Hallo,
?Fit
"Fit[data, funs, vars] finds a least-squares fit to a list of data as a
\
linear combination of the functions funs of variables vars. The data can
have \
the form {{x1, y1, ... , f1}, {x2, y2, ... , f2}, ... }, where the
number of \
coordinates x, y, ... is equal to the number of variables in the list
vars. \
The data can also be of the form {f1, f2, ... }, with a single
coordinate \
assumed to take values 1, 2, ... . The argument funs can be any list of
\
functions that depend only on the objects vars."
also sind x1,x2,x3,x4 die Variablen und es soll f[x1,x2,x3,x4] berechnet
werden.
In den Daten muss also
{x1[i],x2[i],x3[i],x4[i],f[x1[i],x2[i],x3[i],x4[i]]}
die Funktionen sind also auch x1,x2,x3,x4 und
man bekommt:
Fit[data, {x1, x2, x3, x4}, {x1, x2, x3, x4}]
24.8902 x1 - 0.00471348 x2 + 0.0668466 x3 + 3.17493 x4
Gruss
Jens
"Dr. Heinrich Tersch" wrote:
>
> Hallo Mathematica-Freunde,
> kann jemand mal auf mein einfaches Problem schauen? Ich finde den Fehler
> nicht, bin anscheinend betriebsblind. Danke im voraus! H. Tersch
> Notebook:
> data ={{0,10,0,0,0.0517},
> {0,30,0,0,0.156},
> {0.03,10,0.5,0.3,0.67},
> {0.03,30,0.5,0.3,0.705},
> {0.06,20,0.5,0.3,1.34},
> {0.06,20,1,0.3, 1.587},
> {0.06,20,0.6,0.6,2.377},
> {0.06,20,1,0.6,2.646},
> {0.06,20,2,0.6,3.148},
> {0.06,20,2,1.2,5.221},
> {0.06,30,1,0.3,1.621},
> {0.1,20,0.5,0.3,2.207},
> {0.1,20,1,0.3,2.639},
> {0.1,20,1,0.6,4.332},
> {0.1,20,2,0.6,5.208},
> {0.1,20,2,1.2,8.547},
> {0.6, 100,1,0.3,15.86},
> {0.06,100,1,0.3,1.801},
> {0.06,200,1,0.3,2.046}};
> Fit[data,{x1,x2,x3,x4},{x1,x2,x3,x4,y}]
> Fit::"fitc":
> "Number of coordinates (\!\(4\)) is not equal to the number of
> variables \
> (\!\(5\))."
>
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