vargen: Generate a field

In rcdo: Wrapper of 'CDO' Operators

Generate a field

Description

Generates a dataset with one or more fields

Usage

cdo_const(
  const = NULL,
  seed = NULL,
  grid = NULL,
  start = NULL,
  end = NULL,
  inc = NULL,
  levels = NULL,
  ofile = NULL
)

cdo_random(
  const = NULL,
  seed = NULL,
  grid = NULL,
  start = NULL,
  end = NULL,
  inc = NULL,
  levels = NULL,
  ofile = NULL
)

cdo_seq(
  const = NULL,
  seed = NULL,
  grid = NULL,
  start = NULL,
  end = NULL,
  inc = NULL,
  levels = NULL,
  ofile = NULL
)

cdo_stdatm(
  const = NULL,
  seed = NULL,
  grid = NULL,
  start = NULL,
  end = NULL,
  inc = NULL,
  levels = NULL,
  ofile = NULL
)

cdo_topo(
  const = NULL,
  seed = NULL,
  grid = NULL,
  start = NULL,
  end = NULL,
  inc = NULL,
  levels = NULL,
  ofile = NULL
)

Arguments

const	FLOAT - Constant
seed	INTEGER - The seed for a new sequence of pseudo-random numbers [default: 1]
grid	STRING - Target grid description file or name
start	FLOAT - Start value of the loop
end	FLOAT - End value of the loop
inc	FLOAT - Increment of the loop [default: 1]
levels	FLOAT - Target levels in metre above surface
ofile	String with the path to the output file.

Details

const   Create a constant field
        Creates a constant field. All field elements of the grid have the same value.
random  Create a field with random numbers
        Creates a field with rectangularly distrubuted random numbers in the interval \[0,1\].
topo    Create a field with topography
        Creates a field with topography data, per default on a global half degree grid.
seq     Create a time series
        Creates a time series with field size 1 and field elements beginning with a start value in time step 1
        which is increased from one time step to the next.
stdatm  Create values for pressure and temperature for hydrostatic atmosphere
        Creates pressure and temperature values for the given list of vertical levels.
        The formulas are:
        
        P(z) = P_0 * exp(-1 * g/R * H/T_0 * log( (exp(z/H)*T_0 + T_Delta)/(T_0 + T_Delta))
        T(z) = T_0 + T_Delta * exp(-z/H)
        
        with the following constants
        
        T_0     = 213 K           Offset to get a surface temperature of 288K
        T_Delta = 75 K            Temperature lapse rate for 10Km
        P_0     = 1013.25 hPa     Surface pressure
        H       = 10000.0 m       Scale height
        g       = 9.80665 m/s**2  Earth gravity
        R       = 287.05 J/kg*K   Gas constant for air
        
        This is the solution for the hydrostatic equations and is only valid for the
        troposphere (constant positive lapse rate). The temperature increase in the
        stratosphere and other effects of the upper atmosphere are not taken into
        account.

Value

Operators that output one or more files return a character vector to the output files.

Operators that output an indefinite number of files return a string with the basename of the files.

Operatos that don't return filenames return a character vector with the string output.

rcdo documentation built on June 8, 2025, 12:36 p.m.