Displaying 3 results from an estimated 3 matches for "meanvalue".
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2014 Nov 13
2
Help with ddply/summarize
I have a straightforward application of ddply() and summarize():
   ddply(MyFrame, .(Treatment, Week), summarize, MeanValue=mean(MyVar))
This works just fine:
   Treatment     Week MeanValue
1    MyDrug  BASELINE      5.91
2    MyDrug    WEEK 1      4.68
3    MyDrug    WEEK 2      4.08
4    MyDrug    WEEK 3      3.67
5    MyDrug    WEEK 4      2.96
6    MyDrug    WEEK 5      2.57
7    MyDrug    WEEK 6      2.50
8    P...
2008 Aug 12
1
Quickly calculating the mean results over a collection of data sets?
...xception of the Z values, so just
### copy the first test run data
testMeans <- data.frame(testRuns[[1]])
for(w0 in w) {
   for(y0 in y) {
     for (x0 in x) {
       row <- which(testMeans$W == w0 &
                    testMeans$Y == y0 &
                    testMeans$X == x0)
       meanValues <- sapply(testRuns,
                            function(r)
                            {mean( subset(r,
                                          r$W == w0 &
                                          r$Y == y0 &
                                          r$X == x0)$Z )})
       testMean...
2011 Mar 15
2
Calculate monthly means
I am trying to calculate monthly means by year of phosphates and nitrates from a multi year data set. Can anybody help me out with the most effective way to do this?
My data looks like this:
Collection_Date                   Test.Name              Value
2000-01-24 17:00:00            Phosphate               0.108
2000-01-24 17:00:00            Nitrate                     0.037
2001-11-12