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MaplePrimes Questions

Mean Reversion...

Asked by: MrMarc 3163
October 19 2009
0  11

I found on the internet a basic definition of mean reversion ( http://mathworld.wolfram.com/ReversiontotheMean.html )

I would assume such definition would also work as an definition of stationarity:
 

" Reversion to the mean, also called regression to the mean, is the statistical phenomenon stating that the greater the deviation of a random variate from its mean, the greater the probability that the next measured variate will deviate less far. In other words, an extreme event is likely to be followed by a less extreme event."

redefine some error...

Asked by: casperyc 962
October 19 2009
0  2

Hi,

errors such as

"Error, (in ImportMatrix) file or directory does not exist"
"Error, Matrix index out of range"

can I redefine the error message in a procedure?

say if "Error, (in ImportMatrix) file or directory does not exist" happens,

I want it to printf("You have not got the message yet.")

Generally, what shall I be looking for in the help in Maple?

 

Thanks.

casper

for what values (interval) of p...

Asked by: Lonely 400
infinity
October 19 2009
0  0

 

for what value or interval of p (-infinity < p < infinity) the following is valid

 

(1+x)^(m+1) > (1+x^m)* 2^m

 

here x > 1

save using the input varial as the file name...

Asked by: casperyc 962
input
October 19 2009
0  2

Hi,

 

myproc:=proc(name)
local i;
i:=10;
save i,"i_name";
end proc;

myproc(bob);

basically, I want to save the value i in the file that has name i_bob in this case.

how should I do that?

and dose it work the same way with Matrix? say I would like to Export a Matrix with name Matrix_bob, (or whatever I input in the myproc proceudre? )

 

Thanks.

 

How can I solve a system of Differential Algebraic...

Asked by: nmani 136
October 19 2009
0  3

I have a system of five big big big differential equations with a lot of Sin and cos. The system is not complex itself but we have complex  initial condtition?

How can I solve my system with maple with dsolve or something else?

 

Thanks

 

Crazy arctan answers to trigonometric equation and...

Asked by: GustavHj 88
document
October 19 2009
0  2

Have attached a worksheet with some questions about getting easy to read answers when solving a trigonometric equation and some other things using the context menu.

Pleas answer in an attached document since my Webb browser of some reason cannot read maple math in the forum.
Yours
Gustav

P.S. I use mapel 12

Many differential equations...

Asked by: torbensvendsen@mail.dk 8
October 19 2009
0  3

Edit: removed duplicate content (moderator)

read file that has '' in it...

Asked by: casperyc 962
October 18 2009
0  1

Hi,

How can I read a file that has " in the context correctly? (see the attached file)

Download 7845_not_good.txt
View file details

> read "notgood.txt";

Warning, incomplete quoted name;  use ` to end the name

on line 1, unexpected end of input

Error, while reading `notgood.txt`

 

Some problem with trig equations and factoring...

Asked by:
October 18 2009
0  0
I have attached a maple document with some questions.  Pleas answer in an attached document since my web browser of some reason cannot read maple-math in the forum.
By the way admin should take a look at the

problem with phaseportrait use of DEtools....

Asked by: Euclid 698
October 18 2009
0  4

question1:

DEtools[phaseportrait]

([diff(y(x),x)=-y(x)],y(x),x=-2.2,[[y(-2)=2],[y(-2)=1],[y(-2)=-2]],dirgrid=[17,17],arrows=LINE,axes=NORMAL);

This is the version in Maple 7?

After accessing to the help file,maybe it should be

with(DEtools):

phaseportrait(diff(y(x),x)=-y(x),y(x),x=-2.2,[[y(-2)=2],[y(-2)=1,[y(-2)=-2]],dirgrid=[17,17],arrows=LINE,axes=NORMAL);

but can't generate the resuls.

dirgrid seems not exist in the help.

 

question2:

how to generate n-Simplex elements ?...

Asked by: Euclid 698
plotting simplex
October 18 2009
0  4

http://en.wikipedia.org/wiki/Simplex

for what value the function is increasing and decr...

Asked by: Lonely 400
October 16 2009
0  6

 

for what value(s) of m the function is increasing (Xderivative > 0)/decreasing (Xderivative < 0):

 

m * log(x) / 2^m + (1-x^m) / (1+x)^m

som Matrix problems...

Asked by: casperyc 962
convert
October 16 2009
0  12

Hi,

I got some Matrix problems to ask:

First,

A:=Matrix(3,4,[[1,2,3],[4,5,6]]);

it will fill with '0's

A:=Matrix(3,4,[[1,2,3],[4,5,6]],fill=8);

it will fill with '8's

B:=Matrix(3,4,[1,2,3,4,5,6]);

it will fill with '0's

B:=Matrix(3,4,[1,2,3,4,5,6],fill=8);

it does not fill

what's the proper way to do it?

Second,

A:=Matrix(3,4,[1,2,3,4,5,6]);

convert(A,listlist);

[[1, 2, 3, 4], [5, 6, 0, 0], [0, 0, 0, 0]]

 

what if I want to have ONE single list as

FDTD(FEM/MoM/etc.) for EM/Heat Flow?...

Asked by: ihayles 56
October 16 2009
0  1

I have Maple 12, and not MapleSim.  Has anyone stumbled across something that "runs on top" of Maple that is similar to COMSOL Multiphysics that runs on top of MATLab?  I'd like to figure out (without writing the Maple code myself...) how to import some simple 3D geometries and run some (possibly symbolic, probably numeric) simulations of electromagnetic and heat flow phenomena.  COMSOL uses FEM.  Is this something MapleSim could do?  I don't need anything that'll do "real world" geometries (i.e.

Bifurcation Diagram...

Asked by: Nusc 499
October 15 2009
1  4

BIFURCATION DIAGRAM PROCEDURE
restart:
with(plots):
*xexpr is the logistic function to be iterated (we always start off at x=1/2, which will eventually attract).
*[ra,rb] is the range of the parameter.
*acc is the number of points sampled in [ra,rb]
Bifurcation := proc(initialpoint,xexpr,ra,rb,acc)
   local p1,hr,A,L1,i,j,phi:
   global r,L2:
   hr := unapply(xexpr,x);
   A := Vector(600):
   L1 := Vector(acc*500):

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