Items tagged with evalf

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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.

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=......

Hello,

I want to calculate the IDs product :

 

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?

Please advice. Thanks

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...

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....

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.

Hello,

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

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

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.

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...

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?

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:

Hi:

I asked Maple to evaluate (using "evalf") an infinite sum and it says (very quickly) that the answer is identically 0 (not 10^(-7)).

When I numerically  evaluate a large number of terms of the sum, the answer gets smaller as the number of terms increases, so it seems that Maple is probably correct. The fact that the answer is immediate suggest that Maple is doing some analysis rather than adding a large number of numerical values.

I'd like to...

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