I have been trying to figure out a good way to work with z-transform expressions which display keeping everything in terms of negative powers of z. I am not using the z-transform procedure, but writing the equations directly by hand.

For example, given an expression a*z^(-1), Maple will output this as a/z. This is even more dramatic when dealing with rational forms in z^(-1).

The issue here is that z^(-1) has an explicit meaning in terms of delay blocks and causality.

If anyone has a nice way for Maple to return these in a pretty-printed fashion retaining the z^(-1) terms, that would be great. I still need to be able to manipulate the expressions algebraically.

 

Hi,

I would like to control the extents of my 3D parametric plot. Increasing the grid creates too many gridlines and I just get a black plot  (and I still don't get the extent in the y-coordinate that I want).

Any suggestions how I might be able to get this plot from -360 to 0 and -20 to 60 completely filled in? (see attached workbook).

Any suggestions on how to control the gridlines?

An idea of what I am trying to do...I want to plot argument(z/(1+z)) vs. argument(z)*180/pi vs. 20*log10(abs(z)) with contours of argument(z/(1+z)) and 20*log10(abs(z/(1+z))
This is a 3D plot of the output phase of a Nichol's Chart (with the output contours of the Nichol's chart).

Thanks.

phaseplot.mw

Hi,

I was wondering if anyone has a clever way to code the Cayley Omega process?
For those who are wondering, the Omega process is a differential operator. Given an n-dimensional space (x[1],x[2],x[3],...,x[n]), and n forms Q[1](x[1][1],x[1][2],x[1][3],etc) Q[2](x[2][1],x[2][2],x[2][3],etc) ... Q[n](x[n][1],x[n][1],x[n][1],etc), the operator is the determinant of the matrix who entries are the partial differential operators del/delx[i][j].

Thoughts? Suggestions?

Thanks.

I am trying to figure out how to simplify expressions like:

2^(6p+q) mod 3 (where p,q are variables representing integers)

Anybody know how to do this?

Even better would be something that solves 2^n=2 (mod 3) -> n=1 (mod 6)

Suggestions?

Hi,

I am having trouble getting a pattern match to the Heaviside function.

patmatch(Heaviside(x), Heaviside(a::algebraic))

returns "false" whereas I would expect it to return true.

On the other hand:

patmatch(Heaviside(x), Heaviside(x::algebraic))

returns true.

What am I missing?

Regards.