I have been computing curvature etc of a four-dimensional metric that invloves three arbitary functions using the DifferentialGeometry package. I am now intereted in whether Maple can compute the Killing vectors. I have used the code of Example 3 from the Maple help page on KillingVectors in the  Tensor subpackage of the package DifferentialGeoemtry. If I set the arbitrary functions to be constants using the' auxiliaryequations' part of the code, then Maple outputs Killing vectors, so all good so far. If I leave the three arbitary functions to be arbitrary, however, specifying only that they be nonzero (as in Example 3) Maple had not produced any output after five hours, though when I moved the cursor over the tool bars at the top of the screen it turned to an hour glass, indicating that Maple was busy. Does anyone have experience with whether I am asking too much of Maple or whether I just need to give it more time to produce answers? If the latter, how long? The Example 3 indicates Maple will consider several possibilties including the completely arbitrary option, though that example only involves one arbitary function, so having multiple arbitary functions obviously increases the complexity.

Hi, how can you compute the normal distribution value (in my case the standard normal distribution) of a value and likewise the inverse normal distribution for a given random number in Maple?

I haven't really found any way to do this easily like you can in e.g. Excel or Matlab.

For example if I have a value z = 2.7102, I can in Matlab find the standard normal distribution value as:

Φ(z) = cdf('normal',z,0,1) and inversely z = norminv(Φ(z) ,0,1)

Or in Excel: Φ(z) = normdist(z,0,1) and z = norminv(Φ(z) ,0,1)

How to do this in Maple?

Using the definition of a derivative as a limit i.e., lim h->0  f(x+h)-f(x)/h  .Find the derivative of the following functions:

a) f(x)=3x^3-2x^2+5x-7

how do i solve and type in maple? please help

Hello,

I’m a uni student at the moment. I just could not get the answer right. Here’s the equation. 

(-69/50)*sin((32/25)*x)=(4/5)*exp((-23/50)*x)

Find the smallest positive solution and correct to 10 significant figures. 

Looking forward to to the answers. 

Thank you!

Maple 2015

Suppose you want to plot x = Rcos(omega*t) for t = 0..4Pi/omega.

Below is the sketch of the function.  Is there a way to plot the functions using Maple's plotting syntax?

plot(R*cos(omega*t), t = 0 .. 4*Pi/omega);
Error, (in plot) expecting a real constant as range endpoint but received 4*Pi/omega
Thanks

I googled, read help and not able to find how to do this. 

I want to change the zoom in worksheet to any value I want, and not just 100%,150%,75%, etc.... which are the values that are listed in View->Zoom factor.

Is there a place one can type in the zoom value they want? Say 110% or any other number?

windows 10.

Thank you

Hi all,

For what its worth,
I want to make a graph of data.
Attached is file to show how far I got.

multiplication_table_list_to_graph.mw

multiplication_table_list_to_graph.pdf

Regards,
Matthew
 

Hello everyone,
Gretting from me. I am Md. Abubakar Siddik from Bangladesh.

I have 20 equations  and 20 variables for a system. I want to solve it numerically. 

Any advice ?
system_equation.mw

Thank you in advance for your cooperation. I look forward to hearing from you.

I read a string from file which contains a sequence of Maple commands, all in one string. The commands are separated by ";" in the string. I need to then evaluate all the commands in the string as if I typed them one after the other. 

Here is an example

data:="x:='x';y:='y';sol:=dsolve(diff(y(x),x)=1,y(x));"; #read from database
parse(data);

Warning, extra characters at end of parsed string
x := 'x'
 

I want the result to parse to be as if I typed

x:='x'; 
y:='y'; 
sol:=dsolve(diff(y(x),x)=1,y(x));

I looked at help in parse page, but I do not see what I need to do. It says that 

If the option 'statement' is specified, the string must consist of exactly one Maple statement (which includes expressions). The statement is parsed and evaluated, and the result is returned.
 

But I am not using the statment option. I also tried using this option, no change, same problem.

Is there a way to prase such a string? 

Thanks

  SALUT,

J'ai exécuté la procédure suivante, afin de tracer une courbe (Bézier), mon objectif final est de construire "à l'aide de Maple" une théière (avec des révolutions et des rotations certainement), y at-il des suggestions?

The conditional trigger in the code below does not cause a halt although odeplot shows x dipping to a value below 2.

What is the correct coding of this event to cause a halt when x becomes less than 2?

Does any Maple documentation show examples of working discrete events with conditional triggers?

restart;

DE1 := diff(x(t), t, t) = -x(t)-(diff(x(t), t))+y(t);

DE2 := diff(y(t), t, t) = y(t)-(diff(y(t), t))+x(t);

ICs := x(0) = 2, (D(x))(0) = 1, y(0) = 0, (D(y))(0) = 1;

sol1 := dsolve({DE1, DE2, ICs}, {x(t), y(t)}, numeric, event_initial = true, events = [[[0, x(t) < 2], halt]]);

plots:-odeplot(sol1, [t, x(t)], t = 0 .. 3);
 

In the following case evalhf Int not working. Please help

evalhf.mw

Hi, 

In two lines below Command1 and Command2 have the same value

Command1 := subs([a=1, b=2], a*x+b);
Command2 := eval(a*x+b, [a=1, b=2]);

Are there pros and cons of using one over the other?

Thanks in advance

diff(m(t, x), t)+diff((u(t, x)^2-(diff(u(t, x), x))^2)*m(t, x), x) = 0

How I can change it by using this transform

m(t,x)=u(t,x)-diff(u(t, x), x,x)

to get a new PDE only with u(t,x)

then I need to change u(t,x) by

u(t,x)=u(y)

where y=x−at

How I can do this in Maple?

Hello everyone!

I am struggling to figure out the cause of the problem with Explore command. To put it as simple as possible:

 a := <3, 4, 5>

Explore(a[i], i = 1 .. 3);
Error, (in Explore) bad index into Vector

I am pretty sure that this has to do with an attempt to evaluate A[i] with i not yet defined, but why does Explore behave this way? seq has no such problem:

seq(a[i], i = 1 .. 3);
3, 4, 5

But as soon as I put it into Explore, seq seems to forget all its "special evaluation rules":

Explore(seq(a[i], i = 1 .. 3), b = 1 .. 2);
Error, (in Explore) bad index into Vector

It is probably for the same reason that I can't solve the problem with unevaluation quotes such as: 

Explore('a[i]', i = 1 .. 3);
Error, (in Explore) bad index into Vector
 

What am I doing wrong??