## MaplePrimes Posts

### Latest Post Latest Posts Feed

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It would be nice if maple (as run from a terminal) would add a couple of the Emacs keybindings. Support for Ctrl-[whatever] keys seems pretty good but there is no support for Meta keybindings. I tend to use these pretty regularly (quoted from bash man page): forward-word (M-f) Move forward to the end of the next word. Words are composed of alphanumeric characters (letters and digits). backward-word (M-b) Move back to the start of the current or previous word. Words are composed of alphanumeric characters (letters and digits).

## Bessel Functions and their integral forms

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If I attempt to evaluate the integral int(exp(I*z*cos(x)),x=0..Pi), I should get a Bessel Function, in fact J_0(x). But Maple does not do this, the way I use it. How does make maple10 recognize such integrlas?

## Labeling plotted points

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To my fellow maple user: I wanted to label critical point/s in plotted curve. For example: plot y=x^2 + 5. P(0,5)is the vertex. I like to label this point as "Vertex" on the plot itself. Thanks in advance for any assistance. pv

## PlanetMath

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In their own words ... "PlanetMath was conceived by Nathan Egge ("unlord" on PlanetMath) and Aaron Krowne ("akrowne" on PlanetMath-- yours truly) as a project to fill the void for a central repository for mathematical knowledge on the web, with a pedagogical slant. But we realized that we could do it in a way that would make it a community, built by the users, and that the users would be just as valuable as the content itself. There are now many grassroots-content sites like this (Wikipedia, Citeulike, Slashdot, Fark...), and PlanetMath represents a unique kind of hybrid of MathWorld, Wikipedia, and Slashdot concepts. We think that the end result has proven very useful to many people who are interested in learning math, who are already students studying math, or who make their living in mathematical professions."

## New Poll

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Now that we have Star Trek out of our system, we can go back to the business at hand. This new poll asks you about your favorite interaction mode with new Maple 10. T4.

## passing variable arguments (like from a loop index...

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Hello, I was hoping someone could suggest a way to add a index counter to the title of a Maple plot. I have some snapshots of an animation that I wish to include the value of the for loop/index counter in the title. Does anyone have any suggestions? I am using Maple 10. Thanks very much for any help, sbh.

## numsolve ode

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I would like to solve the following problem as stated below:

> ode3:=J=diff(E(x),x)*E(x)-diff((diff(E(x),x)),x);

> dsolve(ode3);

> odeplot(dsolve({ode3,D(E)(0)=2,D(E)(1)=2000},numeric,range=0..1),refine=1);

Error, (in dsolve/numeric/BVPSolve) initial Newton iteration is not converging

I have taken "J=2" doesn't matter too much for now. As you will see from the second command Maple can find an analytical solution to the problem. From my trials it seems that the initial condition D(E)(1)=2000 makes the problem, smaller values are ok. I have tried "Digits:=100" but this didn't help me. In the end it would be nice to go to larger (about 7 orders of magnitude) values for D(E)(1) in comparison to D(E)(0). Can you help me find a way to solve this problem?

## Implicit equation plotting

by: Maple
Can anyone help me please?! Cash Reward! My program solves my implicit equation but i am having trouble getting more than one result, ie, varying one of the variables. The best i can do is make a loop which gives a table of results which requires individually copying the results across into Excel for anysort of graph. Ideally i want to be able to plot the results in Maple, for any variable. This is for my 3rd year engineering project, any help much appreciated. > restart; > with(LinearAlgebra): > # IMPACT OF A FLUID FILLED SPHERICAL SHELL ("NON-HERTZIAN") WITH A "HERTZIAN" BALL-

## Substitution without evaluation

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To anyone: Please provide the syntax on how to substitute without maple evaluating the expression. For example if I have an expression x^2+2x+5. I want to substitute to the expression x=2. I want simply to see 2^2+2*2+5 without Maple evaluating the result preferably in maplet form. Thanks PV

## symmetric elliptic integrals

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Does somebody want Maple to support symmetric elliptic integrals? These are the Legendre elliptic integrals defined in terms of symmetric elliptic integrals. ELLIPTICF:=proc(x,k) x*R_F(1-x^2,1-k^2*x^2,1) end proc: ELLIPTICE:=proc(x,k) ELLIPTICF(x,k)-k^2*x^3/3*R_D(1-x^2,1-k^2*x^2,1) end proc: ELLIPTICPI:=proc(x,n,k) ELLIPTICF(x,k)+n*x^3/3*R_J(1-x^2,1-k^2*x^2,1,1-n*x^2) end proc: ELLIPTICK:=proc(k) R_F(0,1-k^2,1) end proc: ELLIPTICEK:=proc(k) ELLIPTICK(k)-k^2/3*R_D(0,1-k^2,1) end proc: ELLIPTICPIK:=proc(n,k) ELLIPTICK(k)+n/3*R_J(0,1-k^2,1,1-n) end proc: Jim FitzSimons

## Cannot determine expression

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Hello.

Can anybody explain me please this error? Thanx :-)

Error, cannot determine if this expression is true or false:

-2.500000000*exp(0.) <= -1.675000000

Program:

> restart:
> with(linalg):
> with(plots):
> with(DEtools):
> with(inttrans):
# Warning, the protected names norm and trace have been redefined and
# unprotected
# Warning, the name changecoords has been redefined
# Warning, the previous binding of the name adjoint has been removed
# and it now has an assigned value
# Warning, the previous binding of the name hilbert has been removed
# and it now has an assigned value

## Preview Messages

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Private messages allow the use of markup tags. However, the only action is "submit"; I cannot preview the message to ensure that my inserted markup is correct.

## Tricky "assume" problem?

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Here's a frustrating problem I've been having with "assume".
You'll see below that I assume that v'(m) >0 and v''(m) <>
Maple clearly remembers that v'(m) > 0 (as seen in the assumptions list and by looking at the first "is" in (4)), however, it now can't figure out that v'(m) > 0 implies !(v'(m) <>
Strangely, this worked perfectly fine before the additional assumption was added, and looking up the property (6) reveals the correct answer.
Moreover, maple seems to have two sets of assumptions on v'(m) (for six total assumptions, when I would expect four).

Any maple geniuses have an idea as to why Maple's "is" function is confused?

## ANY kind of vector graphics export

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Currently Maple doesn't offer any vector graphics export besides the slightly flaky postscript. I almost don't care whether it is pdf, svg, or for most windows users probably most preferable wmf. Please, get some into the next version. It may be the one reason why I hardly ever see Maple plots in a Powerpoint presentation. The bitmaps just look downright ugly, unless you blow up the resolution. Gregor

## Triangular matrix "forward substitution"??

Implement a computer program which, for a given lower triangular matrix A with the diagonal entries different from zero,finds the matrix inverse to A by solving the equations Axj= ej for j=1,...,n by the " forward substitution"
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