Answered

Array indices must be positive integers or logical values

Your index k starts from 0 and you are indexing h with k, so you are asking at the first iteration h(0). Matlab has 1-indexing s...

Array indices must be positive integers or logical values

Your index k starts from 0 and you are indexing h with k, so you are asking at the first iteration h(0). Matlab has 1-indexing s...

5 jours ago | 0

Answered

while loop performance improvement

I don't know the starting value of k, assuming it is 1 idx = 1:rate:period mysum = sum(array(idx,2)); % note that sum is the n...

while loop performance improvement

I don't know the starting value of k, assuming it is 1 idx = 1:rate:period mysum = sum(array(idx,2)); % note that sum is the n...

5 jours ago | 1

| accepted

Answered

Euler method error in code Index exceeds the number of array elements (1). in my my code

Checking the sintax of the code only I see 3 issues 1) In the for loop you wrote a(400-x(n)), that is you are addressing the po...

Euler method error in code Index exceeds the number of array elements (1). in my my code

Checking the sintax of the code only I see 3 issues 1) In the for loop you wrote a(400-x(n)), that is you are addressing the po...

5 jours ago | 1

| accepted

Answered

Population growth in 7 years

% rate r = 0.0063; % years t = 7; % initial population a = 5e6; % population y = a*(1+r)^t

Population growth in 7 years

% rate r = 0.0063; % years t = 7; % initial population a = 5e6; % population y = a*(1+r)^t

7 jours ago | 2

| accepted

Answered

Apply operation to each element of an array

You should use element-wise operations https://it.mathworks.com/help/matlab/matlab_prog/array-vs-matrix-operations.html In you...

Apply operation to each element of an array

You should use element-wise operations https://it.mathworks.com/help/matlab/matlab_prog/array-vs-matrix-operations.html In you...

7 jours ago | 0

| accepted

Answered

How do you solve for a double sum

There are some things that are vgue, like the x-axis, in any case, this code shows something similar to the desired result clea...

How do you solve for a double sum

There are some things that are vgue, like the x-axis, in any case, this code shows something similar to the desired result clea...

9 jours ago | 1

| accepted

Answered

Solving System of Equations

It seems you are solving a numeric system of equations. Why don't you simply put the coefficient matrix in A and the right-hand-...

Solving System of Equations

It seems you are solving a numeric system of equations. Why don't you simply put the coefficient matrix in A and the right-hand-...

11 jours ago | 0

Answered

Finding values within a matrix

It is difficult to answer because we don't have the data files 'areatemp1' and 'machtemp1'. In any case in your if statement yo...

Finding values within a matrix

It is difficult to answer because we don't have the data files 'areatemp1' and 'machtemp1'. In any case in your if statement yo...

11 jours ago | 0

Answered

Making a 3D Matrix and Adding Matrices to make a bigger matrix

In the loop, you wrote T(i+k-1,j+k-1) = d(i,j,k-1); k starts from one, so you are trying to access the d(i,j,0) elemen...

Making a 3D Matrix and Adding Matrices to make a bigger matrix

In the loop, you wrote T(i+k-1,j+k-1) = d(i,j,k-1); k starts from one, so you are trying to access the d(i,j,0) elemen...

12 jours ago | 0

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

12 jours 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;

13 jours 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 ...

13 jours 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...

13 jours 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...

14 jours 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...

14 jours ago | 0

| accepted

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 ...

15 jours 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 = (...

16 jours 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;

16 jours 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...

18 jours 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))

21 jours 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

21 jours 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...

22 jours 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...

23 jours 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 = ...

24 jours 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...

24 jours 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...

24 jours 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 ...

24 jours 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 ...

24 jours 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...

24 jours ago | 0