1:47 PM
Mike May: Checking to see if people are ready to log back into chat
Russell Blyth: In
Lynne Doty has joined this chat.
Leah Wrenn Berman has joined this chat.
Leah Wrenn Berman: we don't start for 45 minutes, though, right?
Lynne Doty: yes
Mike May: I was confused; We start at 2:30
John Boncek: Yes
1:50 PM
Matt Goeke has left this chat.
Parviz Khalili: What is the topic of the afternoon?
Mike May: We have a worksheet left from this morning to do, then we have 
several that I call "doing math without a net"
Mike May: The idea is that it can be quite powerful to set things up so that they 
work on random examples.
1:55 PM
Parviz Khalili: sounds interesting
Regina Souza: I would like to understand what is the logic behind the ``hidden'' 
sections onthe worksheet...
Regina Souza: It seems the contents of a section only appears when youexecute 
the last prompt on the previous section... How do you hide it?How do you know 
there is something hidden?
Leah Wrenn Berman: Did you try clicking on the triangle on the left 
hand side?
Regina Souza: no
Mike May: Maple lets you arrange worksheets with a structure and sections.
Leah Wrenn Berman: That should open and close the sections
Leah Wrenn Berman: Saves on clutter
Mike May: It then lets you close the sections so only titles are available.
Mike May: I like to organize worksheets so that they open like an outline, with top 
titles available at all time.
David Huckaby has joined this chat.
Mike May: It has the advantage of being able to close a section you are not 
concentrating on.
Regina Souza: where are the commands to save (and hide the content of the 
section)?
Mike May: I need to go to Maple to look at it and get the instructions correct.
Regina Souza: ok - and the little triangles are the clues that something is hidden?
2:00 PM
Mike May: With Maple open there are icons on the top row. About 6 over is a T 
for text insertion. Two over from there is an indent and outdent icon. These help 
create sections.
Regina Souza: I finally saw that the `triangles' are in fact arrows
Regina Souza: so you hightlight the sections and click > (enclose the sections)
Mike May: On Maple 9.5 the "triangles" were boxes.
Mike May: Correct RS
Regina Souza: I see
Leah Wrenn Berman: and I'm using a mac, so what I see as gray filled-
in triangles may look like something else to you!
Regina Souza: in my PC they are also grey filled "triangles" too
Dennis Keeler has joined this chat.
Leah Wrenn Berman: good to know
John Boncek: Mike -- Do you plan on using the "Classic Worksheet" or the new 
interface for Maple 10?
2:05 PM
Leah Wrenn Berman: Anybody know if there's a keyboard shortcut to 
enter greek letters in maple 10?
Mike May: For the most part I will use the new interface. There is a technical issue 
here. Classic on a PC runs a different image. The classic image never did make it to 
the mac.
John Boncek: Oh -- good to know. I need to see what happens on Linux
Mike May: On the other hand, I tend to lag a version or so on use of new features. I 
wait until the feature is mature, and also until I have had a chance to think through how 
to use it.
John Boncek: leah: Go into the "Help" menu, and do a glossary search on Greek
Mike May: The net effect is that I will mainly use "classic features" with the new 
interface.
John Boncek: oops..leah: Topic search
Mike May: Leah, have you seen the palette Greek on the left?
Leah Wrenn Berman: Mathematica's got a nice feature where you can 
use an escape sequence and get the greek letter in your input as 
well as your putput; guess I just have to type the name in maple
Leah Wrenn Berman: yep
Leah Wrenn Berman: thanks
2:10 PM
Mike May: One of the deciding factors here on Maple over Mathematica is frankly 
Mathematica has always been several times more expensive.
Leah Wrenn Berman: yeah...but it's what I do all my research with! So 
occasionally I have bad reflexes for maple
Mike May: I remember looking at a comparison a few years back. They had 
seemed togo out of there way do adopt different conventions, [] vs () and the like.
Parviz Khalili: When are we going to start?
Leah Wrenn Berman: except all the LinearAlgebra package commands 
are basically the Mathematica commands (except for [ ] --> ( ) )
Leah Wrenn Berman: it's very strange
Mike May: We are supposed to start at 2:30. Not everyone is back yet.
2:15 PM
Mike May: LB, There has also been a transition in Maple over the past several 
versions.
Mike May: They have gone to a programming structure called modules and are 
moving to standard CS naming conventions. (Full words used with camel case 
capitalization.
Mike May: The comparison is linalg vs LinearAlgebra.
Leah Wrenn Berman: ah, so it's not just for the LinearAlgebra package
Leah Wrenn Berman: right
John Boncek: We can't afford mathematica here. I use Maple, and we've also 
been experimenting with MuPad under Linux (educational licensing of MuPad allows 
students to use it for free)
Daniel Shown has joined this chat.
Leah Wrenn Berman: What's the difference for site licenses? I know 
that Mathematica is a little cheaper for a single academic license then 
Maple is (!)
Mike May: I find the LinearAlgebra conventions easier.
Leah Wrenn Berman: me too!
Mike May: It is hard to compare site license costs since you need to get quotes.
Mike May: I am going to start inviting other into the chat in preparation for 2:30.
Christian Hellings has joined this chat.
Harry Mills has joined this chat.
Suzanne Riehl has joined this chat.
David Thomas has joined this chat.
Hugh Sanders has joined this chat.
Steve Prothero has joined this chat.
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2:20 PM
Marius Buliga has joined this chat.
Harry Mills: URL for QT?
Steve Prothero: steve here -- my machine is running the system's Administrator 
Scan so I may be slow for a bit.
Marius Buliga: hi. what is the new url for quicktime?
Russell Blyth: For those here, VNC is up again
Russell Blyth: Same address
Russell Blyth: Video in about 2 minutes
2:25 PM
Michael Siddoway has joined this chat.
Harry Mills: Russell, the yellow font color for your name doesn't show up very 
well. I know it's you because you're the one I can't read. Heh.
Russell Blyth: Broadcasting video
Russell Blyth: rtsp://165.134.240.35/LA050627pm1
Russell Blyth: .sdp
Michael Siddoway: M Sidd set
Russell Blyth: sorry
Harry Mills: OK.. Ot
Harry Mills: sIt's just my machine that's choosing the color.
Tepper Gill has joined this chat.
Harry Mills: Gaussian Elim. the current topiic?
Tepper Gill: I am ready
Russell Blyth: rtsp://165.134.240.35/LA050627pm1.sdp for video
Russell Blyth: and VNC is the same as this morning
Russell Blyth: Anyone having issues?
2:30 PM
Russell Blyth: I want to suggest a modification to the video address for anyone 
who had issues this morning with slow video
David Thomas: Derrick says he has not been invited to the chat
Derrick Head has joined this chat.
Russell Blyth: Try adding :80 after the 35 in the address
Russell Blyth: That makes QT use port 80 instead of 554
Leah Wrenn Berman: made things much worse for me---I get Laurel
Leah Wrenn Berman: 's green screen
Leah Wrenn Berman: for much longer
Luz DeAlba has joined this chat.
Joyce Quella has joined this chat.
David Thomas: I find video better so far
Hugh Sanders: The video is better.
Michael Siddoway: Can you display a line of intersection intersecting a plane?
Michael Siddoway: OK
2:35 PM
Joyce Quella: Mike or Russell...could you post the stream URL again...we had 
some networking issues on this end
Dennis Keeler: rtsp://165.134.240.35/LA050627pm1.sdp
Harry Mills: In older Maple you'd do something like \alpha to get the greek 
in the output.
Harry Mills: Otherwise, alpha was just a long variable.
Frank Rooney has joined this chat.
2:40 PM
Alden Monberg has joined this chat.
Alden Monberg: I think so, but I don't know if I can hear you!
Harry Mills: How'd you obtain the 4x5 matrix in Exerciise 2? The one in the text 
part of the question...
Harry Mills: You're not there, yet.
Alden Monberg: What is the URL and what is the chicken number?
Leah Wrenn Berman: But as students, we don't know how to enter that 
matrix to convert it, eitehr!
Harry Mills: yes. Howzit displayed? Will wait 'til you get to it.
Regina Souza: Does it matter the order in which the variables appear? Or the 
format of the equations (solved for y, etc...)
Daniel Shown: vnc: 165.134.131.96
2:45 PM
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Dennis Keeler: qtrtsp://165.134.240.35/LA050627pm1.sdp
Harry Mills: That's nicer than 9.5
Alden Monberg: Are you sure?
Christian Hellings: Does that matrix template on the left work in the Maple Input 
mode too?
Harry Mills: Yes, Hellings.
Harry Mills: I just tested it.
2:50 PM
Russell Blyth: video off
Russell Blyth: video pm2 on
Russell Blyth: any problems?
Daniel Shown: the new video stream is 
here:rtsp://165.134.240.35/LA050627pm2.sdp
Russell Blyth: or questions?
Russell Blyth: hang on - video still not back
Tepper Gill: no video
Mike May: Harry, Yes I like the Matrix palette in 10 much more than in Maple 9.5
Mike May: We are having some technical problems and are reloading the video
Mike May: Video is back on
Russell Blyth: Any Qs?
Russell Blyth: or problems?
John Boncek: no audio yet here.
Tepper Gill: same here
Suzanne Riehl: I can see your computer screen -- but not your cursor. I'm guessing 
what you are refering to when you say "here" or "like this". Is there a way to see the 
cursor?
Lynne Doty: I have the same problem
Leah Wrenn Berman: at least on my computer, the vnc seems pretty 
laggy...
John Boncek: restarted QT -- i've got you now (audio)
3:00 PM
Harry Mills: N1?
Leah Wrenn Berman: from exercise 3
Leah Wrenn Berman: that we didn't do
Harry Mills: Got it.
Leah Wrenn Berman: For what it's worth, if you replace gensol:... with 
gensol := LinearSolve(M2, b, free=`t`);
Leah Wrenn Berman: you get rid of the stupid underscores on the 
parameters
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3:05 PM
Dorothy Zeiser has joined this chat.
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Harry Mills: Are we supposed to have this demo?
Mike May: Luz, OK?
Mike May: Yes
Dennis Keeler: it's in the PM section
Leah Wrenn Berman: http://euler.slu.edu/PREP05/program.html
Mike May: It's on the web site
Leah Wrenn Berman: 3rd in the afternoon list
Mike May: Yes, we've switched the order
Dennis Keeler: http://euler.slu.edu/prep05/ws/Demo-AlgorithmicGauss.mw
3:10 PM
Leah Wrenn Berman: This is really cool
Frank Rooney has left this chat.
Harry Mills: Can't "M[i] := RowOperation(M[i],[j,i],-M[i][j,i]/M[i][i,i]);" cause it to 
choke, if the divisor is zero?
Frank Rooney has joined this chat.
Harry Mills: heh
Harry Mills: Oh, so NOW you expect us to read stuff?
Mike May: :
3:15 PM
Harry Mills: No. I did that as an undergrad with MACSYMA
Harry Mills: No. The details get in the way. I like your thinking.
Mike May: Video down for pm3
Mike May: This is a tape switch as well as a new address
Harry Mills: I missed what the next sheet is going to be. I'm relying on my 
worksheet and the audio to get the point. The VNC moves too slowly.
Daniel Shown: rtsp://165.134.240.35/LA050627pm3.sdp
Leah Wrenn Berman: RandomMatrices.mw
Mike May: We're up
Mike May: Yes
Mike May: to LWB
Harry Mills: We're up. Oops. Sound cut out. Sound back. Good.
Mike May: HM: you'll be in good shape once the DVD comes out 
Dennis Keeler: will the DVD have a blooper reel? 
Mike May: 
Mike May: Maybe
Harry Mills: Leave ME out of it, Dennis.
3:20 PM
Hugh Sanders: The audio is down.
Harry Mills: I'm not. In fact, most of 'em are strictly less than min(rows,cols)
John Boncek: FYI: I've lost audio.
Hugh Sanders: Should I restart QT?
Mike May: We have audio, how widespread is the audio drop?
Mike May: HS: yes
Harry Mills: I may be misinterpreting something further down the 'sheet
John Boncek: restarting QT here, too
Lynne Doty: I'm running the worksheet in Maple10 and all 30 of mine have rank 
=min of rows,columns
Christian Hellings: My audio is fine, now.
John Boncek: ok...audio fine, no video
Michael Siddoway: Fine in Colorado
Harry Mills: My Equation (2.2) is what YOU're talking about, and the 3-tuples are 
as you described.
Hugh Sanders: Video is OK but no audio.
Alden Monberg has left this chat.
3:25 PM
Hugh Sanders: Still no audio.
Luz DeAlba has left this chat.
Leah Wrenn Berman: Why did you subtract col3?
Leah Wrenn Berman: sorry, a linear combo of col3
Leah Wrenn Berman: ok
Luz DeAlba has joined this chat.
Hugh Sanders: Is switching to port 80 accomplished by inserting :80 after the 35 in 
the address?
Mike May: yes
3:30 PM
Hugh Sanders: I still get the video but no sound.
Harry Mills: Subtle, but a nice point to make before Lebesgue theory.
Hugh Sanders: I have that address but pm3.
Hugh Sanders: OK
Hugh Sanders: My local audio seems OK, because the computer makes a noise 
everytime I get a chat message.
Hugh Sanders: OK
3:35 PM
Leah Wrenn Berman: When you say "stack a random m by n matrix on 
top of a basis for its null space " what do you mean?
Leah Wrenn Berman: in exercise 7
Hugh Sanders: No luck at this point.
Hugh Sanders: I closed down some QuickTime windows and restarted QuickTime 
and now I have sound.
Hugh Sanders: Yes, it was working before but instead of closing the QickTime 
windows I opened a new one each time and finally that was too much for the 
transmission.
Marius Buliga: what is yhe significance of minus {0}?
3:40 PM
Mike May: The zero vector gets stored as a number 0. THis has the wrong 
number of dimensions for the plot.
Harry Mills: Ah so. That makes your sequencing (Starting with vector spaces and 
subspaces) makes a lotta sense.
Leah Wrenn Berman: So, your book does rank early or linear 
transformations late?
Harry Mills: They start w/ vector spaces.
Harry Mills: This is a neat demo of the image of a transformation being a 
subspace.
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Christian Hellings: I like this random point idea a lot.
Harry Mills: I like it, too.
Lynne Doty: This is neat. Mine is easy to rotate to get a view that's clearly a plane.
Harry Mills: AND it reinforces that a 2-D subspace in R2 is a line thru (0,0)
Russell Blyth: video back on pm4
Michael Siddoway: Can you visually plot a line orthogonal to the null space?
Harry Mills: The "minus {0}" is set-theoretic subtraction, right?
3:45 PM
Mike May: Time to add some chatting. Any thoughts?
Leah Wrenn Berman: I've got a paper worksheet on determinants that 
would be a nice maple lab, i htink
Dennis Keeler: do you mind if I make something for Calculus instead?
Harry Mills: When's our assignment due?
Leah Wrenn Berman: and a better least-squares WS would be nice
Derrick Head: Since I teach ODE's, I have some ideas for linear systems of 
ODE's
Christian Hellings: Some of these mini-functions are very useful, like showplanes 
and the random matrix dtuff. I don't suppose there is a way to make these into 
"library" functions that are available in any new worksheet?
Tepper Gill: I need more time to work out the exercises, and get a better feel for what I 
can do in a controls course.
John Boncek: I was thinking about a worksheet on frames (lead-in to a talk about 
wavelets). Perhaps a demo on how frames are similar to bases
Steve Prothero: How about showing sensitivity to small changes in the coefficients 
in a simple system?
Harry Mills: Oh. Just one for the week. That should work out fine.
Dennis Keeler: I was thinking of Fundamental Theorem of Calculus - taking the 
derivative of the integral from 0 to x.
Lynne Doty: We have CS/IS majors and I wonder if I design Maple worksheets to 
get them to explore the geometric result of translations, rotations, shears.
Frank Rooney: How about something about invariants and the Cayley-Hamilton 
Theorem
3:50 PM
Harry Mills: OK.
Leah Wrenn Berman: Lynne, I've got a WS on that sort of stuff that 
needs a bunch of work that I can send, if you're interested
Harry Mills: OK. I've an old worksheet "Column space IS the range."
3:55 PM
Harry Mills: Nice use of optional arguments. *thieving*
Harry Mills: Yes, I mean to make off with 'em.
Harry Mills: Just lost sound.
Harry Mills: Just got it back.
Lynne Doty: This notion of reexecution of the same commands using controlled 
random input is really nice. Talk about making patterns easy to spot.
Mike May: Yes
Mike May: Good for asking students to form conjectures
Harry Mills: Yes. Like asking them to build (real) symmetric matrices and discuss 
the properties of the eigenvalues.
Harry Mills: Your students are fortunate to have you. I think this is really going to 
help me this fall, already.
4:00 PM
Mike May: Thanks
Harry Mills: Nice way of organizing things, with matrix, eigenvector and the 
product in lists.
Harry Mills: Nice job. I'll have my worksheets more ready to go tomorrow.
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Dennis Keeler: do you ever have trouble Pasting into a worksheet? I'm using 
Maple 10 on Mac OS X.
Harry Mills: Great.
Steve Prothero: Thanx for a good day.
Michael Siddoway: Thanks
Harry Mills: *bye* )
Hugh Sanders: OK
John Boncek: thank you....
Mike May: bye everyone
Christian Hellings: Thank you.
Parviz Khalili: see you tomorrow
Derrick Head: Thanks
Lynne Doty: Lots of useful and intriguing ideas.
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Marius Buliga: thank you. bye'
David Huckaby: Thanks! 
Dennis Keeler: thanks
Leah Wrenn Berman: night all
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Steve Prothero: has left the room
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Dorothy Zeiser: thanks
Dorothy Zeiser has left this chat.
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