hello , to solve a differential euqations , maple gave me this error. please help me.

TG.mw

I use maple worksheet to organize a derivation, etc.

But most of the paragraphs and subparagraphs should normally be closed.

But after executing the file (using !!!) every paragraph is opened.   

We need better ability to control the opening/closing of paragraphs.

How do I close ALL paragraphs.

Also, how do I close all TOP level paragraphs (but not subparagraphs).

Thanks, Chee

Hi all,

I'm trying to initialize a 4-vector and promote it as a tensor in Maple 16 using the Physics package. My attempt so far has been unsuccessful :) 

This 4-vector needs to be a function of the coordinates X. What I'm trying to do is to allocate terms by terms my tensor as indicated in my attempt below. Everything looks fine (the query is telling me F2 is a tensor) but when I'm trying to compute contravariant quantities, I can't obtain an answer for a given coordinate (here F2[~n](X) is not equal du v_1(X))... Finally, the last line, computing the sum over all the indexes is not giving me an answer... 

restart; with(Physics):
Setup(mathematicalnotation=true):
Setup(coordinatesystems = cartesian):
Define();
g_[]:

F2[1]:=(x,y,z,t)->v_1(X);F2[2]:=(x,y,z,t)->v_2(X);F2[3]:=(x,y,z,t)->v_3(X);F2[4]:=(x,y,z,t)->1;

Define(F2[mu](X));

Define(F2,query);

F2[1](X);F2[2](X);

F2[~1](X);F2[~2](X);

F2[~nu].F2[nu]

Surely, something is wrong in my way of defining a spacetime tensor. What would be the solution to obtain a decent contravariant F2?

Another more or less related question would be to know how to compute a taylor expansion of a function itself i.e. 1/(1+f(X))~ 1-f(X) since f<<1? Would there be a built-in fonction to do such a thing?

Many thanks!

Vincent

Hello people in mapleprimes,

I hope you will give an answer to my following question.

This is a question of nonunit(algebraic) in patmatch.

In help page of maple this examples are on.

Case i)

>patmatch(a, A::(nonunit(algebraic))+B::(nonunit(algebraic)), 'la');

false

Case ii)

>patmatch(a,A::(nonunit(algebraic))+B::algebraic,'la'); la

ture

[A=a,B=0]

Is unit in the case of sum zero, so that in Case i) false is shown, though in Case ii) B=0 is returned?

Best wishes.

taro

Hello, 

I`m new with the Physics package. I have a Hamiltonian in a lattice written in terms of creation and annihilation operators. The Question is, How can I label a Creation and an Annihiliation operator for each site in the Lattice. WIth this, I can compute mean values and other stuffs associated with the Hamiltonian.

Many thanks in advance

Dear people in mapleprimes,

>define(INT, linear, conditional(INT(a::algebraic, X::name) = a*X, _type(a, freeof(X))), INT(X::name, X::name) = (1/2)*X^2);

>INT(2*x+4, x);

x^2 + 4*x

>INT(z+x, z);

(1/2)* z ^2+ x*z

is written in the help page of maple.

This code is to make a function INT.

What it means is that if INT(a::algebraic, x::name) then this is transformed into a*X, where a is independent from x.

And, INT(X::name,X::name) is transformed into (1/2)*X^2.

The first of what I want to ask you is the way of use of "_type", which is not in the help page, and as for names with "_" ahead, 

it is written that "_" means internal command for Maple, so not to use it. Is it right to use a name with "_" ahead of it here?

The second of what I want to know is the way to use "conditional."

Please teach me the meaning of this.

Thanks in advance.

I hope you will teach me the above questions.

Best wishes.

taro

Hello guys

I have a linear differentional equation which is in the 4th order. It is shown in the below:

P:=phi(x):
eq:=a11*diff(p,x,x,x,x)+a22*diff(p,x,x)+a33*p:
eq:=0:
where a11 and a22 and a33 are constant coefficients. The boundary value for this equation is:

phi(a)=sigma1 , phi(-a)=sigma1 , diff(p,x)(a)=0 , diff(p,x)=0

Now consider :

a11:=2.731e-10:
a22:=-1.651e-9:
a33:=3.09027e-10:
a:=35.714:
sigma1:=200e6:

when I use dsolve for deriving a good answer in this equation. there are four real roots .How can I solve it with these boundary condition?

I need to extract phi(x) from this equation.

Thanks

seq(i,i=1..5);  gives output 1,2,3,4,5

seq(i,i=5..1);  seems to get ignored in Maple 7.  It does not return an error message.

I was hoping to step back from a large number to a smaller one in stepsof minus one.  The for loop structure allows negative "increments" - so I experimented by putting the decrement value of -1 between the two dots.  I was expecting it to givean error message, so was surprisd when it gavesome output!

eg  seq(i, i=5.-1.2);  gives output of 38, -1

I'm curious as to what is happening here?  Also, has the seq command been upgraded in later versions of Maple?  eg is it possible to do negative decrements?

I have to find the volume of a solid using the disk/washer method and the shell method.  I think I have the first part(disk/washer) right.   I think the shell is off. The problem is "the region in the first quadrant that is bounded above by the curve y = 1/x^1/4, on the left by the line x = 1/16, and below bythe line y = 1 is revolved about the x-axis to generate a solid."    I am having computer problems so any help is appreciated. Thanks

Consider a plot generaged by:

export_plot_options:=font=[TIMES, roman, 30], axis=[thickness=4, location=low], size=[850,850]:
points := [seq([seq(exp(-(x^2+y^2)*(1/100)), x = -10.0 .. 10.0)], y = -10.0 .. 10.0)]:
plots:-listdensityplot(points, export_plot_options);

How can one get rid of white space between the axes and the actual data??

thanks

Hi there,

I would like to know whether there is some way to print non-integer axis numbers for a given plot.

Let's say I have an array for an independent variable such as [0.5 1 1.5 2]. I would like Maple to use these values in the corresponding axis instead of printing the array indices [1, 2, 3, 4].

I would like to know how this is done for a surface plot.

Attached is the worksheet where "b" is such a parameter/independent variable: MapleSimulation_test11.mw

Thank you,

jon

I am just starting with Maple 18 on Windows 8.1. I did not like the default color palette for 2D graphs and tried another one. So I edited my maple.ini file, which was in 

Hi,

  Excuse me, I tried to substract in a series expansion. It works for Taylor-type expansion, but not Laurent-type ones

*********

ffff:=1/(t-3);
ggg:=taylor(ffff,t=infinity,3);
coeff(ggg,t,-1);

ffff:=exp(t);
ggg:=taylor(ffff,t=0,3);
coeff(ggg,t,1);

*********

Maple gives me

Error, unable to compute coeff

1

. My question is, why "coeff" does not work in the first case? how to make it work? Though I can copy the expansion part, assign it to another variable, and "coeff" will work

Excuse me,

  I have the following input

***

fff:=x1^k;
int(fff,x1=0..x2);

***

I would like to obtain

1/(k+1)* (x2^(k+1)), k<>-1

but maple gives me just the same integral. Is there any way to get the expression?

Thank you!

Hello,

Im solving 4 ODE equations with BC. im trying to shoot the initial value but im having this error:

""Error, (in isolate) cannot isolate for a function when it appears with different arguments""

anyone could help me???

shooting92.mw

Download shooting92.mw