rxtracto_3D: Extract environmental data in a 3-dimensional box from an...
In rerddapXtracto: Extracts Environmental Data from 'ERDDAP™' Web Services

rxtracto_3D

R Documentation

Extract environmental data in a 3-dimensional box from an 'ERDDAP™' server using 'rerddap'.

Description

rxtracto_3D uses the R program 'rerddap' to extract environmental data from an 'ERDDAP™' server in an (x,y,z, time) bounding box. The same call could be made directly in rerddap, but function is maintained as it is used in the polygon routine.

Usage

rxtracto_3D(
  dataInfo,
  parameter = NULL,
  xcoord = NULL,
  ycoord = NULL,
  zcoord = NULL,
  tcoord = NULL,
  xName = "longitude",
  yName = "latitude",
  zName = "altitude",
  tName = "time",
  verbose = FALSE,
  cache_remove = TRUE
)

Arguments

`dataInfo`	- the return from an 'rerddap:info' call to an 'ERDDAP™' server
`parameter`	- character string containing the name of the parameter to extract
`xcoord`	- a real array with the x-coordinates of the trajectory (if longitude in #' decimal degrees East, either 0-360 or -180 to 180)
`ycoord`	- a real array with the y-coordinate of the trajectory (if latitude in decimal degrees N; -90 to 90)
`zcoord`	- a real array with the z-coordinate (usually altitude or depth)
`tcoord`	- a character array with the times of the trajectory in "YYYY-MM-DD" - for now restricted to be time.
`xName`	- character string with name of the xcoord in the 'ERDDAP™' dataset (default "longitude")
`yName`	- character string with name of the ycoord in the 'ERDDAP™' dataset (default "latitude")
`zName`	- character string with name of the zcoord in the 'ERDDAP™' dataset (default "altitude")
`tName`	- character string with name of the tcoord in the 'ERDDAP™' dataset (default "time")
`verbose`	- logical variable (default FALSE) if the the URL request should be verbose
`cache_remove`	- logical variable (default TRUE) whether to delete 'rerddap' cache

Value

If successful a structure with data and dimensions:

extract$data - the data array dimensioned (lon,lat,time)
extract$varname - the name of the parameter extracted
extract$datasetname - ERDDAP™ dataset name
extract$longitude - the longitudes on some scale as request
extract$latitude - the latitudes always going south to north
extract$time - the times of the extracts

else an error string

Examples

## toy example to show use
## and keep execution time low
##
# dataInfo <- rerddap::info('erdHadISST')
parameter <- 'sst'
xcoord <- c(-130.5, -130.5)
ycoord <- c(40.5, 40.5)
tcoord <- c('2006-01-16', '2006-01-16')
# extract <- rxtracto_3D(dataInfo, parameter, xcoord = xcoord, ycoord = ycoord,
#                        tcoord = tcoord)

## bathymetry example
## 2-D example getting bathymetry
## Wrap rerddap::info('etopo360') call in function that insures proper finish if it fails
dataInfo <- safe_info('etopo360')
parameter <- 'altitude'
# extract <- rxtracto_3D(dataInfo, parameter, xcoord = xcoord, ycoord = ycoord)

rerddapXtracto documentation built on Feb. 16, 2026, 1:06 a.m.