Im attempting some very basic calculations where numbers are stored in variables with correct units. However i wish to take a variable to the power 2 without altering it's unit. This is a really easy but strange calculation to make which is why i guess Maple is having trouble with it. 

e.g. I have a variable A with a number 4 stored inside with unit in Meters. I want to take A² = 16 meters and and not A² = 16 meters². 

Is there a function or way to select the base number without having to write an entire line about it? 

convert(A,'unit_free')^(2)*Unit('m')

can do the trick but i believe there has to be an easier, less complicated, way to achieve this? 

Hello everybody,

In the linearised theory of gravity, I want to do some symbolic calculations.  First, I need to set that:

Then I want to see how the Christoffel symbols will change by putting the above in this:

Any hint someone?  I really appreciate the help for learning the Physics package.  Thank you in advance.

Mario

Error, More than two dependent variables, please indicate the desired scene

Hi everybody, 

I am working with Maple 2015.2 ; system = OS X El Capitan
I would like to compare the outputs of two files by using  the Worksheet:-Comparator command

OriginalFile.mw file contains this single instruction
> a:=1;

ModifiedFile.mw contains this single instruction
> a := 2;

Both us are located on my desktop, which is also my current directory in the worksheet from which I am going to run the comparison.

MyDir := cat(currentdir(), "/Desktop/");
OriginalFile := cat(MyDir, "OriginalFile.mw"):
ModifiedFile := cat(MyDir, "ModifiedFile.mw"):

# to verify that all is going well I use these two commands 
# Worksheet:-DisplayFile(OriginalFile):
# Worksheet:-DisplayFile(ModifiedFile):

Running the  command  Worksheet:-Comparator(OriginalFile, ModifiedFile) returns me error messages :
The first one is  (after having selected  "compare" and next "run" in the Comparator Maplet) 

and the second one (after having cliked ont the "OK" button" on this alert window)

Note that the same thing happens if I use Worksheet:-Comparator() and select the two files with the browsers
Could you please help me to understand what happens ?

Thanks in advance

How do I solve the problem that attached? Please give me the correction. thank you

Greetings!

Strange things happen with the "Explore" command! Let's say I want to plot the function F(x)= a*x. When I am writing:

>Explore(plot(a*x,x=0..10),parameters=[a=0..2]) ;

everything is OK, but when I use:

>F:=a*x;
>Explore(plot(F,x=0..10),parameters=[a=0..2]) ;

the initial frame is correct but when I try to move the parameter cursor, the plot dissapears. 

Any ideas what is wrong and how I can fix this?

Hi everybody,
 

I write a worksheet which contains thesimple code provided in ?Maplets[Button] :

with(Maplets[Elements]):
maplet := Maplet(["Select one:", ......]) 
Maplets[Display](maplet):

As mentioned in ?MapleViewer it is possible to export a worksheet in a .maplet file (I use Windows 7) and to execute it by double clicking on the corresponding icon.
I proceeded as explained in the help page
But double clicking does not work with me : a "User Interface Customization System" window opens and shuts after a few seconds without displaying the expected maplet 

(right click + open with and select mapleviewer.exe shows that mapleviewer.exe does exist, so the issue does not likely come from an incomplete Maple installation).

I tried a few variants of the worksheet, such that
with(Maplets[Elements]):
Maplets[Display](Maplet(["Select one:", ......])  ):
or even
Maplets[Display](Maplet(["Select one:", ......])  ):

But it keeps getting bad
Could you please help me to fix this ?

TIA

Dear 

Hope you will be fine. My file takes to much time to solve the system of nonlinear algebraic equations for Iterations=8. please solve my problem I will be waiting for positive response.

Error_graph.mw

I'd like ot make a 3d graph that is log scaled on at least one of the axis. So far I haven't found a way of doing this that gives a graph that I genuinely like.

The following worksheet shows two ways of making the graph- the first generates the lines on the surface in a very bunched way, the second typesets the tickmarks in a very ugly way.

How can I get a graph with well placed lines and nicely typeset tickmarks?

How do other people make 3d logplots?

Download logplot3d.mw

I am trying to solve the wave equation in polar coordinates.  The initial condition on u is given by f(r,theta) and the initial condition on u_t is zero.  The weight function is w(r).  I am not sure why it will not evaluate this as I know the solution remains finite on the domain (the unit disk).  Here is the code: 
 

Download Section_6.3.mw

Any assistance would be greatly appreciated. 

I have to generate a code for carrying out the matrix form of the revised simplex method. I have a code in place but am struggling to convert the constraints into canonical form and introduce the penalty function. If anyone has any ideas I'd be very grateful!

Best Regards

I have to prove the following:

So I do not need the explicit derivative of the function (r,t) . The metric is:

ds^2=(1-rg/r)*dt^2-(1-rg/r)^(-1)*dr^2

I am in the case of a collapsing star that emit radiation during the collapsing.  And I do not need to have a rotating black hole so that the reason I dont have dt*dr term in the metric, and I fix and .  So if you look in the Maple file attach to this post, I don't manage to obtain what I need to prove the equality between the two aspect of the same calculation.

Plese, take into account that I am sort of novice with the Physcis package and that the question is not part of an exam.

Thank you in advance for your help. 

Mario Lemelin

dAlembertian.mw

could you help with this? maybe because of too long exponents or just a maple bug?

when i try to solve this DAE it just crash. it says connection with kernel has been lost, and tells me to look for online help.

thank you very much...
 

Download crash_ecuation.mwcrash_ecuation.mw

Hi All.

I keep getting a incorrect plot of: plot3d(2*x/(x^2+y^2), x = -10 .. 10, y = -10 .. 10)

The negative range excursion is not appearing.

I have tried changing the domains and range settings but to no avail.

I have also tried placing brackets around the numerator and denominator but again to no avail. I also repeated the plot of earlier functions, on the same sheet, below the above function and had no problems with them. See the function below as an example of a good graph plot.

I noticed that the program flashes a negative value graph on screen and then only displays a positive result as shown above.

Good plot of: plot3d((-2*x^2+2*y^2)/(x^2+y^2)^2, x = -10 .. 10, y = -10 .. 10)

This example shows both the negative and positive f(x,y) values and surfaces.

Can anyone explain what is going on.

What I may be overlooking.

Is there a flaw in Maple 15?

I can get the correct graph using Microsoft Math which is a much less sophisticated program.

Omicron1

h1_y_h2.mw
 

im trying to build a matrix starting from a function, so i can later use this matrix to get a more simple function using linearfit from the statistics package, like a kind of regression.

i want to get a matrix starting from h__1(T1,T__1s) so it has to be a 3 columns matrix (T__1,T__1s,h__1). so as you can see, i have got the functions h__1 and h__2, but i need to evaluate it at differents values for T__1 and T__1s and building a kind of value-table in matrix form.

for h__1, T__1 must be higher than T__1s, or you could get imaginary values, don't know if that important for building the matrix.

thank you very much for your help.

Download h1_y_h2.mw