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:

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

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

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

In my previous posts I have discussed various difficulties encountered when writing parallel algorithms. At the end of the last post I concluded that the best way to solve some of these problems is to introduce a higher level programming model. This blog post will discuss the Task Programming Model, the high level parallel programming model introduced in Maple 13.

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):

Hi,

I am trying to generate a non-singular Matrix.

> KeyMatrix:=Mod(127,RandomMatrix(n),integer);
> if Determinant(127,KeyMatrix)=0 then
> Return(KeyMatrix);
> fi;

Basically, it asks Maple to return to
KeyMatrix:=Mod(127,RandomMatrix(n),integer);
again if the current one if not invertible.

however, i have confused myself with RETURN and return

which is should i use?

thanks

casper
 

What is the pattern in the following polynom: (how to generate them) 

1:     12 n^2 + 12 n + 1

2:    300 n^3 + 450 n^2 + 160 n + 5

3:   840 n^4+1680 n^3+1030 n^2+190 n+3

4:  1260 n^5+3150 n^4+2730 n^3+945 n^2+107 n+1

5:  27720 n^6+83160 n^5+93030 n^4+47460 n^3+10689 n^2+819 n+5

I have an expression like; 0.7x + 5e-10y, which I would like to approximate to 0.7x.

Round won't work as it will also round the 0.7 down to zero.  I have tried using he Digits command, but it seems to only work half of the time.

Is there a simple command that can put a ceiling on a number like e-5, so that any number lower than that will not be returned?

Cheers;

Robert Ward