Hello friends,

When I solve the optimization problem with restriction (below):

NLPSolve( ln(x1) +ln(x2+5), {x1 +x2 <=4}, assume = nonnegative);
     [-Float(infinity),

       [x1 = HFloat(0.0), x2 = HFloat(0.8333333333333334)]]

I get the expression  "-Float(infinity)"..

What do Float(infinity) and  HFloat(0.833333) mean?

Thanks for the attention,

Hello everybody!

I'm working on a statistical problem. I need to plot confidence regions for parameters in the model, but I don't know what I should do. I tried to get some programs from the internet, but either they don't work or I don't understand details of them to change for my work. Can someone introduce a good program to me?, or does anyone have another useful idea for me?

Thanks a lot!

I meet a problem in the use physcis package.

    for example,

                                   restart;  with(Physics); Setup(mathematicalnotation = true):

                  ...

I am analyzing a system that was at steady state and then subjected to a step change.  I have the steady state modeled with a system of ODEs.

I am going to model the step change with a system of PDE's.  The system will be discretized in space and time (z,t).  I know how to setup one side of the boundary conditions (0,t) for all variables, but the other (i.e A(z,0)) I would like to use the results of the steady analysis. Does anybody have some ideas on...

I would like to do the following

A[1,1],A[2,2],A[3,3]:=seq(i+2,i=1..3)

using seq on the left-hand-side. I know I have done it in the past but don't get it this time. End up with error messages. Not sure what am I missing.

thanks a lot

Dimitrios

Hello Maple experts,

I call "out"  the development of the sum(x^2, x=a..b):


"out":= sum(x^2, x=a..b);


            1        3   1        2   1     1   1  3   1  2   1  
out=     - (b + 1)  - - (b + 1)  + - b + - - - a  + - a  - - a

Hello All,

I am having a problem plotting the solution of a system of PDE's.  Maple evauates to a module, but when I try to plot any of the dependent variables (of space and time) vs time, all I get back is:

"PLOT(...)"

My module is called Final, and so my plotting command is as follows:

p1:=Final:-plot(A(z,t),t=0.5);

This is where I get "PLOT(...)".  Any help would be greatly appreciated!!! Thanks!

Hello.

I need to generate 200 random numbers from a normal(0,1). I used the following code:

N:=200:
Y:=Array(1..N):
for i from 1 to N by 1 do:
     Y[i]:=Generate(distribution(Normal(0,1))):
end do:

This code works. But the numbers generated aren't a random sample. You can check that in the following qqplot.

Dear my friends

Hi

I am solving a nonlinear differential equation by Maple. The equation is slarge. A large amount of memory is then required. I have a computer with 8 gigabytes memory. This memory o large and has many terms. Therefore, the algebraic expressions created in process of solving are so is very low to perform some commands of Maple such as "taylor" or "expand". I compel using the "restart" command to clear the memory after saving the results of each...

Let a:= (2x-1)/sqrt(1-4x²)  , b:=sqrt(1-2x)/sqrt(1+2x)

then c:=combine(a/b,radical,symbolic) is 1, it should be -1 !

(Multiply b top and bottom by sqrt(1-2x) to see this).

Am I misunderstanding combine?

Law of Hess and heats of dissolution in acid.^б-в Х, КХ

In 298.15 º K are set following the dissolution enthalpy of these compounds in HCl:

B₂O₃.3CaO           -344.86 kJ/mol,

B₂O₃.2CaO           -210.40 kJ/mol,

B₂O₃.CaO  ...

Hi I want to solve the following equation. For this I have written the following program. But Maple showing error.

eq := diff(x(t), `$`(t, 2))+326.1*(diff(x(t), `$`(t, 1)))+3190*(diff(x(t), `$`(t, 1)))^2-37500*sqrt(x(t)*(0.165e-2-x(t)))+2.825

ICs := x(0), Dx(0)-0

sol := dsolve({ICs, eq}, {x(t)}, type = numeric);

but it is showing 

Error, (in dsolve/numeric/process_input) system must be entered as a set/list of expressions/equations

Hello all,

In reference to Acer's workaround for the operator form of the optimization package, I'm having difficulty applying the method to an optimization problem with 7 variables. I'm hoping you can help me see what I'm doing wrong. This is what I've got coded, where EIG is a fairly long, complex procedure that outputs a float value:

> objf := proc (V::Vector)

If I use

with(plots):
plotsetup('bmp', 'plotoutput' = "F://try1.bmp");
pointplot([seq([i,i^2],i=1..100)],legend="F[u]");

every thing is fine but if I change this to

pointplot([seq([i,i^2],i=1..100)],legend=typeset(F[u]));

Maple evaluates for ever!

The above works fine for inline display.

Is there a way round this apart from exporting from inline?

Hello,

there is a problem puzzling me, plot(tan(x),view=[-10..10,-10..10],discont=true) can plot tan(x) correctly, but when using smartplot(tan(x)),it yields an unexpected picture.

Is there any way to plot tan(x) correctly only using smartplot?

Thank you.