Ok, I have the following equations: c'[t] = a[t]*b[t]*k1 - c[t]*k2, a'[t] = (-a[t])*b[t]*k1 + c[t]*k2, b'[t] = (-a[t])*b[t]*k1 + c[t]*k2, c[0] =0, a[0] =10, b[0] =10. I have data for concentration of "c" at all time intervals from 0-16. Here is the data: {0, 0}, {1, 4.98112}, {2, 6.61986}, {3, 7.42423}, {4,7.89529}, {5, 8.20004}, {6, 8.41008}, {7, 8.56123}, {8,8.67342}, {9, 8.7586}, {10, 8.82442}, {11, 8.87595}, {12, 8.91671}, {13, 8.94923}, {14, 8.97535}, {15, 8.99643}, {16, 9.01351}. I need Maple to Solve the ODE's and optimize the values for k1 and k2 to fit the data usins a least-square method or something along the lins of that. Can someone send me the code for that?

We were wondering if you could help us with a question to Maple: We have converted a C code directly into Maple code and have found that Maple runs about a thousand times slower than the C version (the code is a numerical simulation). 1) Why is this so? 2) How do we make it run faster?

Hi, All, I'm a Maple primer. I want to solve an ODE numerically and then save the data to file. I use: dsol := dsolve({deq,ic}, numeric, range=0..100); or dsol := dsolve({deq,ic}, numeric, range=0..100, output=operator); then how can I print the formated data for some specified t (=1..100, for example) to a data file? Thanks. David

I need the symbol for the partial derivative (something like @) in a .mws worksheet. Well, I found this feature as an operator on the new .mw platform, but I need it as a symbol. If I write a name (say PartialD) in the worksheet I want to get the symbol similar to @ at the screen.

What can I do?

Florian

I would like to construct a maplet to evaluate different objects in general relativity, say for example , metric,covaliant derivative and so on. Please help me with the procedure or a sample maplet.

I'm wondering what I'm missing here: with Student[Calculus1]: InflectionPoints(x^(5/3) - 5*x^(2/3),x) returns an empty result where there should be an inflection point at (-1,-4). I suppose there is a real easy solution to this. Please enlighten me. Tim

When simplifying an expression or solving an equation, is there a way to have Maple display some of the steps without having to put them in manually?

Is it possible to generate C or Fortran code for a numerically evaluated integral (ie. evalf(Int(...)) )? with(CodeGeneration): and either C(..) or Fortran(...) yield the error message: Warning, the function names {Int} are not recognized in the target language (a similar error message occurs for an int(..) expression) Alejandro

A student in my PDE class asked about having two functions in animation at the same time. Here is how I suggested doing this: > f:=(t,x)->sin(t)*x*(1-x); > g:=(t,x)->cos(t)*x*(1-x); > N:=50; > for n from 0 to N do J[n]:=plot([f(2*Pi*n/N,x),g(2*Pi*n/N,x)],x=0..1): od: n:='n': > plots[display]([seq(J[n],n=0..N)],insequence=true); Is there a simpler way? Jim Herod

I am trying to determine when one inequality implies another inequality and I am finding that assume and assuming aren't working consistently for me. I've put the code for my test run below. It seems to work the first time through when I assume mylist[1], but when I assume mylist[2] it always returns false. If I explicitly test is(x>-4) it returns true as it should but if I ask it to determine is(mylist[5]) (which is x>-4 once mylist is overwritten) it returns false? Is there a reason for this? I'm eventually going to need to put it all into a loop that works for any list--is there a way that will guarantee that it will work consistently?

Why don't these structured types work? > type(Pi, symbol); > evalb(Pi::symbol); > type(Pi, constant); > evalb(Pi::constant); > type(x, symbol); > evalb(x::symbol); > type(x, constant); > evalb(x::constant); > type(Pi, symbol and not constant); > evalb(Pi::(symbol and not constant)); > type(x, symbol and not constant); > evalb(x::(symbol and not constant)); I know we can do it using TypeTools[AddType]( variable, t->evalb(t::symbol and not t::constant) ); but why doesn't the simple version work? Phil

How do I extract an element from a list in a Maplet? In Maple, if I wanted the 1st entry in list A, I'd just use A[1]. In a Maplet, the output of a DropDownBox is a list containing a string, but 'DDB'[1] seems to make no sense to the Maplet.

I want to distribute a collection of Maple-related materials to students or other users. One of the "documents" is a Maple worksheet that contains a hyperlink to other material in the distribution. So, I want to have a URL hyperlink reference to, say, "./web/mystuff.html". It appears to me that Maple's hyperlinks are designed for use only with static, and external, websites. The hyperlink properties popup dialog does not allow me to browse to a local file; I can only browse to a worksheet or maplet. I can get around this limitation by manually editing the worksheet file. I can give an explicit path to the file but I have been unable to find a way to use a relative path to the file.

How can I get a Maplet to output a simple real number? What I'm trying to write simply asks for a real number, which will then be used in a worksheet after the Maplet is called. A better question might be, How can I extract a number from a string? Since Maplets appear to output ["123.456"] -- How can I assign the 123.456 to a variable? Thanks, Shannon

Hello, A Maple user sent me a technical support e-mail today with questions about calculating prime numbers, and I thought that it would be worthwhile to post the questions in this forum for our community to answer. The questions are: 1. What is the "best and final" algorithm to find a prime number in Maple? 2. How can you use Maple to calculate the last Mersenne prime number? Bryon Thur Manager, Business Information Systems Maplesoft