Was any one able to solve homework 2-6. We are supposed to use Matlab to solve a lossless transmission line input for a cosine segment and plot this using matlab.

maybe i daydreamed when he briefly put something on the board but NO where in the notes or the problem sets does he explain how to do this using MATLAB

1/29/2007 3:48:54 PM

I just used Matlab to mimic the approach taken in 2-4. You don't need any special commands, just a matrix and some for loops.

1/29/2007 4:06:46 PM

I still don't really understand the question. For 2-6 (and 2-5) you are looking at the wave at a certain point in time. So would you use for loops to make the proper matrix, then plot at the values of M requested?

Thanks

1/29/2007 5:47:27 PM

Pretty much. Figure out how big the matrix should be (M x N) and create an all zero matrix. Fill in the initial conditions and then use two nested loops to fill in the rest of the matrix. For the plots, just use the row that corresponds to the time you're interested in (e.g. M = 8 for 8 nsec).

The only tricky part is that the matrix should have dimensions of M by (N + 1) so that there is a v(m, n+1) term available when filling in the Nth column. When doing the plots in 2-6 you can just ignore the N+1 column. For problem 2-7 you're going to have to get rid of the N+1 column.

1/29/2007 7:32:04 PM

i honestly do not remember how to do all that stuff using matlab. its been a year and right now i am clueless.

1/29/2007 10:03:48 PM

Can someone explain the steps to solving 2-4, so that I can figure out how to solve 2-6 as well?

[Edited on January 29, 2007 at 11:03 PM. Reason : ]

1/29/2007 10:59:06 PM

fill in the matrix from time 3 to 9 using the x(t) equation, the variable is m,
then shift that line on like it has in the examples

did anyone get an error plotting the 3-d graph. my error says matrix must be square ...

1/29/2007 11:04:37 PM

^ Is m both m and delta t? Or is delta t 2e-9?

1/29/2007 11:07:24 PM

tm = m*delta t

m is just the index, so you have an m x n array,

you first fill column 1 and row 3 to 9 with x(t) as it is specified just plug in the m's
the each value shifted one column right and one row down, diagonally
and repeat over and over

1/29/2007 11:09:39 PM

^ Thank you so much.

1/29/2007 11:13:56 PM

does anyone have any sample matlab code form say 303, 301, or even 220. I would go to office hours to seek help but professor alexander's office hours is during one of my classes. I tried emailing the professor but he never responded. I am sure either way he would have some smart remark about why he wouldn't help.

2/5/2007 1:39:36 PM

http://www.mathworks.com/matlabcentral/ is a matlab user community and a great resource for finding code and seeing how people do things in matlab. i use it all the time.

[Edited on February 5, 2007 at 1:42 PM. Reason : d]

2/5/2007 1:42:20 PM