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CADDIS Volume 4

Loading Data into R

How to Load Data into R

Data of various formats can be loaded into R. The sample data supplied in this module (see the Download Scripts and Sample Data page) is formatted as tab-delimited text and can be loaded using the following command:

data.set <- read.delim(filename)  # Loads a tab-delimited data file

Then, load these data files into R as follows:

site.species <- read.delim("site.species.txt")
site.species.or <- read.delim("site.species.or.txt") <- read.delim("") <- read.delim("")

Examine the data files you loaded and review how they are formatted:


The site-species data has a column with a site identifier and then a column for each taxon and a row for each site. Each numerical entry indicates the number of individuals for a given taxon and a given site.

The environmental data has a column with a site identifier and a column for each environmental variable (stream temperature, "temp"; and log-transformed percent sand and fines, "sed").

Next, merge data files so that each set of environmental data is matched with the appropriate biological data.

dfmerge <- merge(site.species,, by = "SITE.ID")
dfmerge.or <- merge(site.species.or,, by = "SITE.ID")

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