Hello everyone,

I'm trying to solve the following nonlinear differential equation with the given boundary conditions.

I'm trying to compute the rank of large, non-quadratic matrices modulo p=2,3,5 and 7.

For matrix-sizes of (approx.) 20000 x 20000 everything works fine with Rank(p,M) of LinearAlgebra[Modular].

But for (approx.) 40000 x 40000 even the parsing of the matrix is not finished after 5 days (for 20k x 20k this takes 1 or 2 hours) . The system I use has enough ram, so no swaping is involved.

First question: I expected the parsing to be O(n^2), why is this not the case?

In matlab, a function is returned a structure H, say H.a, H.b, ...

In maple, I want to call this matlab function, but what returned to maple is a Record:

Hs:= getvar("H");

Hs:= Record(a=..., b=..., ...);

So how can I convert this record to a normal maple array? so I can access to each element by Hs[1]. 

Thank you

Kyle

I am traying to perform the followig operation:

For a giving vector A, where A=[1,3,5]  (defined as A=([1,3,5],datatype = float), calculate a vector B where:

B=[10^1,10^3,10^5].

I tried to use a for cicle to calculate B:

for i from 1 by 1 to 3 do  B[i] := 10^A[i] end do

The problem is that i dont get a Vectr B but 3 different number with the name B[1],B[2],B[3]. Just B is not defined.

Hi,

I am trying to fit data to a function. I used the funtion Fit() but the results werent right. This is what i did:

T := Vector([600, 800, 1000, 1200, 1400, 1600, 1800, 2000, 2200, 2400], datatype = float)

Kpco2F := Vector([1.22179966016487*10^20, 8.12830516164100*10^13, 1.66341265037017*10^10, 5.80764417521312*10^7, 1.03276140576140*10^6, 50815.9442560561, 4931.73803954936, 765.596606911256, 168.267406107047, 47.7529273657691], datatype = float)

I have run into some queer behaviour of my Maple 9 software. I gave the following commands:

##############################################################
 with(numtheory):
 xx := invcfrac([[0],[5,1,5,1,4,1]]);
                                        ...

Hi every one,

I am facing a situation here. Whenever, I sub n = 0 or 1, the following ode has a solution. 

But when I adopt other values except the above ones then the maple gives me the error

"division by zero". 

eq11:=(diff(((abs(diff(f(eta),eta,eta)))^(n-1)*diff(f(eta),eta,eta)),eta)

+n/(n+1)*f(eta)*diff(f(eta),eta,eta))=0;

resx:=dsolve({eq11,f(0)=1,D(f)(0)=0,D(f)(12)=0},numeric,method = bvp[midrich],

> f := a+D(x); 

> convert(f(t), diff);

Is there a way to tell Maple that "a" is a constant, so (t) won't attach to a? thanks, kyle

Hi there, I'm trying to pass some calculation to Matlab then retrive the result by getvar(), but seems something is getting wrong.

my matlab function is very simple:

function out =maple_fun(a, b)

out = a + b;

return

this function is saved as maple_fun.m.

in Maple,

restart:
with(Matlab):
openlink():
DirectoryLocation := " cd  '/Users/Kyle/Documents/MATLAB/'  ":

sol := dsolve(t*diff(phi(x),x$2)-x*diff(phi(x),x)+n*phi(x),phi(x));
phi := unapply(rhs(sol), x);
BC := [phi(0)=0,phi(1)=0];
with(linalg):
Ccoef := genmatrix(BC, [_C1,_C2]);
CharEqn := det(Ccoef) = 0;

restart;
sol := dsolve(t*diff(phi(x,t,n),x$2)-x*diff(phi(x,t,n),x)+n*phi(x,t,n),phi(x,t,n));
phi := unapply(rhs(sol), x);
BC := [phi(0,0,0)=0,phi(1,1,1)=0];
with(linalg):
Ccoef := genmatrix(BC, [_C1,_C2]);
CharEqn := det(Ccoef) = 0;

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This prompted me to install MapleV on my computer to properly view these applications however after installing, sadly we get a division by zero, overflow error message. 

Since probably no has done this in this day and age, this is a real stab in the...

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Briefly, the process consists in two layers of different materials (M1 and M2, thickness L1 and L2). The bottom part of the material M1 (z=0) is cooled down from Ti to Tf with the function T(0,t)=Ti-R*t (R is the cooling rate in °C.min-1) until T(0,t)=Tf. Here the equilibrium is reached in t=(Tf-Ti...