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Cronus database classes

Source: R/02_classes.R
Database-class.Rd

cronus creates a database, which takes the form of a 5-level directory. These levels are Region > Sector > Provider > Product > Variable.

Value

An S4 object of the appropriate class (constructor functions).

Details

For a specific region, data can belong to one of three sectors: agricultural, environmental or satellite. Data are made available by a provider, usually an organization or a lab, which organizes the data in one or more products. Each product contains several variables of interest.

The class tree structure is the following:

  • Agricultural Sector

    • Nass Provider

      • Quickstats Product

        • Progress Variable

      • Cropmaps Product

    • Bibliography Provider

      • Parameters Product

  • Environmental Sector

    • Ornl Provider

      • Daymet Product

  • Satellite Sector

    • Modis Provider

      • Mod09ga Product

      • Myd09ga Product

    • Landsat Provider

      • Landsat_tm_c1 Product

      • Landsat_etm_c1 Product

      • Landsat_8_c1 Product

    • Sentinel Provider

      • S2msi2a Product

      • Sy_2_syn___ Product

Classes Database, Sector, Provider, and Product are also defined, but are abstract classes that exist solely for hierarchical purposes.

All classes are defined with the S4 OOP system, except from the Variables that are defined using the S3 OOP system. Each variable has its own documentation page.

Slots

region

Region. A region of interest.

date

Date. Dates of interest (vector).

dir

character. The database parent directory. If the path_demeter environment variable has been set, it can be omitted.

See also

set_path_demeter()

Examples

if (FALSE) {
region <- Region(name = "nebraska", type = "us state",
                 div = c(country = "United States", state = "Nebraska"))
date <- as.Date("2020-07-15")
dir <- getwd()

w <- new("Quickstats", region = region, date = date, dir = dir)
x <- new("Cropmaps", region = region, date = date, dir = dir)
y <- new("Daymet", region = region, date = date, dir = dir)
z <- new("Mod09ga", region = region, date = date, dir = dir)

}