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rtidyrreshape2

Combining multiple rows into one row with multiple columns of data R

I have a dataset where the same effect was measured in different ways and I want to compare those measurements. My dataset looks like this:

Study     MType     ID     Insect     Mean     Sd     N
Alla      Fecundity  1      Aphid      .62      .7628  11
Alla      RGR        1      Aphid      -32.8    7.76   11
Ando      Survival   2      Bee        2.34     .67    8
Ando      RGR        2      Bee        4.56     .34    10
Ando      Fecundity  2      Bee        5.32     4.3    20

I want to combine the rows by ID number so that the MType, Mean, Sd and N for each row are preserved (although the column names need to change so the columns are distinguishable).

Hopefully, in the end it would look like:

Study ID Insect Fecundity.mean Fecundity.Sd Fecundity.N RGR.mean RGR.Sd...etc

Some difficulties:

  1. There are about 10 different MTypes
  2. each ID number has between 2 and 4 MTypes

I have messed around with reshape and with tidyr and I haven't been able to figure out how to do this with either of them. Please help!

Solution

  • You can use reshape via base R. You want to transform your data from long to wide format according to this post: How to reshape data from long to wide format?.

    If your data is in a data.frame d:

    reshape(d, idvar=c("ID", "Study", "Insect"), timevar = "MType", direction="wide")

    Results:

      Study ID Insect Mean.Fecundity Sd.Fecundity N.Fecundity Mean.RGR Sd.RGR N.RGR Mean.Survival Sd.Survival N.Survival
1  Alla  1  Aphid           0.62       0.7628          11   -32.80   7.76    11            NA          NA         NA
3  Ando  2    Bee           5.32       4.3000          20     4.56   0.34    10          2.34        0.67          8