Generate a field
vargen.Rd
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.