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I dont understand what's the 'label' thing in the answer here.

 

Thanks.

 

casper

Suppose I want a random sample of 500 numbers

RandomSample(Normal(0,1)),500);

Good, now if I am understanding properly [0,1) means positive values with a mean of 0 and standard deviation of 1.  However in Maple RandomSample(Normal[0,1)),500); is not allowed due to bracket mismatching. 

how do I get the RandomSample domain [0,1)?

Hi all I've a program running that has been stopped with the error Execution stopped: Stack limit reached. at that time the program was using memory used=480073.6MB, alloc=594.8MB, time=16330.02 The host computer has 16 CPUs and 50Gb of Ram, so I don't think the problem is the memory... Any hints? Thanks Salvo ps: I've found an old discussion about this problem, but it was very old (2005, M9) so I've thought I could open a this one.

I'm new to programming.

I don't understand what I'm doing wrong in this

If anyone could help me with this, I'd very much appreciate it.

See the attached picture called "equation". That is the differential equation I'm trying to solve. The graph (for m=1) should like as it does in the other attached picture called "graph".

I tried this

----------------------

with(DETools):
m := 1;

de := diff(y(x), x, x, x)+((m+1)*(1/2))*y(x)*(diff(y(x), x, x))+m*(1-(diff(y(x), x))^2) = 0;

DEplot(de, y(x), x = 0 .. 8, [[y(0) = 0, (D(y))(0) = 0, (D(y))(infinity) = 1]], y = 0 .. 1);

---------------

But goes this error message

Error, (in DEtools/DEplot/CheckInitial) initial point in all initial conditions must be the same

I don't know how to get around this because my initial conditions are what they are, I can't change them.

Does anyone know of a way to fix this or know of a better way? The reason I need this is because I need to get the graph for m=0.77, which isn't in those photos.

 Any help is appreciated.

 

 

Im  writing a loop which starts by solving a circle equation,  how do i instruct maple to follow another another set of instruction if no real roots are found?

im looking to do something like this

(x1a, x1b) := fsolve((x-h)^2+(eq2-k)^2-r^2)

if real roots are found, do this

else, do something else

end if

I hope im clear enough on what im asking. If not, please let me know.

thanks

Lovinash

Hello

I have a matrix, let's call it A. I want to define a new matrix by taking every n-th row in the A matrix. How do i do that?

For example,

A= | 2 3 5 |
     | 9 2 1 |
     | 5 1 2 |
     | 1 8 9 |

 

the B, if n=2, is equal to

| 2 3 5 |
| 5 1 2 |

I'm trying to model Conway's game of Life and I keep running into the same error mesage. I've narrowed the problem down to this line of code

S0 := [[0,0,0,0],[0,1,1,0],[0,1,1,0],[0,0,0,0]];
n:=4
X:= Array(0..n-1,0..n-1,S0)
Error, bad index into Array

I don't know what this error message is or why I'm getting it, any help would be appreaciated.

Hi, sorry to post this as I have read past topics about roots but havent really understoond much.

I have an equation that gives 8 roots. some of them can be real and some can be imaginary. how do i list them separately? I attach the worksheet...

 

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Hi to all

I want know that can we slove the following equation

=0

where

F(l)= coth(l*(S0)))/coth(l*(S0-1)));

Is this possible from mathematical point of view?

 It make any sense to slove the above equation?

 

I have been trying to do this for some while now but am not having much luck.

Basically what I need is a hermitian matrix, with real values on the diagonals X~N(0,1) and complex values on the off diagonals X~N(0,1/2)+i*N(0,1/2)

Obviously as its hermitian I need Xij = Xji*
 

I have tried a few things but can't get anything to work correctly, in my latest attempt I decided to try and construct the 2x2 case from scratch using if and for loops;

for i to n do

for j to n do

if i <> j then

restart; with(DEtools); phaseportrait([(D(x))(t) = -.1+x(t)^2-x(t)*y(t), (D(y))(t) = y(t)^2-x(t)^2-1], [x(t), y(t)], t = -10 .. 10, [[x(0) = 0, y(0) = 1], [x(-2) = -2, y(-2) = -1], [x(0) = 1, y(0) = 0], [x(0) = 0, y(0) = 0]], stepsize = 0.5e-2, scene = [x(t), y(t)], linecolor = t, x = -4 .. 4, y = -3 .. 3) I want to explicitly draw the hyperbola with arrows in the direction of the vector field. How do I obtain this? With the initial conditions I get solution curves that I dont want.

# Hello!
# I've been trying to replace one expression into another, which includes the derivative of a quotient, but algsubs doesn't work and I don't know why.
# To make it simple, I want to replace a expression from rho into the expression for q_x. Let's say rho is a function of alpha.
>
> restart;
> alias(rho = rho(x, y, t)); alias(rho_an = rho_an(x, y, t));
> alias(p = p(x, y, t));
> alias(q_x = q_x(x, y, t));
> alias(alpha = alpha(x, y, t));
>
>
> rho_an := alpha;

Can someone help me please? I cant find what is wrong. thank

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Nash

In the book Introduction to Maple by Andre Heck books.google.co.uk/books  the author manage to plot the canadian flag
in maple by using the following code:
 

restart:
with(plots):
with(plottools):

X := proc (cc) local S, R, mapleleaf, rectangles, border:

S := proc (t) options operator, arrow; 100/(100+(t-(1/2)*Pi)^8) end proc:
R := proc (t) options operator, arrow; S(t)*(2-sin(7*t)-(1/2)*cos(30*t)) end proc:
mapleleaf := plot([R, proc (t) options operator, arrow; t end proc, -(1/2)*Pi .. (3/2)*Pi], coords = polar, axes = none, color = cc, numpoints = 1000):
mapleleaf := subs(CURVES = POLYGONS, mapleleaf):
rectangles := rectangle([-5, -1], [-3, 4], color = cc), rectangle([3, -1], [5, 4], color = cc); border := plot({-1, 4}, -3 .. 3, color = black):

display([mapleleaf, rectangles, border], view = [-5 .. 5, -1 .. 4]) ;

end proc:

Ap := Array(1 .. 2, 1 .. 2):   

Ap[1, 1] := X(red):         Ap[1, 2] := X(blue):    
Ap[2, 1] := X("green"):    Ap[2, 2] := X("Orchid"):

display(Ap);