[R-sig-eco] urgent help required regarding GLS

[Caroline Dreßler]

*Dear R-Sig-Ecology,*

*I did a GLS analysis for my experiement which investigates the
abundance of bacteria influenced by the presence of contaminants and
different poresizes (of the microcomsm to enter for bacteria) over a
certain timeperiod (T1, T2, T3). The microcosms were filled with sand
which was spiked with contaminats. As a control no contamiants were
added to the sand: (contamination: contamin = contaminated sand,
noncontamin = noncontaminated sand. Futhermore, there were different
poresizes for the microorganisms to enter: (poresize: pore a = 2µm,
pore b = 30µm). The samples were analysed after three timepoints:
(timepoint: T1, T2, T3 = timepoint) *

*I got an significant result for the three-way-interaction
timepoint:poresize:contamination. Now I would like to show my results
in a graph with a linear regression for the different interactions.
But I don`t know how to calculate the intercepts as well as the slopes
for the following interactions: **timepoint:pore a:contamin**,
**timepoint:pore a:noncontamin, **timepoint:pore b:contamin,
**timepoint:pore b:noncontamin. *

*I am in urgent need of help. Somebody please give me a valuable
suggestion for my problem. Thanks a lot,*

Caro

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