801 total contributions since 2017

Knowledge means knowing where it is written...

Interested in:

- Optimization

- Mathematical Modelling

- Improvement of my programming skills

Answered

Write to text file

Hi, note the permission argument for fopen. The way you call the files is read only permission. Best regards Stephan

Write to text file

Hi, note the permission argument for fopen. The way you call the files is read only permission. Best regards Stephan

5 days ago | 1

Answered

Hello, any one help me, what is this question's solution?

doc polyfit doc roots

Hello, any one help me, what is this question's solution?

doc polyfit doc roots

5 days ago | 0

Answered

how can I solve this question? I need help

Have a read here: https://de.mathworks.com/help/matlab/ref/polyfit.html Best regards Stephan

how can I solve this question? I need help

Have a read here: https://de.mathworks.com/help/matlab/ref/polyfit.html Best regards Stephan

6 days ago | 1

Answered

Error using fminunc function

Hi, you have a script that is named roots.m - roots is an inbuilt function. This causes problems. Rename your script to solve...

Error using fminunc function

Hi, you have a script that is named roots.m - roots is an inbuilt function. This causes problems. Rename your script to solve...

7 days ago | 1

| accepted

Answered

piloting log in y cordinate

Hi, try: format shortG kxx = 2.0e4; kyy = 8.8e4; kxy = 1.0e3; kyx = 1.5e3; cxx = 1.0 ; cyy = 1.0; cxy = 1.0e-1; cyx = 1....

piloting log in y cordinate

Hi, try: format shortG kxx = 2.0e4; kyy = 8.8e4; kxy = 1.0e3; kyx = 1.5e3; cxx = 1.0 ; cyy = 1.0; cxy = 1.0e-1; cyx = 1....

10 days ago | 0

| accepted

Answered

How do I use ga correctly? fitness function

Hi, the line where ga is called [d endPop trace]=ga([],bounds(:,1),bounds(:,2),linOptFcn,IdentParams,[70 -1],'maxGenTerm',opt...

How do I use ga correctly? fitness function

Hi, the line where ga is called [d endPop trace]=ga([],bounds(:,1),bounds(:,2),linOptFcn,IdentParams,[70 -1],'maxGenTerm',opt...

10 days ago | 0

Answered

help how can I use the PSO algorithme for the case of a matrix ?!

Hi, you can use the reshape function and take advantage of the linear indexing in Matlab. This will allow to work with matrices...

help how can I use the PSO algorithme for the case of a matrix ?!

Hi, you can use the reshape function and take advantage of the linear indexing in Matlab. This will allow to work with matrices...

10 days ago | 0

Answered

Why the seond arugment in the command jacobian is not a vector of variables?

Hi, you declare b1...b3 as symbolic functions of t - not as symbolic variables. Thats why it doesnt work. Here is an example: ...

Why the seond arugment in the command jacobian is not a vector of variables?

Hi, you declare b1...b3 as symbolic functions of t - not as symbolic variables. Thats why it doesnt work. Here is an example: ...

10 days ago | 0

| accepted

Answered

Vibration Analysis of a gas turbine

Hi, there are some example in the documentation regarding Vibration analysis: <https://de.mathworks.com/help/signal/exampl...

Vibration Analysis of a gas turbine

Hi, there are some example in the documentation regarding Vibration analysis: <https://de.mathworks.com/help/signal/exampl...

11 days ago | 0

Answered

How to find a polynomial of degree 2 that fits the given data with minimal approximation error? and then sketch discrete points and the graph of the polynomial

Hi, <https://de.mathworks.com/help/matlab/ref/polyfit.html polyfit> does the job: [p,S,mu] = polyfit(x,y,n) in your c...

How to find a polynomial of degree 2 that fits the given data with minimal approximation error? and then sketch discrete points and the graph of the polynomial

Hi, <https://de.mathworks.com/help/matlab/ref/polyfit.html polyfit> does the job: [p,S,mu] = polyfit(x,y,n) in your c...

12 days ago | 0

Answered

Failure in initial user-supplied objective function evaluation. FSOLVE cannot continue

Hi, this runs - not sure if it is really efficient, but it works: x0=[1,1,1,1,1]; fsolve(@F,x0) function m=F(x) syms y1 ...

Failure in initial user-supplied objective function evaluation. FSOLVE cannot continue

Hi, this runs - not sure if it is really efficient, but it works: x0=[1,1,1,1,1]; fsolve(@F,x0) function m=F(x) syms y1 ...

12 days ago | 0

| accepted

Answered

help in solving an error

Hi, try: % Solving the 2-D Poisson equation by the Finite Difference ...Method % Numerical scheme used is a second order ce...

help in solving an error

Hi, try: % Solving the 2-D Poisson equation by the Finite Difference ...Method % Numerical scheme used is a second order ce...

13 days ago | 0

| accepted

Answered

SOLVING LARGE SYSTEM OF EQUATIONS

Hi, try: a = sym('a',[1 15]); syms r p1 = poly2sym(a,r); diff = sym('diff'); eq = sym('eq'); fprintf('\n polynomial: %s\n...

SOLVING LARGE SYSTEM OF EQUATIONS

Hi, try: a = sym('a',[1 15]); syms r p1 = poly2sym(a,r); diff = sym('diff'); eq = sym('eq'); fprintf('\n polynomial: %s\n...

14 days ago | 0

| accepted

Answered

where i can find video tutorials for GFDM for free?

You might be interested in this: <https://www.mathworks.com/videos/5gltewlan-waveform-generation-simulation-measurement-and-ov...

where i can find video tutorials for GFDM for free?

You might be interested in this: <https://www.mathworks.com/videos/5gltewlan-waveform-generation-simulation-measurement-and-ov...

14 days ago | 0

Answered

Is there a way to combine number of matrices into one?

Hi, this solution is evil - since it uses eval: A = whos; A = {A.name}; B = string(ones(1,2*numel(A)-1)); B(2:2:end) = ","...

Is there a way to combine number of matrices into one?

Hi, this solution is evil - since it uses eval: A = whos; A = {A.name}; B = string(ones(1,2*numel(A)-1)); B(2:2:end) = ","...

15 days ago | 0

Answered

Why is plot(x,y=0) not giving a line at y=0?

Hi, no need for this - since you are using R2018b you can take advantage of the yline function: x=0:0.01:10*pi; plot(x,2*sin(...

Why is plot(x,y=0) not giving a line at y=0?

Hi, no need for this - since you are using R2018b you can take advantage of the yline function: x=0:0.01:10*pi; plot(x,2*sin(...

15 days ago | 2

Answered

How do i find the intersection between two curves?

Hi, usually this can be aproximated with quadratic functions - so you can use polyfit and polyval to calculate functionsthe de...

How do i find the intersection between two curves?

Hi, usually this can be aproximated with quadratic functions - so you can use polyfit and polyval to calculate functionsthe de...

17 days ago | 1

Answered

How to plot the function y=sin(t)/t for -4*pi<x<4*pi?

Hi, at least two ways possible: Symbolic: syms t fplot(sin(t)/t,[-4*pi, 4*pi]) Numeric: t = linspace(-4*pi,4*pi); y = sin...

How to plot the function y=sin(t)/t for -4*pi<x<4*pi?

Hi, at least two ways possible: Symbolic: syms t fplot(sin(t)/t,[-4*pi, 4*pi]) Numeric: t = linspace(-4*pi,4*pi); y = sin...

17 days ago | 0

Answered

Daily Return plot without interpolating lines

Hi, try: plot(returns) Best regards Stephan

Daily Return plot without interpolating lines

Hi, try: plot(returns) Best regards Stephan

17 days ago | 0

Answered

How can I store the value at each iteration of a genetic algorithm?

Hi, you coultd try this way: [x,fval,vals] = solve_problem function [x,fval,vals] = solve_problem ObjFcn = @myFitness; ...

How can I store the value at each iteration of a genetic algorithm?

Hi, you coultd try this way: [x,fval,vals] = solve_problem function [x,fval,vals] = solve_problem ObjFcn = @myFitness; ...

17 days ago | 1

| accepted

Answered

How to solve an optimization problem with stability constraints using 'fmincon'?

Hi, i would try by writing a nonlinear constraint function for fmincon, that calculates the eigenvalues for each iteration an...

How to solve an optimization problem with stability constraints using 'fmincon'?

Hi, i would try by writing a nonlinear constraint function for fmincon, that calculates the eigenvalues for each iteration an...

18 days ago | 0

Answered

Detect isolated nodes from tree graph mathematically through incidence matrix or adjacency matrix or any other mathematical method?

Hi, Matlab has his own graph functions. Learn how to define a graph object in Matlab, will help you saving a lot of time for ...

Detect isolated nodes from tree graph mathematically through incidence matrix or adjacency matrix or any other mathematical method?

Hi, Matlab has his own graph functions. Learn how to define a graph object in Matlab, will help you saving a lot of time for ...

18 days ago | 0

| accepted

Answered

plotting a series of lines with specified colours

Hi, try: clf clc clear all close all % DATA Depth= [0 2 4 6 8 12 16 20 24 28 30 32 36 40]; % P-waves vp_upt= [3.27 5....

plotting a series of lines with specified colours

Hi, try: clf clc clear all close all % DATA Depth= [0 2 4 6 8 12 16 20 24 28 30 32 36 40]; % P-waves vp_upt= [3.27 5....

18 days ago | 0

| accepted

Answered

How to find the gradient of a function in spherical coordinates system ?

Hi, take advantage of the gradient function: syms x y z A = x^2*y+x*y*z res = gradient(A,[x y z]) results in: res = 2...

How to find the gradient of a function in spherical coordinates system ?

Hi, take advantage of the gradient function: syms x y z A = x^2*y+x*y*z res = gradient(A,[x y z]) results in: res = 2...

19 days ago | 1

Answered

the simscape of mass-spring-damping system can't get the ideal result

Hi, did you notice that you can accept and/or vote for useful answers? You have a asked a bunch of questions ang got some answe...

the simscape of mass-spring-damping system can't get the ideal result

Hi, did you notice that you can accept and/or vote for useful answers? You have a asked a bunch of questions ang got some answe...

20 days ago | 0

| accepted

Answered

Reshaping 2x52 array into 1 special row

A = [1 2; 3 4; 5 6; 7 8] B = reshape(A',1,[]) gives: A = 1 2 3 4 5 6 7 8 B = ...

Reshaping 2x52 array into 1 special row

A = [1 2; 3 4; 5 6; 7 8] B = reshape(A',1,[]) gives: A = 1 2 3 4 5 6 7 8 B = ...

21 days ago | 1

Answered

How to get a function to accept a vector as input?

Hi, no if-else is needed, when using logical indexing: function [x] = classproj(W, k1, k2, d) x(W.*(1/k1)<d) = W(W.*(1/...

How to get a function to accept a vector as input?

Hi, no if-else is needed, when using logical indexing: function [x] = classproj(W, k1, k2, d) x(W.*(1/k1)<d) = W(W.*(1/...

21 days ago | 2

| accepted

Answered

data from first line to two column

A=[1.4282E-01, 5.0537E+00, 1.2573E-01, 5.0537E+00, 1.8311E-02, 5.0513E+00]; B=reshape(A,2,[])'

data from first line to two column

A=[1.4282E-01, 5.0537E+00, 1.2573E-01, 5.0537E+00, 1.8311E-02, 5.0513E+00]; B=reshape(A,2,[])'

21 days ago | 0

| accepted

Answered

difference between next two numbers

Hi, you may want to use the diff function. Best regards Stephan

difference between next two numbers

Hi, you may want to use the diff function. Best regards Stephan

21 days ago | 1