Answered

Computational Electromagnetics and MATLAB

This could be a good start https://it.mathworks.com/academia/books/computational-electromagnetics-with-matlab-sadiku.html

Computational Electromagnetics and MATLAB

This could be a good start https://it.mathworks.com/academia/books/computational-electromagnetics-with-matlab-sadiku.html

2 months ago | 1

| accepted

Answered

Why am i getting the : errir using inv ,Matrix must be square?

As James Tursa said, inv(H) is not defined when H is not square. If you have the matrix H and the rhs g, simply use f = H\g;

Why am i getting the : errir using inv ,Matrix must be square?

As James Tursa said, inv(H) is not defined when H is not square. If you have the matrix H and the rhs g, simply use f = H\g;

2 months ago | 0

Answered

Struggling to Vectorize the following Code.

Almost all execution time is due to the plot function as highlighted by the profiler: You can call the plot only once at the ...

Struggling to Vectorize the following Code.

Almost all execution time is due to the plot function as highlighted by the profiler: You can call the plot only once at the ...

2 months ago | 0

Answered

How can I pick certain element from each row of an array ?

I see that the edges shared by two triangles are not duplicated. To check for this case I sorted the nodes and the edges. Let me...

How can I pick certain element from each row of an array ?

I see that the edges shared by two triangles are not duplicated. To check for this case I sorted the nodes and the edges. Let me...

2 months ago | 0

| accepted

Answered

Combining my newton's method function for nonlinear equations and my lu decomposition function.

Is this what you are asking for? delta = LUgauss(J(x0),-F_value); Note that the buil-in lu Matlab function can do the work for...

Combining my newton's method function for nonlinear equations and my lu decomposition function.

Is this what you are asking for? delta = LUgauss(J(x0),-F_value); Note that the buil-in lu Matlab function can do the work for...

3 months ago | 0

Answered

How to sum over rows within specific ranges without for loop?

Not sure if it is the best way, but this seems to work index = [0; cumsum(B)]; C = cell2mat(arrayfun(@(i)sum(A(index(i)+1:in...

How to sum over rows within specific ranges without for loop?

Not sure if it is the best way, but this seems to work index = [0; cumsum(B)]; C = cell2mat(arrayfun(@(i)sum(A(index(i)+1:in...

3 months ago | 0

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Answered

Removing Outbound (out of range) data from an array

% dimension N = 1000000; % data in (0,1) x = rand(N,1); % threshold xMin = 0.25; xMax = 0.75; % remove data out of ...

Removing Outbound (out of range) data from an array

% dimension N = 1000000; % data in (0,1) x = rand(N,1); % threshold xMin = 0.25; xMax = 0.75; % remove data out of ...

3 months ago | 0

| accepted

Answered

How to select specific values and corresponding cell positions from 31 x 12 matrix?

Because the number of rows in B is not fixed, you can store the result of your check in a cell array % create the matrix A = (...

How to select specific values and corresponding cell positions from 31 x 12 matrix?

Because the number of rows in B is not fixed, you can store the result of your check in a cell array % create the matrix A = (...

3 months ago | 0

Answered

I have a problem with integration "Error using / Matrix dimensions must agree"

When you define your functions use ./ instead of / %function f=(x+(1./x)).^2; %real value of integral ff=@(x)(x+(1./x)).^2;

I have a problem with integration "Error using / Matrix dimensions must agree"

When you define your functions use ./ instead of / %function f=(x+(1./x)).^2; %real value of integral ff=@(x)(x+(1./x)).^2;

3 months ago | 1

| accepted

Answered

Cause of: "Error: Inputs must be floats, namely single or double."

What I can see is 1) Fs is missing. In any case, tspan shpuld be a 2 entries array with initial and final values tspan = [0,15...

Cause of: "Error: Inputs must be floats, namely single or double."

What I can see is 1) Fs is missing. In any case, tspan shpuld be a 2 entries array with initial and final values tspan = [0,15...

3 months ago | 1

Answered

how to convert cell to matrix ?

A = cell2mat(cellfun(@str2num,x,'UniformOutput',false))

how to convert cell to matrix ?

A = cell2mat(cellfun(@str2num,x,'UniformOutput',false))

3 months ago | 1

Answered

Possible to modify only one portion of an array in one line?

x(x > xMax & 1:length(x) > transition) = xMax

Possible to modify only one portion of an array in one line?

x(x > xMax & 1:length(x) > transition) = xMax

3 months ago | 2

| accepted

Answered

How to compare the closest value in the matrix?

% your data unknownM = [0.8105 1.1581 0.6295 0.9594 0.8447 0.7103 0.8429 0.5372 0.9882 0.8924]; sud...

How to compare the closest value in the matrix?

% your data unknownM = [0.8105 1.1581 0.6295 0.9594 0.8447 0.7103 0.8429 0.5372 0.9882 0.8924]; sud...

3 months ago | 0

Answered

how can I create a 4D matrix and use it for interpolation

% your vectors Wpig=0.5:0.5:7; Chla=0.5:0.01:0.6; Starch=0:0.04:0.24; Now you need to sample uniformly the space using your...

how can I create a 4D matrix and use it for interpolation

% your vectors Wpig=0.5:0.5:7; Chla=0.5:0.01:0.6; Starch=0:0.04:0.24; Now you need to sample uniformly the space using your...

3 months ago | 0

Answered

How can i break down the values of vector into group of five?

If x is your vector you can reshape it y = reshape(x,5,numel(x)/5); and access each column with indexing % column 10 iCol = ...

How can i break down the values of vector into group of five?

If x is your vector you can reshape it y = reshape(x,5,numel(x)/5); and access each column with indexing % column 10 iCol = ...

3 months ago | 0

Answered

index in position 2 exceeds array bounds ( must not exceed 1).

Difficult to say without file, code, etc. The wizard says that the new excel file has only one column, but the code expects tw...

index in position 2 exceeds array bounds ( must not exceed 1).

Difficult to say without file, code, etc. The wizard says that the new excel file has only one column, but the code expects tw...

3 months ago | 0

Answered

if statement in for loop with cell arrays

To stick with the OP snippet I added semicolons all over the place I changed the variable type in s.score to doubles I preall...

if statement in for loop with cell arrays

To stick with the OP snippet I added semicolons all over the place I changed the variable type in s.score to doubles I preall...

3 months ago | 0

Answered

How to create an array and fill it by these values using loop ?

% intialization and preallocation k = 1; date = strings(480,1); % string array for i = 1982:2015 for j = 1:12 ...

How to create an array and fill it by these values using loop ?

% intialization and preallocation k = 1; date = strings(480,1); % string array for i = 1982:2015 for j = 1:12 ...

3 months ago | 0

| accepted

Answered

Monte Carlo integration of sin(x)

This code evaluates the integral using the Monte Carlo method with increasing number of random samples, compare the result with ...

Monte Carlo integration of sin(x)

This code evaluates the integral using the Monte Carlo method with increasing number of random samples, compare the result with ...

3 months ago | 0

Answered

Check if a number is in between two values

% your data a = [1,2,3,4,5,6]' b = [10,11,12,13,14,15]' Interval = [a b]; % number to check x = 8; % this finds the in...

Check if a number is in between two values

% your data a = [1,2,3,4,5,6]' b = [10,11,12,13,14,15]' Interval = [a b]; % number to check x = 8; % this finds the in...

3 months ago | 0

Answered

Assembling Element Matrices in Finite Element Method Problem

If I have understood correctly, you want to store the local 3x3 matrix in the global matrix. To do so you can (I would say must)...

Assembling Element Matrices in Finite Element Method Problem

If I have understood correctly, you want to store the local 3x3 matrix in the global matrix. To do so you can (I would say must)...

3 months ago | 1

Answered

How to find corresponding row positions of specific values in a matrix?

The function min will do this for you [B,C] = min(A,[],1);

How to find corresponding row positions of specific values in a matrix?

The function min will do this for you [B,C] = min(A,[],1);

3 months ago | 0

| accepted

Answered

How to convert script from fortran90 to matlab language

Again, it is difficult to check if not all code is available, however I try kB = zeros(10,1); kA = zeros(10,1); kL = 0; kS =...

How to convert script from fortran90 to matlab language

Again, it is difficult to check if not all code is available, however I try kB = zeros(10,1); kA = zeros(10,1); kL = 0; kS =...

3 months ago | 1

| accepted

Answered

Pad with Nan according to maximum row in cell

I keep all steps separated % the data A = {rand(47,1),rand(80,1),rand(97,1)}; % pad with NaNs A = cellfun(@(x)[x(1:end); N...

Pad with Nan according to maximum row in cell

I keep all steps separated % the data A = {rand(47,1),rand(80,1),rand(97,1)}; % pad with NaNs A = cellfun(@(x)[x(1:end); N...

3 months ago | 0

| accepted

Answered

Keeping Previous Iteration changes

I see two problems in your code 1) the changes are only temporarily saved in x and x is never used 2) onec you change a letter...

Keeping Previous Iteration changes

I see two problems in your code 1) the changes are only temporarily saved in x and x is never used 2) onec you change a letter...

3 months ago | 0

Answered

How to get rid of Nan when calculating mean

Following Steven Lord answer I would usE mean(A(isfinite(A)))

How to get rid of Nan when calculating mean

Following Steven Lord answer I would usE mean(A(isfinite(A)))

3 months ago | 0

Answered

Why is my script not working?

I try 1) I think you are caluclating the jacobian matrix. To avoid mistakes I did this symbolically and the result is >> syms...

Why is my script not working?

I try 1) I think you are caluclating the jacobian matrix. To avoid mistakes I did this symbolically and the result is >> syms...

3 months ago | 0

| accepted

Answered

Extract values from image

I assume you have X,Y and B as created using meshgrid, and the line is specified by start/end node % create dummy data x = lin...

Extract values from image

I assume you have X,Y and B as created using meshgrid, and the line is specified by start/end node % create dummy data x = lin...

3 months ago | 0

| accepted

Answered

Help with nested for loop generating coordinates

The command you are looking for is meshgrid % vectors with positions x = 0.00470:.0003:.0071; y = 0.00470; z = 0:0.00005:.00...

Help with nested for loop generating coordinates

The command you are looking for is meshgrid % vectors with positions x = 0.00470:.0003:.0071; y = 0.00470; z = 0:0.00005:.00...

3 months ago | 0