rerddapXtracto (version 0.4.5)

rxtracto: Extract environmental data along a trajectory from an 'ERDDAP' server using 'rerddap'.

Description

rxtracto uses the R program 'rerddap' to extract environmental data from an 'ERDDAP' server along a (x,y,z, time) trajectory.

Usage

rxtracto(dataInfo, parameter = NULL, xcoord = NULL, ycoord = NULL,
  zcoord = NULL, tcoord = NULL, xlen = 0, ylen = 0, zlen = 0,
  xName = "longitude", yName = "latitude", zName = "altitude",
  tName = "time", verbose = FALSE)

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 of the trajectory (usually altitude or depth)

tcoord

- a character array with the times of the trajectory in "YYYY-MM-DD" - for now restricted to be time.

xlen

- real array defining the longitude box around the given point (xlen/2 around the point)

ylen

- real array defining the latitude box around the given point (ylen/2 around the point)

zlen

- real array defining the depth or altitude box around the given point (zlen/2 around the point)

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

Value

A dataframe containing:

• column 1 = mean of data within search radius

• column 2 = standard deviation of data within search radius

• column 3 = number of points found within search radius

• column 4 = time of returned value

• column 5 = min longitude of call (decimal degrees)

• column 6 = max longitude of call (decimal degrees)

• column 7 = min latitude of call (decimal degrees)

• column 8 = max latitude of call (decimal degrees)

• column 9 = requested time in tag

• column 10 = median of data within search radius

• column 11 = median absolute deviation of data within search radius

Examples

# NOT RUN {
# toy example to show use
# but keep execution time down
# }
# NOT RUN {
dataInfo <- rerddap::info('erdHadISST')
# }
# NOT RUN {
parameter <- 'sst'
xcoord <- c(-130.5)
ycoord <- c(40.5)
tcoord <- c('2006-01-16')
xlen <- 0.01
ylen <- 0.01
extract <- rxtracto(dataInfo, parameter = parameter, xcoord = xcoord,
                    ycoord = ycoord, tcoord= tcoord,
                    xlen = xlen, ylen = ylen)
# }
# NOT RUN {
# 2-D example getting bathymetry
dataInfo <- rerddap::info('etopo360')
parameter <- 'altitude'
extract <- rxtracto(dataInfo, parameter, xcoord = xcoord, ycoord = ycoord,
                    xlen = xlen, ylen = ylen)
# }
# NOT RUN {
# }