Hi,

restart;
.123456789*.123456789;
                                               0.01524157875

i need Maple to respond   0.015241578750190521 by adjusting Digits number dynamically. I don't want to adjust  the Digits Number to a fixed value.

Thanks!

OnesM:=Matrix(`%id`=119376536)

Anyone can solve this??

Many thanks!

Hi guys,
I want to import symbolic matrix from matlab to Maple, How I can do that ? 

How can I have a sequence as follow by using "seq" command?

x1,x2,...x200.

Please note that I need "xi" not "x_i".

Hey,

is there a way to substitute funktion combinations when they have the same arguments? I want to substitute abs(exp)*abs(1,exp) with exp. Algsubs works as long as I know the excat expressions. However, I want to do this substitution for any exp. Simplify doen't work here ether.

I also tried to write my own simplification rule with no success:

Download simplify_abs.mw

Thanks in advance!

Howdy,

I am trying to create a mathmatical model that shows a predator-prey relationship along with seasonal variations (hibernation). I made two piecewise functions where one is "on" during the winter and the other is "off" during the winter and the model worked well for one unit of time. 

My problem is that I would like the piecewise functions to apply over an arbitrary amount of time units periods without having to set the range within the function itself for 100 units of time. I was thinking that a for loop would work but i'm not sure how I would impliment that.

Thanks in advance!!

Edit: 

Here's a little bit more info on the problem.

I have three O.D.E's in an array..

ode := {r'(t),h'(t),c'(t)}

which are dependent on a list of parameters..

constants := {a,b,...,s,w,c0,h0,r0};

where s and w are my piecewise functions.

I am able to solve the three odes using dsolve for one period of s and w.

Again, I'm really not sure where to start to make my model periodic.

I'm running calculations like this:

    N:=10000;
    f := (i,j)-> (some complicated procedure depending on i and j);
    M:= Matrix([Threads:-Seq([Threads:-Seq( f(i,j), j=1..N)], i=1..N)]);

I have a server with 20 cores, but each core has two threads, so this code should max out all 40 threads. But what I notice is only at most 20 threads being used at a time. 

I checked kernelopts(numcpus) returns 20. 

Does anyone have any advice on how to maximize my resource usage?

Hi All,

Where can I download Fourier Series Package? I found other posts related to this but the link is not working.

Thanks.

I have the following sequence: n²/n²+31n+228.The question asks me to use an appropriate conditional statement to find N such that absolute (x_n-x₀)<epsilon for every n>=N. I found N but i don't know how to find it using Maple17.Can you please help me?

Is it possible to work with complex numbers in Maple T.A?

How could you for instance make a question where two complex numbers in polar form should be added. For instance (10<30deg)+(15<-10deg). I'm thinking of letting answers be in two fields, one for the absolute value and one for the angle but I would like to use random numbers in the two complex numbers to be added and would prefer to be able to use complex math in calculating the right answer.

Hi all!

as shown below, how can get a result without 'R':

p_com(z,t):=Re(exp(I*omega*t-I*k*(lambda[r]+I*lambda[i])*z)) assuming omega::real,t::real,k::real,lambda[r]::real,lambda[i]::real,z::real

Thanks very much!

I wrote the following procedure that evaluates i-th B-spline basis function of degree n over the knot vector T:

N := proc(i, n, t, T)

if (n = 0) then
    if ((t >= T[i]) and (t < T[i+1])) then
        return 1.0:
    else
        return 0.0:
    fi:
fi:

return (evalf((t-T[i])/(T[i+n]-T[i]))*N(i, n-1, t, T) + evalf((T[i+n+1]-t)/(T[i+n+1]-T[i+1]))*N(i+1, n-1, t, T)):

end proc:

Now, I want to compute

int(N(i, n, t, T)*N(j, n, t, T), t=0..1, numeric),

where i, n and T are given. However, Maple evaluates N and, since t is unknown, I get the following error:

"Error, (in N) cannot determine if this expression is true or false: .1 <= t and t < .25"

In http://www.maplesoft.com/support/help/Maple/view.aspx?path=evalf/Int  I read that in order to integrate a procedure, one should write (see the example given there)

evalf(Int(N*N, 0..1));

however, in my case, It will not work because I must pass the known parameters i, n and T. Is there a way to solve my problem?

Hi Guys, 

I'm trying to find stationary points of a numeric function. Any help would be appreciated. 

Assume I have a numeric function g(x). I'm attempting the following:

deriv:=(x)->fdiff(g(t),t=x); (I can't use the D operator as it doesn't like g(x))

Now deriv(x) <- Can be computed and computes the value quickly and easily. However plot and other functions require algebraic functions. I can plot this (with difficulty) via the following

plot(deriv,-10..10) <- This avoids converting to algebraic function and runs as a procedure. 

I can't use convert(deriv,algebraic) as it fails. 

I want to use the Student[NumericalAnalysis]Roots command, but it requires an algebraic function and I can't use the procedure trick which I did in the plot command. 

Does anyone know a better way of doing this? or is there a way I can write the numerical differivative as an algebraic function. (I've tried fsolve <- But this guy doesn't give me the correct answers generally). 

Thanks guys. 

Hey,

I want to assign a value to a symbol stored in a vector. I know the position of the symbol in the vector. Is there an easy way to do this?

Here to illsutrate my problem:

Download point_to_element.mw

Why does "eval(c, [b=1,l=1])" turn out to be "1" not "1/1+x"??? its driving me cracy. THX