Re: Calc formula from table
- To: mathgroup@smc.vnet.net
- Subject: [mg10822] Re: [mg10808] Calc formula from table
- From: jpk@max.mpae.gwdg.de
- Date: Tue, 10 Feb 1998 21:01:36 -0500
Hi
x={30, 40 , 50 , 60, 70 , 80, 90, 100, 110, 120, 130, 140,
150}; y={338.7, 263.5, 198.6, 150.5 , 114.7, 80.3, 55.5, 41.9, 30.2,
19.3, 16.5, 12.4, 10.1};
data=Transpose[{x,y}];
fun=Fit[data,{1,X,X^2,X^3},X]
return
651.3037962048336 -
12.94513569797418*X +
0.0895608141903066*X^2 -
0.0002119172494346388*X^3
Is this OK four You?
Hope that helps
Jens
> Could anyone help me: I need to know how to calculate a third order
> parabolic
> formula from a table. I.o.w. I have a table of data and I need a manual
> way to calculate the formula for the curve of the data . 3rd order
> formula to be obtained:
> Y=AX**3 + BX**2 + CX + D
>
> example data:
> y = 338.7 263.5 198.6 150.5 114.7 80.3 55.5 41.9
> 30.2 19.3 16.5 12.4 10.1
> x= 30 40 50 60 70 80 90
> 100 110 120 130 140 150
>
> answer: Y=-0.0002X**3 + 0.0896X**2 -12.945X +651.3
>
> I need a manual method to calculate this formula.
>
> Can it be done without using integration/differentiation. Maybe lin log
> exp?
>
> Answers will be appreciated. Regards, Pieter.
>
>