The merge function combines 2, not 3 files at a time. Maybe
rich.stats2 = merge(rich.stats, Month, by="X.SampleID")
rich.stats3 = merge(rich.stats2, Location, by="X.SampleID")
Reading the manual page will help:
?merge
-------------------------------------
David L Carlson
Department of Anthropology
Texas A&M University
College Station, TX 77840-4352
-----Original Message-----
From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Lauren
O'Connell
Sent: Wednesday, March 11, 2015 11:02 AM
To: r-help at r-project.org
Subject: [R] Adding Column to a Data Frame
I am trying to add a column with data to a data frame that already has
information but am getting this error:
> rich.stats4 = merge(rich.stats,Location,Month,by="X.SampleID")
Error in fix.by(by.x, x) :
'by' must specify one or more columns as numbers, names or logical
I have two separate data frames that contain my sample names with location
and with month:
#Create data frame of all sample names and month sample was taken
Month
data.frame(X.SampleID=sample_data(Lauren5000)$X.SampleID,MonthSampleTaken=sample_data(Lauren5000)$MonthSampleTaken)
head(Month)
#Create data frame of all samples names and location of sample
Location
data.frame(X.SampleID=sample_data(Lauren5000)$X.SampleID,Location=sample_data(Lauren5000)$Location)
head(Location)
I was able to add my "MonthSampleTaken" variable by using this
command:
>rich.stats2 = merge(rich.stats, Month,by="X.SampleID")
> head(rich.stats2)
X.SampleID mean sd MonthSampleTaken
1 PE101 1421.34 19.44961 February
2 PE102 1336.24 25.43882 February
3 PE104 1418.75 21.92889 March
4 PE105 1331.03 20.55712 March
5 PE107 1320.21 20.91942 March
6 PE108 1328.41 20.49247 March
I now want to add my sample site location, but can't figure out how to do
this. Any help would be greatly appreciated.
Cheers,
Lauren
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