[R] Interpolation

Remigijus Lapinskas remigijus.lapinskas at maf.vu.lt
Wed Feb 12 14:09:03 CET 2003

Many thanks to all who replied to my e-mail. My problem was that I
had not known about the approx function.

By the way, if I have  x <- c(1990,1994,1995,1997), is there an
automated way to fill in the gaps, i.e., to get


Wednesday, February 12, 2003, 12:09:33 PM, you wrote:

PDB> Remigijus Lapinskas <remigijus.lapinskas at maf.vu.lt> writes:

>> Dear all,
>> I have two vectors and connect the points by line segments:
>> x <- c(1990,1994,1995,1997)
>> y <- c(30,40,80,20)
>> plot(x,y,type="l")
>> I want to get the values of y's on these lines at missing x's,
>> i.e., at 1991,1992,1993,and 1996. Is there a simple way to do this?

PDB> approx(x,y,c(1991,1992,1993,1996))
PDB> plot(x,y,type="l")
PDB> points(approx(x,y,c(1991,1992,1993,1996)),pch="*",col="red",cex=5)

PDB> --
PDB>    O__  ---- Peter Dalgaard             Blegdamsvej 3
PDB>   c/ /'_ --- Dept. of Biostatistics     2200 Cph. N
PDB>  (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
PDB> ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907

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