Displaying 1 result from an estimated 1 matches for "approxextrap".
2010 Apr 06
1
approx function wierd result
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 ad...