## Limit not calculated...

Hi, I was about to calculate the limit

limit(sin(x)+sin(y),{x=0,y=0})

and Maple 17 returns the same expression, with no answer.

What I am doing wrong?

## How do I force simplification of products of squar...

In an atomic physics calculation involving the quantum theory of angular momentum, there appear polynomials whose coefficients involve square roots of positive integers, for example

sqrt(6)-sqrt(2)*sqrt(3)

Maple does not cancel such an expression to zero because the code allows for the possibility that a square root can be positive or negative.  In the physics context all these square roots are positive.  Is there some simple way to induce Maple...

## subs batch expression...

Hi,

> seq(seq(p[j,c],j=2..3),c=1..3)=seq(seq(1/(1+exp(-(mu+cat(tau,j)+cat(eta,c)+mix[j,c]))),j=2..3),c=1..3);

Basically, I want to use these expressions in subs.

How do I tell Maple to make the substitution of "lhs=rhs"?

(in the form of {p[2,1]=something,p[3,1]=something,p[2,2]=something,p[2,2]=something,p[2,3]=something,p[3,3]=something,})

I can then use subs() to replace them in my desired expression.

Casper

## Is it really better? with(Threads)...

Hi all,

I just learned about the with(Threads) package and I wanted to do a bit testing and see if it's 'faster' or more 'efficient'.

Test.pdf

This was done on a i7 940X (QuardCore) laptop.

I dont really see how it is better in a sense?

Or am I using Seq for the wrong purpose?

Casper

## Programming help (speed up, batch processing, opti...

Hi all,

I have been trying to improve my code to speed up a bit.

Here is the toy example:

######################

restart:

myfunc:=proc(phi,p,CH)
# dummy code
# dummy code
# dummy code
# dummy code
end proc;

a:=myfunc(phi,p1,CH1)
b:=myfunc(phi,p2,CH1)
c:=myfunc(phi,p3,CH1)

ANS1:=w1*a+w2*b+(1-w1-w2)*b

a:=myfunc(phi,p1,CH2)
b:=myfunc(phi,p2,CH2)
c:=myfunc(phi,p3,CH2)

## bracket matching rectangular yellow box not appear...

I have bracket matching turned on but donot get the rectangular yellow box around matching brackets as shown in the attached picture. Can anyone help me how to turn this feature on for both input and output?

## How much is the student refund?...

When I was going through the process to purchase Maple 17 Student Edition it said something about a refund with valid confirmation of being a student. I was just wondering how much the refund is for.

## brackets and evalf...

Can somebody explain me this:

I created a null tetrad, but Maple's GRQuery returns false.  Here is the code:

## problem with solve...

Hello! I have the task to calculate the two angles of an 3d linkage. now in step 11 i have these two equations:

I have to solve these for phi, that is the angle I'm looking for. But the solution for phi should be indepented of psi. alpha and beta are variables. Everything else are known constant values.
What I tried: I solved Gl7 for psi (step 12...

## use of map and map2...

Hi all,

#####################################
myp:=proc(a,b,c)

local ans;

ans:=zip(`+`,a,b);

ans:=ans*c;

return ans;

end proc;
myp([\$1..4],[x,y,z,w],2);
map2(myp,[\$1..4],{[x,y,z,w],[x2,y2,z2,w2],[x3,y3,z3,w3]},4);

map2(myp,[\$1..4],{[x,y,z,w],[x2,y2,z2,w2],[x3,y3,z3,w3]},10);
map2(myp,[\$1..4],{[x,y,z,w],[x2,y2,z2,w2],[x3,y3,z3,w3]},0.5);

#####################################

Is it possible to use something like

## More efficient way? (quicker, less memory used, go...

Hi all,

##################################################################

restart:

K:=50;C:=20;

st:=time():

for j from 2 to K do
for c to C do
solve({log(cat(p,j,'C',c)/(1-cat(p,j,'C',c)))=mu+cat(tau,j)+cat(eta,c)+cat(mix,j,c)},cat(p,j,'C',c));
assign(%);
...

## Integral that Maple 17 cannot compute

by: Maple 17

Hi,

Here an example of integral that Maple 17 cannot calculate (mean of standard Gumbel distribution)

> G:=int(x*exp(-x)*exp(-exp(-x)), x = -infinity .. infinity);

The result is known as the Euler-Mascheroni constant as shown by a numerical computation:

> evalf(G);

0.5772156649

>  identify(%, extension = [gamma]);

gamma

> evalf(gamma)

0.5772156649

Also, it cannot compute the variance

## Import string and numerical data from txt.file...

Good morning everbody,

I am currently trying to get string and numerical datas from a txt.file but I don't get how to do this.
I have done this in matlab but I would like to make it in maple.
I have read other post about the subject and try tried this command:

``` fd := fopen(dataFile,READ,TEXT):