SN P
2007-Jul-15 00:35 UTC
[R] how to remove effects (distance as a covariate) in linear model
Hello, I am struggling to remove the effect of distance in the similarities of species composition between sites with the similarities of temperature between sites. Example: i have 4 columns (a column : sites name, b: species similarities between the two sites, c: environmental similarities between the two sites, and d: distance between the two sites Site A & site B, 0.34, 0.12, 2meter site A & site C, 0.56,0.45, 0.5meter Sites B &C, 0.76, 0.21, 0.98meter Sites D &A, 0.56, 0.76, 1.5meter Sites D & B, 0.01, 0.34, 7meter Sites A & D, 0.98, 0.78, 2 meter (note: , represents column) Here i want to fit the data to a general linear model in which the similarities values of the temperature variables calculated for each sites pair will be the independent observations and the respective correlation coefficients of species similarities will be the dependent observation. But I could not figure out how to control the effects of distance between each sites pair. How can I calculate it in R? Could you please help me? Syan _________________________________________________________________ Missed the show? Watch videos of the Live Earth Concert on MSN. [[alternative HTML version deleted]]