## MAJOR problem with precision in MAPLE do loops...

Dear Maple Specialists,

I deal with a major MAPLE problem the last months of my PhD.

PROBLEM:
My programm contains a do loop which calculates for given PsiS (purple color) and for a range of Psi1 and Psi2 (blue color) from PsiS to 0, values for the products Qsu1, Qsu2, Qtot .
The aim to calculate w(RLZ) which is obtained when the blue color loop is completed and Psi2 takes the final value 0.

## `evalf/int`, "external hardware float library coul...

After first tests with my brandnew Maple 16 (64bit) installation on Ubuntu Linux (12.04 Ubuntu Precise) I encountered the following error:

`evalf/int`, "external hardware float library could not be found/used"

when I run e.g.

evalf(Int(BesselJ(3,x),x=1..13,digits = 4,method = _d01ajc));

with OpenMaple

I wonder how to fix it.

I have

export MAPLE=...

and

export LD_LIBRARY_PATH=......

## accuracy of calculation in do loop....

Hello,

I want to calculate the IDs product :

## Ignoring values that are to small...

Hi,

i've been using evalf(Pi*5.6) for my calculations. after a few steps of calculations, some of the values are as small as 7.4x10-9 . These small values are insignificant to my calculations. how should i ask maple to ignore all the positive and negative values that are smaller than 1x10-9?

## Mechanics. Trajectory Plot...

`I am fairly new to Maple and trying to understand the dsolve command for numerical solutions and plotting graphs of radial distances and trajectory plots.`
`This is my code below. All of it successfully brings up a solution apart from the very last command and I don't understand why it is not working. `
`I believe the last plot is plotting a trajectory plot but I am not sure. I am meant to use the solution to plot the trajectory plot (X(t),Y9t))=(r(t...`

## Accuracy of substitution...

I have a question about the accuracy of Maple functions subs and evalf. I have some expressions such as the following: (more complicated). Let's call it f(n).  f(n) is not a polynomial in n or a rational function. It is a function of n involving exponents and four operations. When I plug in a large n in such an expression, would the answer I get (using evalf with some custom accuracy) be exact?  I am trying to prove f(n)/n >= constant....

## Matrix Evaluation...

What are the equivalents of eval and evalf for Matricies. In particular how would you display a Matrix which appears in symbolic form to appear with numeric entries.

## How do I get evalf to evaluate when two values are...

Hello,

I solved an equation, and Maple returns two values.  Even though I said, assuming v1i>0, the solve command returnse this:

## evalf rules: power...

logically evalf(x^(1/10)); should return x^(0.1000...0), not x^(1/10). Or it's just case of other rule?

## How does Maple evalutate geometric functions with ...

I would like to know how does Maple evaluate a geometric functions with evalf.

e.g.

evalf(sin(Pi/12));

`                          0.2588190451`

What method is used? I think about Taylor approximation, is it good idea? If not, I need to compare it with Taylor approximation.

## Newton's Method in Maple...

Hello,

I'm doing a math assignment for numerical methods and I had to answer a question - solving Newton's method in maple to submit. I need to solve the question to an accuracy of 10^-5. I don't have access to the software right now as I only have it on the computers at our school, but I did take a maple course in my first year of university and have some experience with it. I wrote up this formula, but I'm not 100% sure if its correct. Could someone...

## How to evaluate a user-defined function?...

I have defined a function 'A' and written a procedure to evaluate it for various variables, as follows:

A := r*sin(m);

Aval := proc (r, m)

evalf(A);

end proc;

Aval(1, Pi);

The function defined by its variables is returned:  r*sin(m).

How can I get maple to return the numerical value of the function?

## Numerical integration problem...

I have a problem with the numerical integration in Maple. Any help or suggestion will be greatly appreciated!

K[1] := 1.0;
K[2] := 1;
K[3] := 0.16;
nu:=-5.92;
alpha:=8;
y:=0.01;

dF:=proc(z,y)
local k,q,h;
q:=BesselI(alpha,z)/BesselI(0.0,z);
h:=2*(K[1]*q-y)/(K[3]+(K[3]^2+4*K[2]*z^2*K[1]*q-4*K[2]*z^2*y)^(1/2));
k:=-(K[3]^2+4*K[2]*z^2*(K[1]*q-y))^(-1/2);
z^nu*h^(nu-1)*exp(-1/2/h-z^2*h/2)*k;
end proc: