## numerical differentiation / fdiff...

Is there a way to use fdiff for functions, which allow only numerical input? It seems that fdiff is sending symbolics and that would not work in my case of interest (and I want to avoid to code such stuff, especially how to get the appropriate step size automatically ...). Related to Maple I only find this (general) source, but no according paper: M. Monagan, E. Cheb-Terrab A numerical differentiation routine for computing single, multiple and partial derivatives to arbitrary precision. This enables us to compute numerical values of derivatives of special functions for whic

## 3D Plot - Intersection of Plane with Sphere and Te...

Given is a sphere and a tetraeder. How can I (calculate and) plot the intersection of a plane with both objects? The intersection shoud be a circle and a triangle (in 2D or 3D). I tried a lot, but it didn't work out at all. The intersection command just works e.g. with two spheres. Many thanks for any help in advance!

## Using Maple's sum fuction to generate Legendre pol...

I have solve the Legendre equation (1-x^2)y''-2xy'+alpha(alpha+1)y=0. The solutions are: y1=1-alpha(alpha+1)x^2/2! +alpha(alpha-2)(alpha+1)(alpha+3)x^4/4! +sum{(-1)^m [(alpha-1)...(alpha-2m+2)][(alpha+2)...(alpha+2m-1)]x^2m/(2m)!} y2=x-(alpha-1)(alpha+2)x^3/3!+(alpha-1)(alpha-3)(alpha+2)(alpha+4)x^5/5!+sum{(-1)^m[(alpha-1)...(alpha-2m+1][(alpha+2)...(alpha+2m)]x^2m+1/(2m)!} I tried to obtain a Legendre polynomial, say P5(x), with Maple'sum function by plugging in the general expression but I do not obtain the correct answer. Can someone indicate how this can be done. Thank you kindly.

## Plots...

Is it possible with Maple to make contour plot of a function defined by its values in 2D grid?

## Passing arguments to proc...

Hello, how to write function such inc or succ in Pascal. This code  inc := proc(x) x := x+1; return x; end proc; A := 10; inc(A);  gives an error  Error, (in inc) illegal use of a formal parameter 

by: Maple

## Problem with spline integrating......

Hello! I have the cubic spline S=S(t) defined on 1<=t<=3, and I need to calculate such integral:int((diff(S,t)^2+1)^(1/2),t=1..3);
When I try to calculate this integral, maple8 says:"undefined"...
What is the problem?

p.s. maple code:
x:=[1,2,3];
y:=[1,0,2];
with(CurveFitting);
S:=spline(x,y,t,cubic);
int((diff(S,t)^2+1)^(1/2),t=1..3);

Thankful in advance, Max.

Hi, When I open maple and start a session I load a number of packages. For example: with(...) with(..) Now, when I open a new worksheet/file in the same session, do I have to reload the packages? TIA Larry Ciak

## Help on a plot problem, plot symbol, subscript...

Hi, I need some help on plot and I am still new. Hope someone can take care of my questions, thanks first! I want to plot a figure. And I want to the x-axis label shows \phi_1; and y-axis label shows \Pi. I want to show them with the subscripts "1 and t" And I want to show the figure title as "V_L=20, \gamma=1". Can maple do this? Thanks a lot!

## subsitution of a variable with a certain power in ...

Hi Everyone, I am trying to make a special substitution which neither  subs  nor  algsubs  seem to be able to make. I have long polynomials (maybe with 3000 terms), but for the sake of clarity here is an example with a short one: Poly:=a[1]^3+a[1]*a[3]^2+a[2]+a[1]*a[2]; Now I would like to substitute a[1] by a[1]^2, but only in the terms that have a[1] (to the power of one). (It is important that the a[1]^3 in the original Poly is not changed to a[1]^6 ). So after substitution the polynomial should become: Poly:=a[1]^3+a[1]^2*a[3]^2+a[2]+a[1]^2*a[2];

## displaying multiple plots...

why won't this display my graphs: g:=x->sin(Pi*x/6): h:=x->((7.4*10^22)/(3.84*10^8)^3)/((2*10^30)/(1.5*10^11)^3)*sin(4*Pi*x/(24+5/6)): A:=plot(g(x),x=0..24*7): B:=plot(h(x),x=0..24*7): display(A,B);

## Problem with localization of Maple 10 in Linux...

Hello everyone, I use Fedora Core 5 and Maple 10. When I try to open a file with comments in Russian in classic interface, instead of normal characteres I see strange symbols, in new java interface squares instead of characters. Moreover, cyrillic input doesn't work at all in the classic interface, and in the java interface it inputs only squares. Linux is fully localized, there are no problems with encoding in other applications. In WinXP there are no problems like that in Maple, but I have to use Linux. I can imagine that hardly someone of you had to face the problem, because the forum is in English, but nevertheless.....