Answered

Optimizing calculation of eigenvectors and eigenvalues

Hi Guiseppi, there is nothing guaranteed about the order of the eigenvalues that are produced by eig. And if you do the first ...

Optimizing calculation of eigenvectors and eigenvalues

Hi Guiseppi, there is nothing guaranteed about the order of the eigenvalues that are produced by eig. And if you do the first ...

etwa 2 Monate ago | 2

| accepted

Answered

Creating Polar mesh in matlab

Hi Reza, % make a rectangular grid of r and theta, % then define x and y in the usual way rr = 0:1:20; thth = (0:.05:1)*2*p...

Creating Polar mesh in matlab

Hi Reza, % make a rectangular grid of r and theta, % then define x and y in the usual way rr = 0:1:20; thth = (0:.05:1)*2*p...

etwa 2 Monate ago | 0

| accepted

Answered

Why when calculating impulse response of a filter (system) I get a “tail” at the end

Hi Yurii, It looks like the 'lowpass' function is doing something unexpected, which causes this. In order to get the transfer ...

Why when calculating impulse response of a filter (system) I get a “tail” at the end

Hi Yurii, It looks like the 'lowpass' function is doing something unexpected, which causes this. In order to get the transfer ...

etwa 2 Monate ago | 0

Answered

Peculiar Result with Solve (Symbolic Math Toolbox) with Three Equations and Three Unknowns. Can Anyone Explain?

Hi Paul, certainly in the first case, [eps/5, 4eps/5,eps] is a solution for any nonzero eps, and if you let eps--> 0 and invo...

Peculiar Result with Solve (Symbolic Math Toolbox) with Three Equations and Three Unknowns. Can Anyone Explain?

Hi Paul, certainly in the first case, [eps/5, 4eps/5,eps] is a solution for any nonzero eps, and if you let eps--> 0 and invo...

etwa 2 Monate ago | 0

Answered

Find the common eigenvectors and eigenvalues between 2 matrices

Hi petit, Eigenvectors calculated by Matlab are normalized, but neither (a) the the overall phase of each one or (b) the order ...

Find the common eigenvectors and eigenvalues between 2 matrices

Hi petit, Eigenvectors calculated by Matlab are normalized, but neither (a) the the overall phase of each one or (b) the order ...

etwa 2 Monate ago | 0

| accepted

Answered

means squared error and dB

Hi MatG, As with a lot of things, the answer depends. In your example, which is the first case below, the variation in power i...

means squared error and dB

Hi MatG, As with a lot of things, the answer depends. In your example, which is the first case below, the variation in power i...

2 Monate ago | 0

| accepted

Answered

Given One Partition of a Matrix, What is the Best Way to Find a Second Partition that Ensures the Matrix is Nonsingular?

Hi Paul, First of all, if C is not close to full rank, there can be numerical problems with most any calculation involving C. ...

Given One Partition of a Matrix, What is the Best Way to Find a Second Partition that Ensures the Matrix is Nonsingular?

Hi Paul, First of all, if C is not close to full rank, there can be numerical problems with most any calculation involving C. ...

2 Monate ago | 0

| accepted

Answered

convolution of exponential with unit step ... using conv command

Hi Muhammed, since your reply is a copy of the the orignal code, nothing changes. Anyway, the reason for the effect is that wh...

convolution of exponential with unit step ... using conv command

Hi Muhammed, since your reply is a copy of the the orignal code, nothing changes. Anyway, the reason for the effect is that wh...

2 Monate ago | 0

Answered

Please help me convert spectral integral equation to matlab code.

Hi Emma, Seeing the actual problem helped. It sounds like this is supposed to be a region-1-only problem with region 2 out of ...

Please help me convert spectral integral equation to matlab code.

Hi Emma, Seeing the actual problem helped. It sounds like this is supposed to be a region-1-only problem with region 2 out of ...

2 Monate ago | 0

Answered

Logical Indexing via multiplication

Hi Inna, not done by multiplication, but: ind = find(A==1) rows_you_want = B(ind,:) the colon means to take every column in w...

Logical Indexing via multiplication

Hi Inna, not done by multiplication, but: ind = find(A==1) rows_you_want = B(ind,:) the colon means to take every column in w...

2 Monate ago | 0

| accepted

Answered

how to check if a point is inside an rotated ellipsoid?

Hi Amin, Since it appears that you know the rotation matrix, you can rotate the point p in question in the opposite direction t...

how to check if a point is inside an rotated ellipsoid?

Hi Amin, Since it appears that you know the rotation matrix, you can rotate the point p in question in the opposite direction t...

3 Monate ago | 1

| accepted

Answered

Since the matrix is near to singular I have tried pinv to solve but getting too deviated answers. Can you please let me know if there is any other way to solve the equations

Hi VS, Usually in these cases, finding the determinant is not as useful as finding the condition number. Unless you can show t...

Since the matrix is near to singular I have tried pinv to solve but getting too deviated answers. Can you please let me know if there is any other way to solve the equations

Hi VS, Usually in these cases, finding the determinant is not as useful as finding the condition number. Unless you can show t...

3 Monate ago | 0

| accepted

Answered

How to find the delta cycles (change in the number of cycles) in two sine signals with nearly identical frequencies?

Hi Jay, Using the hilbert transform on the signal gives the so-called analytic signal. The transform creates an imaginary part...

How to find the delta cycles (change in the number of cycles) in two sine signals with nearly identical frequencies?

Hi Jay, Using the hilbert transform on the signal gives the so-called analytic signal. The transform creates an imaginary part...

3 Monate ago | 0

Answered

Guess update for Bessel function

Hi JS, For j = 1, figure 1 shows the general behavior of the function. Since it's a plot of log(abs(fun)) there can be no zero...

Guess update for Bessel function

Hi JS, For j = 1, figure 1 shows the general behavior of the function. Since it's a plot of log(abs(fun)) there can be no zero...

3 Monate ago | 0

| accepted

Answered

What kind of sorting algorithm is this?

Hello Karen, I guess it could depend on what is meant by 'corresponds to', since this sort is O(n^2) as is the bubble sort. So...

What kind of sorting algorithm is this?

Hello Karen, I guess it could depend on what is meant by 'corresponds to', since this sort is O(n^2) as is the bubble sort. So...

3 Monate ago | 1

| accepted

Answered

sum two variables ignoring NaN

Hi alpedhuez, sum(Var1,Var2,2,'omitnan') Here the '2' indicates that you are summing rows rather than columns (the default is ...

sum two variables ignoring NaN

Hi alpedhuez, sum(Var1,Var2,2,'omitnan') Here the '2' indicates that you are summing rows rather than columns (the default is ...

3 Monate ago | 0

Answered

How to make a color scale like this?

Hi pf, I copied in the image in your posting (a jpeg) and called it image1. That results in a 3d array that is 180x882x3 uint8...

How to make a color scale like this?

Hi pf, I copied in the image in your posting (a jpeg) and called it image1. That results in a 3d array that is 180x882x3 uint8...

3 Monate ago | 0

Answered

FFT of coupled oscillator from time domain (picosecond) to frequency domain (wavenumber, cm-1)

HI Kunjanni, this occurs because the fft contains both positive and negative frequency (wavenumber) components. Zero frequency...

FFT of coupled oscillator from time domain (picosecond) to frequency domain (wavenumber, cm-1)

HI Kunjanni, this occurs because the fft contains both positive and negative frequency (wavenumber) components. Zero frequency...

3 Monate ago | 0

| accepted

Answered

Exponential function produces error with integrate command

Hi Ben for large x, exp(x) overflows to infinity before the exp(-(x.^2)/2) factor has a chance to bring in down. Try completin...

Exponential function produces error with integrate command

Hi Ben for large x, exp(x) overflows to infinity before the exp(-(x.^2)/2) factor has a chance to bring in down. Try completin...

3 Monate ago | 0

| accepted

Answered

Even distribution of coordinates subset

Hi Giovanni, here is one method, which assumes that B is supposed to span basically the entire domain of A. Suppose the set of...

Even distribution of coordinates subset

Hi Giovanni, here is one method, which assumes that B is supposed to span basically the entire domain of A. Suppose the set of...

3 Monate ago | 0

| accepted

Answered

Why does pcolor require you to transpose the matrix when you give it x and y vectors?

Hi Darcy. pcolor works in the same fashion as meshgrid, and creates a grid with nx = length(x) columns and ny = length(y) rows....

Why does pcolor require you to transpose the matrix when you give it x and y vectors?

Hi Darcy. pcolor works in the same fashion as meshgrid, and creates a grid with nx = length(x) columns and ny = length(y) rows....

3 Monate ago | 0

Answered

Undefined function 'sinc' for input arguments of type 'double'.

Hi boutaina, Since it's easy in Matlab to make your own functions, you don't need toolboxes that are (probably not intentionall...

Undefined function 'sinc' for input arguments of type 'double'.

Hi boutaina, Since it's easy in Matlab to make your own functions, you don't need toolboxes that are (probably not intentionall...

3 Monate ago | 0

Answered

Choose Lyapunov function of a linear system

Hi Cristina, The first part of this is probably telling you what you already know, but denoting C = c*[1 -1 0; 0 1 -1; -1 0 1]...

Choose Lyapunov function of a linear system

Hi Cristina, The first part of this is probably telling you what you already know, but denoting C = c*[1 -1 0; 0 1 -1; -1 0 1]...

3 Monate ago | 0

Answered

orthagonal planes and normal vectors

Hi M, A plane satisfies the dot product equation equation r dot v = const where r is the position vector [x y z] and v = [vx ...

orthagonal planes and normal vectors

Hi M, A plane satisfies the dot product equation equation r dot v = const where r is the position vector [x y z] and v = [vx ...

3 Monate ago | 2

| accepted

Answered

How to generate a random complex unitary matrix whose columns each sum up to 1

MODIFIED to replace previous random function Hi Michael, here is one way. It's based on the idea that if the unitary matrix U...

How to generate a random complex unitary matrix whose columns each sum up to 1

MODIFIED to replace previous random function Hi Michael, here is one way. It's based on the idea that if the unitary matrix U...

3 Monate ago | 1

| accepted

Answered

Solving a 3 degree of freedom mass spring damper model

Hi Z^2, Now that you have the K, C and M matrices, you can create a matrix equation to find the natural resonant frequencies. G...

Solving a 3 degree of freedom mass spring damper model

Hi Z^2, Now that you have the K, C and M matrices, you can create a matrix equation to find the natural resonant frequencies. G...

3 Monate ago | 0

Answered

Solve for the constants of a Quartic given the complex roots?

Hi Johnathan, r = [-5 -6 -9.6+25.7i -9.6-25.7i]; p = poly(r) r1 = roots(p) % check p = 1.0e+04 * 0.0001 0.0030 ...

Solve for the constants of a Quartic given the complex roots?

Hi Johnathan, r = [-5 -6 -9.6+25.7i -9.6-25.7i]; p = poly(r) r1 = roots(p) % check p = 1.0e+04 * 0.0001 0.0030 ...

3 Monate ago | 0

| accepted

Answered

Coding a function for the Fourier Transform.

Hi Anthony, the only problem here is the normalization. For the inverse transform you are dividing by sqrt(N) every time, (N b...

Coding a function for the Fourier Transform.

Hi Anthony, the only problem here is the normalization. For the inverse transform you are dividing by sqrt(N) every time, (N b...

3 Monate ago | 0

| accepted

Answered

Ignoring NaNs for polyfit

Hello TimaMarie, yes, polyfit doesn't like NaNs. One way out is, just before doing polyfit, toss out the elements of both vari...

Ignoring NaNs for polyfit

Hello TimaMarie, yes, polyfit doesn't like NaNs. One way out is, just before doing polyfit, toss out the elements of both vari...

3 Monate ago | 0

| accepted

Answered

Find first item with a certain condition and use it, instead of finding all items with that condition

Hi Thomas, [After reading comments from Bruno and Rik I realized I forgot to mention that in order to get your code to run I ch...

Find first item with a certain condition and use it, instead of finding all items with that condition

Hi Thomas, [After reading comments from Bruno and Rik I realized I forgot to mention that in order to get your code to run I ch...

3 Monate ago | 1