When I try to integrate a function,Maple returns a summation sign and underneath this sign is the expression R= RootOf (      ),where the bracket contains a cubic polynomial written in terms of Maple's internal default variable _Z.  Why can't Maple simply evaluate the roots of this cubic equation and return the value to me? What do I have to do to force Maple to return the desired result? 

AntipodeanMan

Hi there,

fsolve fails me, for the first time. I have this very messy expression, which comes out of a cubic equation. It must have a zero. I plot it and the graph, smooth, shows a zero between 16.4 and 16.5, but maple's fsolve fails to find it, why's that? The slope of the function is very flat near the zero. I tried to tell maple the solution is between 16.4 and 16.5, to no avail.

Any advice will be much appreciated. The following code tells it all.

many thanks,

Patrick.

I am having problems using implicitplot.  I run this code and it worked and today I tried it again and it gives me the following:

with(plots,implicitplot);

implicitplot(0=int(erf(  (T-e*t)/sqrt(2)  )*t^2*exp(-t/2),t=0..infinity),e=0..1,T=0..10);

Error, (in plots/implicitplot) invalid input: the following extra unknowns were found in the input expression: {t}

The weird thing is that this worked before (took about 10min though) and now it isn't.  Any suggestions?

Thanks

May be that some other people want to use pattern-matching techniques in wrong ways or contexts. What I am interested in is much simpler and clear.

Using dsolve gives the incorrect solution unless you force it to use Laplace transforms. 

Notice that Y5 is the correct solution, not the Y coming from dsolve.

DE17:=diff(y(t),t$2)+y(t)=Dirac(t-Pi)+Dirac(t-2*Pi)+Dirac(t-3*Pi);
Y:=dsolve({DE17,y(0)=0,D(y)(0)=0},y(t));
plot(rhs(Y),t=0..6*Pi);
with(inttrans):
Y2:=laplace(DE17,t,s);
Y3:=solve(Y2,laplace(y(t),t,s));
Y4:=subs({y(0)=0,D(y)(0)=0},Y3);
Y5:=invlaplace(Y4,s,t);
plot(Y5,t=0..6*Pi);
 

 

Anybody run into this problem before?

View 8340_helpweaklynonlinear.mw on MapleNet or Download 8340_helpweaklynonlinear.mw

A colleague recently showed me some strange behavior when trying to plot vertical lines. The following works to create the unit square:

plot( [x=0,x=1,0,1], x=0..1, y=0..1, color=black, axes=none ); # OK

But doubling the size in each direction does not produce a square:

plot( [x=0,x=2,0,2], x=0..2, y=0..2, color=black, axes=none ); # BAD

The vertical lines extend only up to y=1, not y=2 as requested. The next command shows that vertical lines at the boundary are treated differently.

How do I change the default font used in Maple 12?  I'm in WinXP.

Hi, I am just wondering who is currently using Maple in Finance. While I would keen to know any commercial or academic uses, I am especially interested in two areas: 1. Asset valuation and modelling 2. Portfolio analysis including risk, hedging, rebalancing or optimisation 3. High frequency (from 15min to readtime) processing of data (FX, Equity or IR) We recently completed a quite extensive benchmarking of Maple, Mathematica and Matlab using finance and portfolio related problems and would be interested know other experiences here.

I have been wondering about the reception of an independent patch Library for Maple.

I'll lay out a few ideas, and then maybe some criticism (or indifference) might follow.

I'm a bullet-point sort of person:

• sourceforge project with a few willing experts for vetting and gatekeeping of submissions.
• Patch .mla Library archive, going into /toolbox/Patch/lib/ so as to get picked up automatically by libname.
• Self-building, with...

I have been thinking about creating a Maple benchmark, to show a performance ranking versus operating system and hardware.

Is there any interest in such a thing?

If the results were put in a mapleprimes blog post, then they might be editable, and so could be updated as more items were submitted (messaged or emailed, to me, say).

After having Maple for a week I'm happy with it but still have to learn a lot about the kinds of problems it can solve.  Here is a problem I solved many years ago whose solution I have misplaced.  I'm wondering if Maple could help me recover my solution.

Write an expression for ab (a and b real) using only the unit (1) and the operations of adding, subtracting, and taking the reciprocal.

I'm also curious whether this is a well-known problem.  As I recall, I didn't find any references to it when I worked on it before.

 

Something I've been wondering about...

i am solving a heat equations with maple but i didn't work out. if you guys can get it out plz give me code. thanx a million

diff(u1(x,t),t)=diff(diff(u1(x,t),x),x))-a*(u1(x,t)-u2(x,t))+b*(u3(x,t)-u1(x,t))
diff(u2(x,t),t)=diff(diff(u2(x,t),x),x))-c*(u2(x,t)-u3(x,t))+a*(u1(x,t)-u2(x,t))
diff(u3(x,t),t)=diff(diff(u3(x,t),x),x))-b*(u3(x,t)-u1(x,t))+c*(u2(x,t)-u3(x,t))

i need the expression of the u1(x,t)，u2(x,t)，u3(x,t) and the a,b,c are constants.

Looking forward to hearing from you!!!

 

I've just reformatted my computer and NEED to reinstall Maple 11 ASAP,
assignments are due soon.
I am having trouble installing it

1st time Installing)

   Everything was alrite until my cd-drive went haywire and the installiation frooze
   i then ended the task (task manager), maple as far as i know created the folder 
  program files, a few files there but NO WORKING PROGRAM is there leading to my second attempt to reinstall

2nd time installing)

"Maple 11 already installed"
  confused i decided to explore maple 11 folder, attempt an uninstall