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I am stuck in making the pentadiagonal matrix A

This sort of thing is a BAD idea: A = A+spdiags(s_vec, 0, (nx+1)*(ny+1), (nx+1)*(ny+1)); % Add s to the main diagonal of A XX_...

I am stuck in making the pentadiagonal matrix A

This sort of thing is a BAD idea: A = A+spdiags(s_vec, 0, (nx+1)*(ny+1), (nx+1)*(ny+1)); % Add s to the main diagonal of A XX_...

15 jours il y a | 0

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Find the derivative of a spline curve obtained using cscvn

No. There is no simple "function" of a spline. It is a mess of coefficients that by themselves are fairly meaningless to those w...

Find the derivative of a spline curve obtained using cscvn

No. There is no simple "function" of a spline. It is a mess of coefficients that by themselves are fairly meaningless to those w...

16 jours il y a | 0

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Fitting powerlaw between two points

Given two points exactly, thus: yx = [0.047 100; 0.0382 0.1933]; y1 = yx(:,1); x1 = yx(:,2); You want the power law cur...

Fitting powerlaw between two points

Given two points exactly, thus: yx = [0.047 100; 0.0382 0.1933]; y1 = yx(:,1); x1 = yx(:,2); You want the power law cur...

16 jours il y a | 0

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How to combine the trapezoidal rule with interpolation in ode23t function

A FREE interpolant is one where the nodes are not fixed in advance. For example, suppose I choose to interpolate sin(x), on th...

How to combine the trapezoidal rule with interpolation in ode23t function

A FREE interpolant is one where the nodes are not fixed in advance. For example, suppose I choose to interpolate sin(x), on th...

16 jours il y a | 0

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How to get the combination "nCk", if either n or k is a variable.

if x(3) is NOT an integer, then what do you expect? If x(3) is NOT at least as large as d, then what do you expect? In either...

How to get the combination "nCk", if either n or k is a variable.

if x(3) is NOT an integer, then what do you expect? If x(3) is NOT at least as large as d, then what do you expect? In either...

16 jours il y a | 0

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Fitting 3D data into a function

The curve fitting toolbox does not fit models with more than 2 independent variables. You can use my polyfitn tool, found on th...

Fitting 3D data into a function

The curve fitting toolbox does not fit models with more than 2 independent variables. You can use my polyfitn tool, found on th...

17 jours il y a | 1

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How to solve exponential variables

The problem is, you have been trying to SOLVE them. More approproately, you want to use a tool that will FIT your model to the...

How to solve exponential variables

The problem is, you have been trying to SOLVE them. More approproately, you want to use a tool that will FIT your model to the...

17 jours il y a | 0

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Laguerre polynomials of large degree.

If you are using double precision, then OF COURSE high order polynomials of any form in MATLAB should not be trusted!!!! At leas...

Laguerre polynomials of large degree.

If you are using double precision, then OF COURSE high order polynomials of any form in MATLAB should not be trusted!!!! At leas...

21 jours il y a | 1

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Shifting an array without circshift

Nobody can know what you did wrong. circshift DOES work. I'm not even sure what you would have done that would cause an error. T...

Shifting an array without circshift

Nobody can know what you did wrong. circshift DOES work. I'm not even sure what you would have done that would cause an error. T...

21 jours il y a | 0

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trying to solve two non-linear simultaneous equations but I had an error figuring out my two unknowns (X(1) &x(2)) , can anyone pls help?

ARGH. Why would you post a picture of your code? And at that, only a partial picture? Even if I try to show why your code fails,...

trying to solve two non-linear simultaneous equations but I had an error figuring out my two unknowns (X(1) &x(2)) , can anyone pls help?

ARGH. Why would you post a picture of your code? And at that, only a partial picture? Even if I try to show why your code fails,...

23 jours il y a | 0

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How to determine concavity point?

You give no data, so I'll need to make some up for an example. x = linspace(-30,30,500); y = cumsum((atan(x - 10)/2 + 1)); pl...

How to determine concavity point?

You give no data, so I'll need to make some up for an example. x = linspace(-30,30,500); y = cumsum((atan(x - 10)/2 + 1)); pl...

24 jours il y a | 0

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What to be chosen c so that all elements of matrix B will be a round number. B=A.c; where A is the matrix of non integers.

You want to find some scalar value c, such that for some given vector A, you want the product A*c = B to be purely a vecto...

What to be chosen c so that all elements of matrix B will be a round number. B=A.c; where A is the matrix of non integers.

You want to find some scalar value c, such that for some given vector A, you want the product A*c = B to be purely a vecto...

27 jours il y a | 2

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How can i simulate a generic poisson process?

Not sure how you built the vector. Is it a Poisson process? Could be. :) As I recall, if you have exponential inter-rarrival tim...

How can i simulate a generic poisson process?

Not sure how you built the vector. Is it a Poisson process? Could be. :) As I recall, if you have exponential inter-rarrival tim...

28 jours il y a | 1

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mvncdf gives different results before and after the variable is standardised

No answer yet? The distinction as I see it is a subtle one. And had your covariance matrix been a diagonal one, then I expect it...

mvncdf gives different results before and after the variable is standardised

No answer yet? The distinction as I see it is a subtle one. And had your covariance matrix been a diagonal one, then I expect it...

28 jours il y a | 0

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Delete a plane (2d) within a 3d matrix

Sometimes it is simpler to take what you want, than it is to delete what you don't want. Here is a matrix: A = rand(256,256,256...

Delete a plane (2d) within a 3d matrix

Sometimes it is simpler to take what you want, than it is to delete what you don't want. Here is a matrix: A = rand(256,256,256...

29 jours il y a | 0

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How do I find the (right) null space of a matrix?

Easy. A = rand(5,2)*rand(2,3) A has rank 2. Arnull = null(A) A*Arnull It kills A, which is what the right nullspace would d...

How do I find the (right) null space of a matrix?

Easy. A = rand(5,2)*rand(2,3) A has rank 2. Arnull = null(A) A*Arnull It kills A, which is what the right nullspace would d...

30 jours il y a | 0

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asking for a polynomial expression in an input

Can you type in a polynomial? Why not? You type it anyway. Just use input, which can return the result as a string. Or, use a di...

asking for a polynomial expression in an input

Can you type in a polynomial? Why not? You type it anyway. Just use input, which can return the result as a string. Or, use a di...

environ un mois il y a | 0

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How do i keep track of eigenvalue on pzmap for a pariticular system matrix A containing a variable D?

You can use the tool I wrote, eigenshuffle. It sorts the eigenvalues in as consistent an order as possible, by assuming the corr...

How do i keep track of eigenvalue on pzmap for a pariticular system matrix A containing a variable D?

You can use the tool I wrote, eigenshuffle. It sorts the eigenvalues in as consistent an order as possible, by assuming the corr...

environ un mois il y a | 0

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Error using "*" in my equation, assumes I am trying to do matrix multiplication.

Even though you are not using matrices, does not mean that linear algebra could not be intended. MATLAB does not know what you a...

Error using "*" in my equation, assumes I am trying to do matrix multiplication.

Even though you are not using matrices, does not mean that linear algebra could not be intended. MATLAB does not know what you a...

environ un mois il y a | 0

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Finding the turning points

If all you will use are the 100 coarsely sampled points you are plotting, then min and max will do what you want. Look at the se...

Finding the turning points

If all you will use are the 100 coarsely sampled points you are plotting, then min and max will do what you want. Look at the se...

environ un mois il y a | 0

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surface area of 3D surface

Would our doing your exam for you really help you? Seriously? If you need help that badly, then you should have been studying mo...

surface area of 3D surface

Would our doing your exam for you really help you? Seriously? If you need help that badly, then you should have been studying mo...

environ un mois il y a | 0

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How do I place a point anywhere along x axis (with range 100m) in a plot?

Highly confusing. Do you want to plot a single point? What y value? Maybe you want to do this? k = 53; plot(k,0,'ro') % A sing...

How do I place a point anywhere along x axis (with range 100m) in a plot?

Highly confusing. Do you want to plot a single point? What y value? Maybe you want to do this? k = 53; plot(k,0,'ro') % A sing...

environ un mois il y a | 0

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Cantor function in matlab

To be honest, I'd probably be lazy, and just use the simple algorithm found in wikipedia. https://en.wikipedia.org/wiki/Cantor_...

Cantor function in matlab

To be honest, I'd probably be lazy, and just use the simple algorithm found in wikipedia. https://en.wikipedia.org/wiki/Cantor_...

environ un mois il y a | 1

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Wrong answer for ODE

As is so often the case, a DIFFERENT answer is not always a WRONG answer. It may just look different. But different is not alway...

Wrong answer for ODE

As is so often the case, a DIFFERENT answer is not always a WRONG answer. It may just look different. But different is not alway...

environ un mois il y a | 0

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function of two uniformly random variables

I think you need to learn how to write a function. You also seriously need to learn about the dotted operators. What you wrote f...

function of two uniformly random variables

I think you need to learn how to write a function. You also seriously need to learn about the dotted operators. What you wrote f...

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Create a series of variables with names that include numbers

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval The funny th...

Create a series of variables with names that include numbers

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval The funny th...

environ un mois il y a | 0

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Can we trace the qualification of person using matlab?

Huh? If I had to guess, you want to see if an algorithm exists to know the degree of skill a person has as a MATLAB coder, based...

Can we trace the qualification of person using matlab?

Huh? If I had to guess, you want to see if an algorithm exists to know the degree of skill a person has as a MATLAB coder, based...

environ un mois il y a | 2

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Non linear fit of y=f[x] where y can have multiple values for a single value of x

No. You cannot use polyfitn. It is designed to solve a SINGLE valued problem, but with 1 or more independent variables. You cann...

Non linear fit of y=f[x] where y can have multiple values for a single value of x

No. You cannot use polyfitn. It is designed to solve a SINGLE valued problem, but with 1 or more independent variables. You cann...

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How to give a condition based on the following situation

Why does it matter? Just pick one of them. Or choose randomly between them. Or on odd numbered days, choose the first, on even n...

How to give a condition based on the following situation

Why does it matter? Just pick one of them. Or choose randomly between them. Or on odd numbered days, choose the first, on even n...

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How to replace the non zero values of a matrix with another value?

A(A ~= 0) == 0.1; One line of code. That applies to ANY release of MATLAB. As far back as I have been using MATLAB, so only bac...

How to replace the non zero values of a matrix with another value?

A(A ~= 0) == 0.1; One line of code. That applies to ANY release of MATLAB. As far back as I have been using MATLAB, so only bac...

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