## how i can reduce the runtime of the program ?...

hi..how i can rewrite section of this code as another form i,e ''for section''

I have a lot of line as this and runnig cise is time consuming.

is there another way to write this section in order to the runtime of the program is reduced??

thanks

 > restart;
 > with(LinearAlgebra):
 > with(VectorCalculus):
 > #Digits:=5: k:=6:
 > l:=0:
 > h:=1:
 > m:=4:
 > n:=4:
 > l1:=2*h:
 > l2:=2*h:
 > N:=0.5:
 > nu:=.3:
 > E_m:=70e9:
 > E_c:=380e9:
 > rho_m:=2702:
 > rho_c:=3800:
 > lambda_m:=nu*E_m/((1+nu)*(1-2*nu)):
 > lambda_c:=nu*E_c/((1+nu)*(1-2*nu)):
 > mu_m:=E_m/(2*(1+nu)):
 > mu_c:=E_c/(2*(1+nu)):
 > with(orthopoly):
 > for i from 0 to 5 do: L(i):=sqrt((2*i+1)/2)*P(i,z): end do:
 > Z:=rho_m+(rho_c-rho_m)*((1/2)+(z/h))^N;
 (1)
 > U:=lambda_m+(lambda_c-lambda_m)*((1/2)+(z/h))^N;
 (2)
 > S:=mu_m+(mu_c-mu_m)*((1/2)+(z/h))^N;
 (3)
 > d:=Matrix([[0,0,0,0,0,0,0,0],[sqrt(3),0,0,0,0,0,0,0],[0,sqrt(15),0,0,0,0,0,0],[sqrt(7),0,sqrt(35),0,0,0,0,0],[0,sqrt(27),0,sqrt(63),0,0,0,0],[sqrt(11),0,sqrt(55),0,sqrt(99),0,0,0],[0,sqrt(39),0,sqrt(91),0,sqrt(143),0,0],[sqrt(15),0,sqrt(75),0,sqrt(135),0,sqrt(195),0]]);
 (4)
 >

 >
 (5)

## how I can dsolve this differential equation...

hi...

how I can dsolve this differential equations. parameter p is unkown.

I want to gain w(x) and u(x) and psi(x) and p.

thanks

 >
 (1)
 >
 (2)
 >
 (3)
 >
 >
 > with(PDEtools, casesplit, declare);
 (4)
 >

## how i can dsolve this differential equations........

hi...

how i can dsolve this differential equations and obtain w(x) and U(x) and phi(x) analytical or numerically?

thanks

 (1)

 (2)

 (3)

## How can I convert a result to a trigonometric iden...

How can I convert the result (2) to equal to the trigonometric identity (kw/s^2)*tanh(a*s/2)?

 >
 (1)
 >
 (2)
 >

## Books free of maple

Maple 2017

Books free. Like!!!

Lenin Araujo Castillo

## How should I save a procedure and read it into a ...

I have a module with quite a few procedures and it is getting too long and complex. Basicially I write each procedure in a seperate document, them copy and paste it into the module. I want to improve matters as save each proc and read it in to the module

e.g.  Qdim:=proc(A,B).........end proc

save Qdim , "Qdim.?"   have tried .txt ,.mla , .m  They save fine.

in the module have tried

read "Qdim.txt" etc.   I have included Qdim in export but Qdim doesnt work Qdim(A,B) returns Qdim(A,B)

which procuces an error

Error, (in unknown) could not open C:UsersRonanDocumentsMAPLERational TrinonometryQdim.m for reading

## prime notation setup changed in Maple 2017...

Not sure if this is documented explicitly to Maple users, but normally (prior to Maple 2017) interface(typesetting=extended) was all that was required to output display diff(y(x),x) as y'(x)

With Maple 2017 typesetting=extended is default and one must use with(Typesetting)  Settings(typesetprime=true) in order to output the display of diff(y(x),x) as y'(x).

Perhaps this is well documented somewhere, however I was unable to find the change.

## make latex() generate y'(x) for diff(y(x),x) ?...

I know the latex() command in Maple have many issues and I have no hope of what I will ask having a solution, but thought to ask any way.

Is there a way to make maple generate the latex for all the derivatives to use ' instead of d/dx ?

for example, given this

ode:=diff(y(x),x)=x;
latex(ode,output=string);


The Latex generated (which is correct) is

{\frac {\rm d}{{\rm d}x}}y \left( x \right) =x

but sometines I find it more readable if the latex was

y'(x)=x

which is more common in textbooks and other places. The problem also is that I am using worksheet so can't use  y'(x) as input.

But even switching to document mode, and writing it 2D math as input, the Latex output still does not match the input

So if there is a solution to this, would it require changing the latex() command itself? or can it be done at user level?

I'd like all orders of derivatives anywhere in the equation to come out as y'' etc.. so diff(y(x),x\$3) should generate the latex y'''(x) and so on.

Is there a trick to do this?

Maple 2017.2

## Changing coordinates for matrix plot...

I'm plotting matrices using the proc in the attached file.

How do I move the rows in the plot closer to each other?
The first picture show the rows plotted in the values [13,14...19].
I want them to be plotted in values like [13,13.5,14,14.5...].

Second picture shows how I would like it to be. Created it in paint, from a different matrix.Matrix_plot.mw

hi..

I dont know why ''Y'' in this code does not calculate?

Also in Determinant  should exist term ''Omega''!!!

however this term not apear!!

thanksZrO2.mw

 >
 > with(LinearAlgebra):
 > with(LinearAlgebra):
 > with(VectorCalculus):
 > E_c:=200e9:
 > rho_m:=2702:
 > rho_c:=5700:h:=1:Digits:=200:

## "unable to convert to an explicit first-order syst...

hi... I have a problem with dsolve.

"unable to convert to an explicit first-order system"

thanks

## Wrong result in symbolic integration...

The following integral is obviously positive, but Maple returns 0:  (Maple 2017)

assume(gamma1>0, gamma2>0 , mu1, 'real', mu2, 'real')'
int( 1/sqrt( Pi^2 * gamma1 * gamma2 * (1+((x-mu1)/gamma1)^2) * (1+((x-mu2)/gamma2)^2) ), x=-infinity..infinity )
0

(This is the Bhattacharyya coefficient between two cauchy distributions). Numerical integration works.

## Issue with PDEtools:-Solve...

I have a complicated set of first-order differential equations, which Maple seems capable of solving. So far so good. The obtained solution is fed into another complicated set of first-order differential equations, which, again, Maple seems capable of solving.

But this final (combined) solution cannot possibly be the complete one as it does not contain a specific (sub)solution which DOES satisfy both sets of equations (checked in Maple by evaluating these equations for that specific solution). And there is no warning raised concerning any solutions that may have been lost.

The problem seems to be that the integrational constants associated with solving (in turn) the two sets of equations become messed up together, or erroneously 'reused', in some mysterious way. For if I rename the integration constants of the first solution before feeding it into the second set of equations, then this specific subsolution IS contained in the final solution.

Therefore the following questions:

1.) Could there possibly be some erroneous 'reuse' of integration constants going on? It seems to me that in solving the second set of equations, PDEtools:-Solve would have to make sure that it numbers any new integration constants in such a way that there would be no conflict with the ones obtained in solving the first set of equations.

2.) Is there some (global) variable that determines what letter is assigned for the integration constants? I could use any such to easily switch names between the first and second solving.

PS: I think, it makes little sense to upload any code/worksheet here.

## Why does maple rewrite my definition, and does it ...

Hello

I am trying to plot a harmonic oscillation, but maple keeps rewriting my defintion so when I plot, it gives me a wrong graph...

How do I stop it from doing this, I am assuming it is this that causes the problem, and not the plot command?

Here is what I get:

And here is what I want - made with geogebra.

If it isn't the definition that is the problem, what plot command should I be using then?

With gratitude
Toby

## Diff. Equation with boundary...

Hey. I have the following Diff. Equation:

diffeq := diff(y(t),t,t,t,t)+10*diff(y(t),t,t)+169*y(t)=0

and I have the conditions y(0) = 0, y'(0) = 1, and y(t) -> 0 for t -> infinity

I know how to do with the first two conditions, but how do you do it with a boundary? I've read the posts made earlier on here, but I can't seem to figure it out. I've tried:

dsolve({diffeq,y(0)=0,D(y)(0)=1,D(y)(infinity)=0},y(t))

Returns nothing.

Any help would be appreciated.

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