[R] how to use glm for a time course data set

[Jin, Jp]

Dear list,

I used glm to analyze the effect of treatment, measurement-methods etc. on lesion size in a time course experiments. Could anyone points me out how to extract detailed comparisons of interest?  For example:

Measurement.T2.M6 vs. Measurement.T2.Baseline, Or even
Measurement.T2.M6.Treatment vs. Measurement.T2.M6.placebo (I did not include Treatment as a factor in the query below yet).

 Thanks for your help (data was attached)!

Jp Jin

> summary(glm(data$Lesion.Size~Time+Measurement+Time*Measurement, data=data))

Call:
glm(formula = data$Lesion.Size ~ Time + Measurement + Time *
    Measurement, data = data)

Deviance Residuals:
    Min       1Q   Median       3Q      Max
-5344.9  -2494.8  -1289.5    981.7  29248.7

Coefficients:
                      Estimate Std. Error t value Pr(>|t|)
(Intercept)             1352.7     1180.6   1.146   0.2546
Timem12                  708.4     1669.7   0.424   0.6723
Timem6                   630.6     1669.7   0.378   0.7064
MeasurementT2           4079.8     1669.7   2.443   0.0163 *
Timem12:MeasurementT2  -2400.5     2361.3  -1.017   0.3117
Timem6:MeasurementT2   -1763.5     2361.3  -0.747   0.4569
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

(Dispersion parameter for gaussian family taken to be 25090570)

    Null deviance: 2787055253  on 107  degrees of freedom
Residual deviance: 2559238182  on 102  degrees of freedom
AIC: 2154.4

Number of Fisher Scoring iterations: 2


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