documentation from R2018a instead of R2018b. Work through the correct documentat...

10 days ago | 1

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Multi Variable Non-linear Curve Fitting in MATLAB
Hi, i suggest to model this as a system of 4 equations with the 15 unknownse and use . 3 equations to calculate the tau(i) valu...

10 days ago | 0

how to plot the graph with the required data
Hi, as Madhan suggested you can use piecewise function. If you do not have access to Symbolic Math Toolbox (which is needed for...

10 days ago | 0

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How do I make a vector where the entries are months and years?
date = datestr(join([string(repelem(2006:2012,1,12)'),string(repmat(1:12,1,7)')],2),'mmm-yyyy')

11 days ago | 0

In need of decreasing exponential smooth curve
Your linspace call will lead to 10 results calculated in the interval of 0...1. If you leave the 10 away, the standard is 100 va...

11 days ago | 0

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Why is the reported accuracy of the Classification learner app very low (51%), while in the scatter plots, no incorrect model predictions are reported?
Hi, the red area in the confusion matrix tells us, that there were 4433 times when the predicted class was 1 and the true clas...

12 days ago | 0

Type 1 Cosine Transform
Hi, the option 'Type' was introduced in R2017a - see the release notes for Signal Processing Toolbox. To avoid this kind of is...

14 days ago | 0

How can I go about calling another function and estimating a solution?
Your new script: A = [3, 123456789, 8, 5; 2, 13,...]; b = [246913625, ...]; [x, det] = single(nvgss(A,b)) Best regards Step...

17 days ago | 0

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Solved

Equal to their cube
Tell me three real numbers that are equal to their cubes?

17 days ago

Solved

Solve the set of simultaneous linear equations
Given this pair of simultaneous linear equations: 2x + 3y = 23 3x + 4y = 32 Find the solution set (x,y)

17 days ago

Solved

Add a row of zeros on top of a matrix
Given a matrix, insert a row of zeros as the top row.

17 days ago

Solved

Area of a Square
Inside a square is a circle with radius r. What is the area of the square?

17 days ago

Solved

Find the sum of the elements in the "second" diagonal
Find the sum of the elements in the diagonal that starts at the top-right corner and ends at the bottom-left corner.

17 days ago

Solved

Remove the Zero
Given an array n, remove all zeros

17 days ago