Thread Subject: Problem 4d matrix irf

I have a 4d matrix irf(t,draw,var,lag), where t is time (173), draw(500) is a draw from a gibbs sampling, var(3) is a variable, and lag(21) is a lag. So the size of the matrix is 173x500x3x21.

But I need to convert it to a 3d matrix, where I want the mean of the 500x3x21 part converting to a 3x21 matrix, and put it in a 173x3x21.

How can I do this?

"Wildo " <wildogonzalez@yahoo.com> wrote in message <jgians$abk$1@newscl01ah.mathworks.com>...
> I have a 4d matrix irf(t,draw,var,lag), where t is time (173), draw(500) is a draw from a gibbs sampling, var(3) is a variable, and lag(21) is a lag. So the size of the matrix is 173x500x3x21.
>
> But I need to convert it to a 3d matrix, where I want the mean of the 500x3x21 part converting to a 3x21 matrix, and put it in a 173x3x21.
>
> How can I do this?

Why do I think that the function mean would be a
good start?

Of course, you might decide then that a 173x1x3x21
array was not what you wanted. So then if you think
about it, how could you use reshape to help here?

If that is more than you want, a little search might
find squeeze for you.

John

On Feb 4, 5:32 pm, "John D'Errico" <woodch...@rochester.rr.com> wrote:
> "Wildo " <wildogonza...@yahoo.com> wrote in message <jgians$ab...@newscl01ah.mathworks.com>...
> > I have a 4d matrix irf(t,draw,var,lag), where t is time (173), draw(500) is a draw from a gibbs sampling, var(3) is a variable, and lag(21) is a lag. So the size of the matrix is 173x500x3x21.
>
> > But I need to convert it to a 3d matrix, where I want the mean of the 500x3x21 part converting to a 3x21 matrix, and put it in a 173x3x21.
>
> > How can I do this?
>
> Why do I think that the function mean would be a
> good start?
>
> Of course, you might decide then that a 173x1x3x21
> array was not what you wanted. So then if you think
> about it, how could you use reshape to help here?
>
> If that is more than you want, a little search might
> find squeeze for you.
>
> John

You may think that John means to be mean,
but what he means is you should use mean.
And if you mean to use mean, you should carefully read
help mean