R Graphical Manual

Browse All

Last data update: 2014.03.03

R: Load all European Fluxes CSV files in one or more...

read_ef_files

R Documentation

Load all European Fluxes CSV files in one or more directories, bind all observations and fill missing data with NA_real

Description

European fluxes CSV files are distributed as one or more zip-compressed files from http://gaia.agraria.unitus.it . Once unzipped, all CSV files are to be found in uniquely identifed directories.

Usage

read_ef_files(dirs = getwd(), level_l = NULL, aggregation = NULL,
  fill_value = "-9999")

Arguments

`dirs`	a vector of directories where fluxes files are looked for. Defaults to current directory.
`level_l`	level of fluxes files (defaults to NULL). Allowed levels are (currently) 3 and 4. When NULL, either L3 and L4 files are looked for.
`aggregation`	aggregation of data (defaults to NULL) Allowed aggregations are (currently) "h" (half-hourly) and "d" (daily). When NULL, either "d" and "h" files are looked for.
`fill_value`	a code for a not available (NA) observation in CSV file. When the argument is given (default behaviour) the observations with 'fill_value' values are converted to NA_real

Details

All CSV files in that or those directories will be loaded and returned as a single row-wise bound data frame. The function assumes the file name pattern is like "^CEIP_EC_Ln_a_[a-zA-Z0-9]5_20[0-9]2_v[0-9]2.txt$" where n in level and a is aggregation period (optionally given as function arguments) Year, file name and site identification are added as fields in the returned data frame as 'efreadr_year', 'efreader_file_name' and 'efreader_site_id'.

Optionally (but default behaviour), unavailable measures are converted to 'NA_real' values.

Value

a data frame as loaded from the file, added with 'efreadr_year', 'efreadr_file_name' and 'efreadr_site_id' columns, and 'efreadr_date' column for half-hourly fluxes

Note

All files in the same directory should belong to the same aggregation/level combination in order to row-wise build a consistent dataframe. Note that when 'level_l' and/or 'aggregation' arguments are not given, all files will be loaded for in the directory, regardless of their level/aggregation.

For semi-hourly L4 aggregation (i.e. "h" aggregation in file name) the last row is reported as month 1, day 1, hour 00:00. A normal date conversion would convert this date to be the very first half-hour of the current year whereas it should be the very first half-hour of the following year. Therefore a class date field ('efreader_date') is added to the returned data frame holding the correct date (ie: January 1st of the following year).

Examples

dir_name <- system.file("extdata", package = "efreadr")
read_ef_files(dir_name)