Hi

I need help to write a procedure that uses Maple`s built-in rand() - function to generate uniform random floating point numbers between -r and r, where r is an input parameter of the procedure.

>M:=600;

>R1:=rand(0..1):   R2:=() -> 2*R1()-1:       
>for i from 1 to M do
    f[i]:=R2()*rand()/10.^12:
  end do:

With this procedure I get random floating point numbers (+/-), but I can`t figure out how to generate numbers between +/- a parameter (in this case r).

If anyone could help me understand how to get this to work I would be very gratefull.

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?

I would like to plot a function u(r,theta,z) where r, theta, and z are standard cylindrical coordinates.  I would like u to be illustrate on the domain (say the unit cylinder) by a color scheme, say blue = minimum and red = maximum value of u.

Does anyone have any ideas how I could do this?

Heather

Hello, 

I loaded Maple to my friend's PC. But we can not execute any command in worksheet. When we write some lines and hit enter, it does not respond in anyway. (excluding simple calculations such as: 2+3 etc.) What is the problem and how can we solve it? 

PC: Windows 10 

Maple 2016.1

G := 6.6743*10^(-8);

a := 1.9501*10^24;

b := .3306;

c := 2.99792458*10^10;

d := 2.035;

pi := 3.143;

eps := 3.8220*10^35;

g(r) = 1-s(r)/0.06123;

j(r) = e^(-(1/2)*w(r))*(1-2*G*v(r)/(r*c^2))^.5

sys := diff(v(r), r) = 4*pi*r^2*eps/c^2, ics=v(0)=0

diff(u(r), r) = -G*(eps+u(r))*(v(r)+4*Pi*r^3*u(r)/c^2)/(c^2*(r^2-2*G*r*v(r)/c^2)),u(0)=1.3668*10^34

diff(w(r), r) = 1.485232054*10^(-28)*(v(r)+4.450600224*10^(-21)*pi*r^3*u(r))/(r^2-2*G*r*v(r)/c^2), conditions: w(0)=0,iterate it to find w(688240)=-2.05684, it solve must satistfy the both conditions.

diff(r^4*j(r)*(diff(g(r), r)), r)+4*r^3*g(r)*(diff(j(r), r)) = 0, conditions dg(r)/dr =0  at r=0, g(688240) =0.87214

diff(J(r), r) = (8*pi*(1/3))*(eps/c^2+u(r)/c^2)*(g(r)*j(r).(r^4))/(1-2*G*v(r)/(r*c^2)) condition J(0)=0.

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

How do I solve a differential equation in maple? Is there a specific identity that you can use?

I can't make maple solve this equation, any help please

Hello all, 

A question concerning NetCdf files was asked in 2012 and is still unanswered today.
Browsing the questions only returns this item, suggesting the NetCdf topic is not a concern in the Maple community.
Nevertheless, does it exist some capabilities in reading and writting NetCDF files ?
If not, are there some planned development on the subject ?

Let's hope now for not having to wait four years for an answer, all responses will be greatly appreciated, even negative.

years

PS : NetCdf capabilities already exist in Sage or Mathematica

hi 

With Maple2016 this fonction do not work right

searchtext("é", "BCU4isotherm302kselfheatingp1418075r1140479981mercredi16décembre20150900")

also and more important for me

if i use a readdata(name_file, [string]) it will read

[ "BCU4isotherm302kp3171389r1140479956mardi8d�cembre20150029"]

instead of  "BCU4isotherm302kp3171389r1140479956mardi8décembre20150029"

i have already try to put français as language in the option without any change. with(StringTools) do not helps

this problem was solved for maple15

best regards

Laurent

Hi.

I´m making a work sheet where I use the VectorCalculus package to evaluate surface of a plane.

When I try to evaluate a regular tripple integral after loading the VectorCalculus package I get the following error:

Error, (in VectorCalculus:-int) the domain must be an equation with a list of names on the left hand side

If I use the task menu to remove the package it works just fine, however I want it all as executable syntax within my worksheet so I tried "unwith(VectorCalculus)" but the package wont be removed by using this command.

How can I go about solving this issue?

https://i.gyazo.com/0f56ebe62bc54c7db303ab2ae05a601c.png

Hi! 

Tried to solve the PDE below (q and p are time-dependent variabels, q(t),p(t)):

pde := diff(rho(t, q, p), t) = -(diff(rho(t, q, p), q))*p+(diff(rho(t, q, p), p))*(2*q+2);
          

pdsolve(pde, rho(t, q, p));
           

And got the answer: 

rho(t, q, p) = _F1(p^2+2*q^2+4*q, -(1/2)*sqrt(2)*arctan((q+1)*sqrt(2)*(1/sqrt(p^2)))+t)

But I'm not sure how to interpret the result. I understand that  _F1 is an arbitrary function, but then I get confused with the comma? I thought that I'd get a function of q and p, where they depend on t. 

Best regards
Sannis

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

Hello all,

I have a question regarding printing to PDF. I am using Maple 2016.1 on Mac OS Sierra. When I choose print and use "Open PDF in Preview", I get to see something like this:

As you can see, the fonts are ugly and not anti-aliased at all (and it makes no difference whether I select that option explicitly in Maple preferences or not).
I've also tried Maple 2015, and it gives the same ugly result.

As a comparison, here is an example of a similar print of the same document that I've made in 2015:

Here, the font looks much better, properly aliased this time.
I also get this result when using Maple 18 on Sierra.

I am wondering: do other people also get this ugly result? In that case, it could indicate an issue with Maple 201X and Mac OS Sierra. Unfortunately, I no longer have Mac OS X El Capitan to compare...

P.s.: If someone wishes to try: just create some text input, choose Print, Open PDF in Preview, and then zoom in on the document.

Many thanks for your reply.

Regards,

Franky