Hej hej,

is there a way to obtain confidence intervals for the parameters in a NonlinearFit? To give you an impression of the problem which I was working on, I created a minimial working example (not sure wheather that actually helps). In this particular case, I have two parameters to fit the coefficients of a binomial series to some data I obtained. Beyond the values of the parameters (in a least square fit), I'm also interested in some kind of confidence interval, to get a feeling about how realiable my values are. Is there a direct (or even indirect) way to obtain such a thing. Either directly as a Maple function (confidenceintervals is not supported for NonlinearFit, if I'm not mistaken) or as something I can implement myself (within a reasonable time frame, as in hours rather than days).
Thanks in advance!

Cheer,

Sören

Download nonlinearfit-problem.mw

I'm trying to use Maple to show that the Hilbert transform of the natural log of |H(jw)| is -arctan(H(jw))

for a minimum phase network; The network I choose is the simplest filter there exists i.e. a low pass RC-filter

with transfer function H(jw)=1/(1+tau*j*omega) therefore |H(jw)|=1/sqrt(1+(tau*omega)^2))

Here is what I did:

assume(omega > 0); assume(tau > 0); interface(showassumed = 0);

result5 := (int((1/2)*log(1+(tau*nu)^2)/(nu-omega), nu = -infinity .. infinity, CauchyPrincipalValue))/Pi

simplify(result5, symbolic)

unfortunately this does not give me the expected result: -arctan(w*tau*omega)

can anyone here tell me what the right way to do it is?

thanks in advance

hugo

Dear Community Members,

We have problem with calculation in Maple v11 and v18. when we make a calculation by using maple v11 and v18, we was not able to get the solution as you see enclosed. when we clicked to "enter + ; ", programme does not run.

Dear all

I want to know, how one can install third party package into Maple13, the package is "wkptest" i downloaded it from link http://cpc.cs.qub.ac.uk/summaries/ADTY. If anyone knows how to do this please help.

When I create a component, here a label component, and set a name property and then click OK, that name seems to go into some list never to be erased. If I then delete the first name and put in a new name and click OK. thus saving it, and the then try to use that name again on a different component, I am told that the name is already in use. Well, no existing component has the name, but it is still in Maple's list of components. If I go to edit an action for any component and input %+command completion, I get a list of components which includes the deleted name which does not belong to any existing component. Since the name is on this list, I cannot reuse the component name.

How do I clean up this erroneous list of component names, so that a mistake in naming one component doesn't forever prevent me from using it on the component for which it was intended?

I run the same notebook in Maple 2015 that I used to run in Maple 18.02.

I noticed that it no longer auto-scroll when the print messages reached the bottom of the window as it did with Maple 18.02. This means, I can't see which line the computation is at at the moment, since I can't see the last line printed (it is not visible), without me having to manually use the vertical slider to scroll down trying to catch up with it. But it is hard to do this all the time.  It starts to scroll ok until the last printed message reached the bottom of the window, but then it stops.

This is very annoying, becuase I'd like to see the messages as it is running, so I know which equation is being solved when I look at the screen.  The messages are like this, with some print message I put in the loop

memory used=0.53MiB, alloc change=0 bytes, cpu time=16.00ms, real time=7.00ms, gc time=0ns
*** loop counter 100
etc..

Is there an option one has to configure to make the screen scoll with the output? I looked but do not see one now.

I do not remember having to do anything in Maple 18.02. It seems natural that it should scroll down as messages are being displayed. This is how all apps work.  

I am using Maple 2015, windows 7, 64 bit OS and 64 bit Maple. Using Worksheet, was created in Maple 18.02. Other than this, everything else works ok so far.

interface(version);
Standard Worksheet Interface, Maple 2015.0, Windows 7, February 17 2015 Build ID 1022128

thank you

Hello every one,

I am trying to solve a backward induction problem (game theoretic problem) in maple. Lets say we have S rounds. I start from bottom (S-th round) and solve a parametric equation. Then I put the solution in the upper level (S-1). Then, update the functions at level and solve the equation pertatining to this level (S-1). Again, I put the solution ofround S-1 into the equations of S-2 and update the equations and parametrically solve the equation belonging to level S-2 . This process repeats till the first level.

The issue is that the solution gradually becomes larger and larger. I guess that's why Maple is not able to solve it. 

Have any of you guys faced to a similar problem. Any suggestion?

I was thinking of asking maple to reduce its precision in computations. I mean there may not be necessary to store a number with 100 digits precision! However, I don't know how to do that (I don't know the command). Any suggestion?

Thank you in advance.

Ahmadreza

Hi! I'm having trouble with the MapleSim "Equation Extraction" template. I have an extremely simple dynamics scenario with RigidBody at a particular position in a world; when the simulation starts, the body should simply start fallin with a constant acceleration, and I'm looking to extract kinematic equations for this situation.

However, the problem I have with the extracted equations is that they contain some rotational dependent terms that I wish to avoid - a lot of sines and cosines with arguments that I actually cannot match up to any variables in the model, or when I enable quaternion representation, terms like this:

What I don't understand is what exactly these rotation terms represent. The object should be falling straight downwards, and gravitation should be applied straight downwards, and when I start the simulation it does run through, also indicating that there should be no unbound variables. I'm not sure exactly what parameters in the Modelica model do they correspond to? I did not find any such angles in the object settings. And can I ask MapleSim to generate equations without these unbound rotation variables?

Using Maple 18, I solved for minimum and maximum price. Instead of using fsolve I wanna use procedure programming structure in order to get the same results. How can I do it?

min_sol := fsolve([bc_cond, slope_cond, x[G, 1] = w[aggr, 1]], {p = 0 .. 1, x[G, 1] = 0 .. w[aggr, 1], x[G, 2] = 0 .. w[aggr, 2]}); p_min := subs(min_sol, p); max_sol := fsolve([bc_cond, slope_cond, x[G, 2] = w[aggr, 2]], {p = 0 .. 1, x[G, 1] = 0 .. w[aggr, 1], x[G, 2] = 0 .. w[aggr, 2]}); p_max := subs(max_sol, p);
{p = 0.3857139820, x[G, 1] = 127.8000000, x[G, 2] = 38.99045418}
0.3857139820
{p = 0.8841007104, x[G, 1] = 44.30160890, x[G, 2] = 164.2000000}
0.8841007104

Hi,

I am trying to realize the following calculation in Maple.

$
  \left[\sum_{i=0}^n y_i(x) \partial_x^i , \sum_{j=0}^m z_j(x) \partial_x^j \right]  \\
=   \sum_{i=0}^n \sum_{j=0}^m \sum_{l=0}^i  \binom il y_i(x) \left( \partial_x^{i-l} z_j(x)\right) \partial_x^{l+j} \\
- \sum_{j=0}^m \sum_{i=0}^n \sum_{l=0}^j  \binom jl z_j(x) \left( \partial_x^{j-l} z_i(x)\right) \partial_x^{l+i} \ .

$

Is there a way to make maple understand d/dx as a differential opperator and calculate with it? When i for example try to calculate diff(d/dx, x) it should give me d^2/dx^2 as a result. Unfortunately i don't know how to realize this.

Basic problem is i don't know how to realize operator expressions in maple like for example:

f(x) d/dx      ( f(x) is a smooth function of x here )

where when applied to a function h(x) it should result in f(x) d/dx h(x) .

Is that possible?

Thank you very much in advance.

What I tried is at

http://apfp.sourceforge.net/maple_interval_arith.pdf

I would like to be able to do comparisons of intervals.

At least take min or max - I thought I saw that on help pages but didn't get it to work.

Would also like to use with complex numbers - tried evalrC - but did not do what I expected.

Hello,

please explain how to write a code to calculate and output the actual area using integration for y=X^3 over range (0,2) using left-hand rule and 200 subdivisions?

Thank you 

I currently have a function quadsum(n) that determines the [x,y] solutions of the above equation for an integer n. :

quadsum:= proc(n::nonnegint)
local
k:= 0, mylist:= table(),
x:= isqrt(iquo(n,2)), y:= x, x2:= x^2, y2:= y^2;
if 2*x2 <> n then x:= x+1; x2:= x2+2*x-1; y:= x; y2:= x2; end if;
while x2 <= n do
y:= isqrt(n-x2); y2:= y^2;
if x2+y2 = n then k:= k+1; mylist[k]:= [x,y] end if;
x:= x+1; x2:= x2+2*x-1;
end do;
convert(mylist, list)
end proc:

How would I alter this so that I get [x,y] for n= (5^a).(13^b).(17^c)(29^d) for non-negative integers a,b,c,d?

please is there any one can help me to find a solution of a sytem of 3 non linear equations each with 3 variable and with more than 30 unknown coefficients

this is the system

solve({EEE_x(x, y, z) = 0, EEE_y(x, y, z) = 0, EEE_z(x, y, z) = 0}, {x, y, z})

where x,y,r are the unknowns

and the three equations are simply the partial derivative with respect to x,y and z repectively

EEE_x(x,y,z):=(&DifferentialD;)/(&DifferentialD; x) EE(x,y,z)

EEE_y(x,y,z):=(&DifferentialD;)/(&DifferentialD; y) EE(x,y,z)

EEE_z(x,y,z):=(&DifferentialD;)/(&DifferentialD;z)EE(x,y,z)

the main equation is EE where (it has 3 variables and more than 30 qunknowns coefficients

(x, y, z) ->

1
----------------------------------------------------------------
2
/ 2 2 2\
hh \ii + jj x + ll z + mm y + 100. y + nn y z + oo x + pp z /

/ 2 2 2 2 3 2
\p z y + q z y + l z x + g z x + o z y + n z x + m y x

2 2 2 3 2 2 2
+ j y x + k y x + i z y + d z y + f z x + h z y

2 2 4 3 2 3
+ e y x + u z y x + v z y x + a + b x + c x + r x + s z

2 2 4 3 4 \
+ t z + bb z + cc y + dd y + ee y + ff y + gg z + aa x/

1.  a procedure quadsumstats whose input is an integer n. This procedure should return a list of length 

n whose kth  entry is the number of solutions to
x^2 + y^2 = k 
for
1 <= k and k <= n

I am sort of confused as to how to construct that list of length n and how to obtain integer solutions to the equation in maple.

2.

a procedure firstCount(k) that finds the first integer
n
with
k
representations as
"x^2+y^2= n." What does it mean for an integer to have k representations?