[R] fitting a curve to data points

[Carlos "Guâno" Grohmann]

Hello all. This is likely to be a silly question, but I have a set of
data points and I want to fit a curve to it, like this:
http://www.igc.usp.br/pessoais/guano/temp/curve.png.

which function should I use?

many thanks

Carlos

-- 
+-----------------------------------------------------------+
              Carlos Henrique Grohmann - Guano
  Geologist M.Sc  - Doctorate Student at IGc-USP - Brazil
Linux User #89721  - carlos dot grohmann at gmail dot com
+-----------------------------------------------------------+
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