[R] Calculate x-values from a spline

[Cuvelier Etienne]

Gunther Höning a écrit :
> Hello,
> 
> I calculate splines from messured points(x,y) of an unknown function f(x).
> e.g.
> x <- c(0.004115, 0.012345, 0.037037, 0.111110, 0.333330, 1.000000)
> y <- c(37, 50, 45, 60, 50, 66)
> w <- c(0.8540541, 0.8320000, 0.8822222, 0.7983333, 0.8220000, 0.8151515) as
> weights
> f <- smooth.spline(x,y,w)
> 
> Now I have y-values and want to calculate the x-value(s) from this spline.
> There is no further limitation to the spline, like monotonicity or anything
> else..
> 
> Does anyone know how to do this ?

Perhaps this ?

finv = splinefun(f$y,f$x)

> 
> Gunther
> 
> 
> 
> gunther.hoening at ukmainz.de
> 
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> 
> 
> 

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Cuvelier Etienne
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