## brownstone down...

I'm aware that this probably is not the right place to post this, but is there anybody who can do something about brownstone.net being unreachable? I have to convert a BIG LaTeX-file this weekend for students to work on starting Monday and have been unable to connect for the past twelve hours or so.

## weird RegSubs...

I am trying to get students to solve inequalities. They have to enter intervals and I modify their response-string before processing it. Something weird happens when using RegSubs. I have reduced the behaviour to the following maple*-code: expr := convert("\$RESPONSE",string); with(StringTools); expr1:=RegSubs(",(.+)[)]"=",Open(\\1))",expr); evalb(expr1="(0,Open(1))"); This returns true when I enter "(0,25)" (without the quotes of course; you can replace 25 with anything you like). So, instead of the parenthesised .+, the \\1 just yields a 1. When I execute the code in my own Maple10, the correct substitution is made. I think our server runs Maple9. Any comment is appreciated.

## how to solve this equation?...

this is the differential equation of second derivative. because i learn Maple not long. the equation name is 'eq5' > eq5:=D(D(x1))=(a1*fx1+a2*gx1)*D(x1)+(a1*fx2+a2*gx2)*D(x2)+(a1*fxt+a2*gxt); x1(t),in the file. if you interesting ,just download the file to help me to solve this problem. regards. View 1984_diff equ.mw on MapleNet or Download 1984_diff equ.mw
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## Problem with document mode...

In document mode: 1) when i start a row with (math mode): 1+2 then press ctrl+= (and Maple intert the result 3) i can't continue writing on the same row 2) when i start a row with (math mode): 1/a then press ctrl+= (and Maple intert the result 1/a) i can continue writing on the same row why? Maple 10 last patch Thank you

## how to solve the differentiation in my work?...

i have a problem of my equation with differentiation,in the first i run it total OK ,but when i input the value into the equation, the ERROR was show the screen. i don't know which step have the problem in my procedure. under is my maple file,(if you can't understand what mean of this procedure,just send me E-mail). regards View 1984_new equation with water out.mw on MapleNet or Download 1984_new equation with water out.mw
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## pdsolve with point-by-point initial condition...

I'm numerically solving, using pdsolve on Maple 9, the diffusion-recombination equation. I'm interested in the long time behavior after a very short time excitation pulse. Ideally, pdsolve would have the capability to use a small time step for the initial part followed by a larger time step later. Otherwise, I could take the result of a calculation with a short time step as an initial condition for a calculation with a long time step. If anyone knows how to do either of those things, I would be grateful. Thanks, Richard

## Collapse document block...

The enclosed file has 2 document blocks. As far as I can tell, each block is identical except for the name of a procedure defined in it. When I go into Block A and select Format/Collapse Document Block, the procedure does not disappear. When I go into block B, it does. I'd appreciate it if someone could tell me why the difference. -Thanks View 2292_Georgeworksheet15.mw on MapleNet or Download 2292_Georgework

## Output numerical data from a Maplet?...

I have developed a Maplet tutorial in which the output of the Maplet Evaluate is an X-Y plot displayed using the Maplet Plotter element. I would also like the Maplet to display the numerical X-Y data in a format that would allow the students to simply copy and paste the data directly into an Excel document so that they can carry out additional analysis of the data. Any suggestions?

## Maple T.A. 2.5 can be started when the Fecora Core...

I installed Maple T.A. 2.5 on Fecora Core 4, and it can be started on the XWindow. I added the command "MapleTA_installed_dir/bin/mapleta.sh start" at the buttom of the script /etc/rc.d/rc.local, and I hopeed Maple T.A. service can be started when I reboot the system. But It doesn't work !! That means I have to go to the front of the machine, then I can start Maple T.A. service. It's very inconvenient for me. The following message is came from logs/mapleta.out loading... Root Empty Class loading... Maple T.A. Demonstration Class Exception in thread "main" java.lang.InternalError: Can't connect to X11 window server using ':0.0' as the value of the DISPLAY variable.

## fsolve returning just the equation and no answer...

Hi, I am trying to use fsolve to find the roots of p non-linear equations. These vary from 2 dimensional to, so far, 5 dimensional. I'm really trying to minimize the log likelihood of an ARCH time series: L := (t) -> 1/2*T*log(2*Pi)+1/2*Sum(log(h(t)),t = p .. T)+1/2*Sum(y[t]^2/h(t),t = p .. T): where h := (t) -> alpha + alpha*y[t-1]^2 + alpha*y[t-2]^2 ... + alpha[p]*u[y-p]^2: and y[t] are observed data. I've used the p partial derivatives to solve for dL/dalpha=0 using fsolve and intervals alpha=0..1. Occasionally, it works fine and estimates the parameter vector alpha reasonably. However, sometimes it takes about 30-60 seconds and just returns the equation and no answer:

## Maple 10 Formatting a table...

I have been creating a document and had to create a table. I made a mistake, deleted the table and then tried to redo it but I am not allowed use the following functions:table, plot, spreadsheet, and sketch. These four are now in very pale type. How can I recover them? Thank you. Blake

## Evaluate the frequency of a processor...

I'm currently working on a school project, the issue is to find approximately the speed of a processor. I made a script which gives the time necessary to calculate a big factorial (10000! for instance). This time (gived by the function time()) is the total CPU time needed to calculate this factorial. But know, I need to know the total number of processor cycle per instruction (CPI) necessary to calculate the factorial. I explain : maybe you already know that the processor run by cycles which has a link with the frequency of the processor. If i can evaluate the number of processor cycle necessary to make a multiplication or the calculation of a factorial (even if this number is approximate) I would be able to find the speed of my processor.