Dear R-list members, I am calculating the linear extrapolation for a data set, using the function found in Hmisc.
x=c(0.0265,-0.0003,0.0142,0.0263,0.0634,0.1145,0.2504) y=c(58,107,152,239,362,512,724) x1=0.0393216 approxExtrap(x,y,x1, method="linear") approx(x,y,x1) #to see what is happening: plot(x, y, typ="o") abline(v=x1, col=8) Which gives x=0.03 and y=163, instead of the expectable which would be close to y=300. Any ideia why this is happening or how to sort this out? Thank you vey much in advance, Best wishes, Marta -- LNEG_VS_Poli_CMYK_300dpi Laboratório Nacional de Energia e Geologia, I.P. Estrada da Portela, Zambujal - Alfragide Apartado 7586, 2720-866 Amadora www.lneg.pt [[alternative HTML version deleted]]
______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.