What is wrong?

Questions
,
1

Hi,
I’m using Mathematica 9. I made some code (full code update):

Data = Import["E:\\EuFe2As2-based\\Math\\Cp\\Cp_Eu12A1_t4", "Table"];
pun = Select[Data,  First[#] > 150 &];
ListPlot[pun]
CDeb[n_, t_, thD_] = n*9*8.31 (t/thD)^3 Integrate[ x^4 Exp[x]*(Exp[x] - 1)^-2, {x, 0, thD/t}];
CEl[t_, gamma_] = gamma*t;
Cp[n_, t_, thD_, gamma_] = CDeb[n, t, thD] + CEl[t, gamma];
n = 5;
fitt = FindFit[pun, Cp[n, T, ThetaD, GammA], {{ThetaD, 330}, {GammA, 0.1}}, T];
modelFunk = Function[{T}, Evaluate[Cp[n, T, ThetaD, GammA] /. fitt]];

Plot[modelFunk[T], {T, 0, 300}, Epilog -> Map[Point, pun]]
tablica = 
Table[{Temp, Re[CEl[Temp, GammA] /. fitt], Re[CDeb[n, Temp, ThetaD] /. fitt], Re[modelFunk[Temp]]}, {Temp,   0.1, 30, 5];

Export["c:/daneCp.csv", tablica, "CSV"]

and in the line with the FindFit I got somthing like this:
FindFit::nrlnum: The function value {Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined} is not a list of real numbers with dimensions {39} at {ThetaD,GammA} = {330.,0.1}. >>
FindFit::nrlnum: The function value {Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined,Undefined} is not a list of real numbers with dimensions {39} at {ThetaD,GammA} = {330.,0.1}. >>

I have no idea what’s going on with it. The line with FindFit works fine in mathematica 7, but in 9 doesn’t. Any suggestions?

2

What does Exp mean in your definition for CDeb?

Please first check that your functions, CDEB, CDEI and Cp all work as you intend them to.

3

exp(x) but you can’t see it here. I don’t know why. As i said, everything works fine in Mathematica 7, but not 9, there is always a problem with FindFit. Some problems with Theta and GammA but what? Syntax? I don’t know where.

4

Hi Taksido,
Please insert your code in a spikey box, like this:

eq = a x + b/(1 + Exp[-c (x - x0)]) + d;

The text editor does funny things, but the spikey box preserves code we can see, and cut and paste.
Best,
David

5

“pun” is not defined the way you want.

FindFit::nrlnum: The function value {Undefined,Undefined,..,Undefined,Undefined} is not a list of real numbers

Previously, your code defined the list “pun” by inserting “Undefined” everywhere.

In[1]:= ?Undefined                                                                      
Undefined is a symbol that represents a quantity with no defined value.

You should consider attaching a complete notebook that works in Mathematica 7. Verify that you can open Mathematica, run only the notebook, and get the right results.

6

The code has been updated