hi..

is correct this answer for differential equations??

i think order of result should be in (10^6 or 10^9 or higher) range....

please check it

thanks

hpp.mw
 

Download hpp.mw

I have a data point set:

x_val:=<250,300,350,397,451,497,547,593,647,691,745,788,840,897>:
y_val:=<0,0.5,2,6.3,23.2,48.7,71.2,83.4,90.1,92.8,94.7,95.7,96.9,97.8>:

I want to make a least square fit using this difficult function:
 

function:=x->1-exp(-(k*exp(-(E/(8.314*873.15))*((873.15/x)-1)))*(0.026/350))

but both Statistics[Fit]:
 

with(Statistics):fit_nelog:=Fit(1-exp(-(k*exp(-(E/(8.314*873.15))*((873.15/x)-1)))*(0.026/350)),<x_val|y_val>,x,parameternames=[k,E],output=[parametervector,residualsumofsquares]);

and DirectSearch[DataFit]:

with(DirectSearch):fit_nelog2:=DataFit(1-exp(-(k*exp(-(E/(8.314*873.15))*((873.15/x)-1)))*(0.026/350)),x_val,y_val,x,method=cdos);

give wrong k,E parameters. The correct parameter values were obtained with Excel Solver:

k=27843.3551042397

E=68.4

The approximately correct parameters were fitted when using logarithm form of the function.
How can I obtain correct parameter values in Maple using given form of the function?

Hello people in mapleprimes,
I have a question.
I appended two pictures where from the same code, two different orders of
expression appear.
How can I do for this so as not to get error messages?
The cause of this is simplify(%,symbolic) brings different order of term a__0^(-k)*F__D ahead of a parenthesis in a jpg.file and F__D*a__0^(-k) after
that parenthesis in another jpg.fine both in the line above that of  "dairihensu1."

In this case, What I can do?
Please help me.
Best wishes.

taro

my_code.mw

Original code is

e7_4:=F__D*(Omega+1)*beta/(beta-1) = F__I*a__D^(-k)*a__0^k+T^((sigma-k-1)/(-1+sigma))*F__D*phi^(k/(-1+sigma))+F__D;

a1:=beta=k/(sigma-1);
subs_free:=
  proc(a,b,c)
    local b1;
    b1:=isolate(b,c);
    subs(b1,a);
  end proc;
isolate(e7_4,a__D^(-k));simplify(%,symbolic);dairihensu1:=subs_free(%,a1,sigma);e7_5:=applyop(simplify,[2,4,1,3,2],dairihensu1);

A case without error.

A case with a error.

Pressure_loss.mw

Hey all, could someone pls help me with how i can setup the equation for f in my worksheet. It should look like v and Rey with 45 data points. I've tried alot but i can't seem to solve it mysefl. Is it because i solve and map at the same time?

Thanks

i wrote this problem to solve 

Delta= Sum(j=1 to n)SUM(i=j to n)(pi*hj/Ad(t,ij)*Et,ij))

Where n=70,  G= ftj (t)/(4+0.85*t) , where (t =8, 16, 24,…….up to 8*n), hj= 13 for all j except j1 =18

Ad= (Aj+s(mij-1)), where Aj varies

Mij=ES/E(G),          where E(G)= 57sqrt(1000*G)

Download short.mw

Hello everyone,

I am trying to solve a system of ODE's numerically but the problem is with the condition f(0)+g(0)=1.

Here is the system with the initial conditions,

restart:
ode1:=diff(f(x), x,x)+(f(x)+g(x))*diff(f(x),x)=0;
ode2:=diff(g(x), x,x)+(f(x)+g(x))*diff(g(x),x)=0;
ics:=f(0)+g(0)=1,D(f)(0) =0,D(g)(0) =1;
dsolve({ode1,ode2,ics},numeric);

which give an error

Error, (in DEtools/convertsys) invalid specification of initial conditions

The above system is a simplified form of a very complicated one.

Hi

I have a maple file (saved as a workbook) which is saved in dropbox and has been saved during progress.  However, when I open the last version in maple, it opens a version which looks like it is some of the first versions. I have tried following things without success:

* Restore previous versions from dropbox and open them in maple.  No matter which version I open, it shows the same two lines of text.  In dropbox I can see all previous versions and their file size which all are different and increasing in size over time as more was added to the file.

* send the file to another computer and open in maple on that computer

Does anybody have the answer to what I can do/what the problem is?

Thanks!

/Katie

I am writing a package to define a few Records and collect some quantities and formulae to do some arithmetic with.

At some point I started running into a severe problem: Each time I want to use one of the exports form the module, the Maple kernel dies with a "Stack limit exceeded" message. The issue is: This seems to happen only on Maple 2016. I had some issues in Maple 2015 but that got sorted by rewriting some stuff. I never had any issue like that with Maple 15. I went as far as commenting out most of my .mapleinit code to make sure that did not cause issues. The code works as intended in Maple 15 and in Maple 2015.

I am posting this here and am asking others to see if they can reproduce this. Needless to say I will SCR this. But I actually need to get this to work.

The error can be triggered by simply entering

Booster;

after loading the package. Needless to say, it should just echo the name "Booster", to get more one would need to enter eval(Booster) (due to the last-name evaluation rules).

Thanks,

M.D.

BooMBA.mw

For remainder of division of a (multivariable) polynomial to several polynomials at a same time one can use NormalForm in Maple. It is easy to write a procedure to also show the division but I wonder if there is any determined command such as NormalForm for this aim?

Hej all,

I have a problem. When i have a 9-1 vector "DD" how can i get maple to solve DD^2 my equation is A=(pi/4)*DD^2 should be simple.

Also when i have two vectors one is 9-1 and the other is 5-1 i want to divide the 5-1 / 9-1 but i want all possible soluitons? not just 5 results but 45 results.(the zip fuction only gives me 5 results)

Pls help 

Kind regards

How to put programmatically 2 dots above the first and the last digit  as in the example?

http://s017.radikal.ru/i419/1610/55/958cd75b6b34.png

Since the new editor for some reason I cannot upload any pictures or files from my computer.

Previous year I was using Maple 2015 and I had a procedure in which I had used

A := Array((1 .. 3)$3);

And similar use of $. This year I'm using Maple 2016. Now I came back to my old procedure but Maple doesn't compile the procedure anymore and instead shows

Error, `$` unexpected
What is the problem? Is something changed in new version of Maple?

Why I use Array and $ is my old question here http://www.mapleprimes.com/questions/210628-Undefined-For-Loop-Bound which was fine before.

Hi all, I need a heep to solve 6 PDEs from the first order with initial and boundry conditions.

Here is the file PDE_with_IBC-BC.mwPDE_with_IBC-BC.mw

Hi there,

I was wondering how to define the unit of an unspecified function. Here is what I want to do:

Say I have the coordinates of a Point in 1D-Space denoted by an unknown function x(t). While this function depends on time t the value of this function is supposed to be of SI Unit meter.

When calculating diff(x(t),t) I would like to get something like (absolut derivative of x(t)) * Unit(m/s).

So how do i tell maple that x(t) is something like f: time -> meter?
Also: How to specify that t has unit second without breaking the diff() command?

Any help would be greatly appreciated.

Regards

Zorg

Just curious as to how to find the Mathematics and Engineering dictionary in maple. 

In Maple 12 it was available in the help menu as Dictionary, which then pulled up as a help menu with folders a to z. 

In Maple 2016, I only noticed today, Dictionary is no longer a help option in the pull down menu.  Searching for dictionary brings up some of the files in the help menu but not sorted beautifully as M12.  In fact there is a definition list but it ends at d.

Am I missing something or is there a dictionary fault?