reshape2

I was looking at similar questions but I couldn't find a case similar to mine. I have a data frame that for each subject, has multiple observations per condition. It looks like this: subject <- c(rep("S1",4), rep("S2",4)) condition <- rep(c(rep("a",2), rep("b",2)),2) value <- c(1:8) df <- data.frame(subject,condition,value) df subject condition value S1 a 1 S1 a 2 S1 b 3 S1 b 4 S2 a 5 S2 a 6 S2 b 7 S2 b 8 I would like to reshape it to look like this: subject condition.a condition.b S1 1 3 S1 2 4 S2 5 7 S2 6 8 I have tried reshape and cast , but they give me an error message because there are

How do I get Pivots with subtotals (like in MS Excel Pivot Tables) in R? I am using dcast from reshape2 package to create pivots in R. I also got grand totals working using rowSums and colSums . I admit I do not understand the intricacies in the dcast parameter set. I just know how to create the pivot and the help file is going over my head. It will be extremely helpful if someone can solve this using dcast (I suspect it can do it all), and explain the parameters necessary for the solution. I am using this code (C2 has two factors, X1 & X2): PIV <- dcast(DF, C1~C2, value.var="C3", sum) I am

I have data that looks like this: sample start end gene coverage X 1 10 A 5 X 11 20 A 10 Y 1 10 A 5 Y 11 20 A 10 X 1 10 B 5 X 11 20 B 10 Y 1 10 B 5 Y 11 20 B 10 I added additional columns: data$length <- (data$end - data$start + 1) data$ct_lt <- (data$length * data$coverage) I reformated my data using dcast: casted <- dcast(data, gene ~ sample, value.var = "coverage", fun.aggregate = mean) So my new data looks like this: gene X Y A 10.00000 10.00000 B 38.33333 38.33333 This is the correct data format I desire, but I would like to fun.aggregate differently. Instead, I would like to take a