[R] lmodel2 - regression through origin?
ekwaters
ekwaters at unimelb.edu.au
Thu May 21 04:34:19 CEST 2009
Hi all,
is regression through the origin possible at all using lmodel2?
I tried the standard technique of inserting a minus 1 into the formula to
get regression through the origin in R, but the output still gives me an
intercept?
For comparison, this is me trying to do regression through the origin:
> test2.res<-lmodel2(mcr~m-1, data=test, "interval", "interval", nperm=99)
> test2.res
Model II regression
Call: lmodel2(formula = mcr ~ m - 1, data = test, range.y = "interval",
range.x = "interval", nperm = 99)
n = 13 r = 0.9801157 r-square = 0.9606268
Parametric P-values: 2-tailed = 4.491109e-09 1-tailed = 2.245554e-09
Angle between the two OLS regression lines = 0.440334 degrees
Permutation tests of OLS, MA, RMA slopes: 1-tailed, tail corresponding to
sign
A permutation test of r is equivalent to a permutation test of the OLS slope
P-perm for SMA = NA because the SMA slope cannot be tested
Regression results
Method Intercept Slope Angle (degrees) P-perm (1-tailed)
1 OLS -0.1053969 4.928172 78.52957 0.01
2 MA -0.1261714 5.122467 78.95373 0.01
3 SMA -0.1160872 5.028153 78.75177 NA
4 RMA -0.1167458 5.034313 78.76519 0.01
and below is the output and formula input when I omit the -1. Does lmodel2
function/ package not understand what I want?
> test1.res<-lmodel2(mcr~m, data=test, "interval", "interval", nperm=99)
> test1.res
Model II regression
Call: lmodel2(formula = mcr ~ m, data = test, range.y = "interval",
range.x = "interval", nperm = 99)
n = 13 r = 0.9801157 r-square = 0.9606268
Parametric P-values: 2-tailed = 4.491109e-09 1-tailed = 2.245554e-09
Angle between the two OLS regression lines = 0.440334 degrees
Permutation tests of OLS, MA, RMA slopes: 1-tailed, tail corresponding to
sign
A permutation test of r is equivalent to a permutation test of the OLS slope
P-perm for SMA = NA because the SMA slope cannot be tested
Regression results
Method Intercept Slope Angle (degrees) P-perm (1-tailed)
1 OLS -0.1053969 4.928172 78.52957 0.01
2 MA -0.1261714 5.122467 78.95373 0.01
3 SMA -0.1160872 5.028153 78.75177 NA
4 RMA -0.1167458 5.034313 78.76519 0.01
Ned
--
View this message in context: http://www.nabble.com/lmodel2---regression-through-origin--tp23646915p23646915.html
Sent from the R help mailing list archive at Nabble.com.
More information about the R-help
mailing list