cloud.calc {RGeostats}R Documentation

Calculate the Variogram Cloud

Description

Variogram Cloud calculation

Usage

cloud.calc(db, dbout = NA, dirvect = NA, 
        lagmax = NA, varmax = NA, lagnb = 100, varnb = 100, 
        toldis = 0.5, tolang = NA, bench = 0, cylrad = 0,
        opt.code = 0, tolcode = 0, dates = NA, flag.ask=FALSE, ...)

Arguments

db

The db-class containing the data information used to calculate the variogram cloud. The variogram cloud is calculated for the variable "z1" present in the DB. When present, the field "w" gives the weight attached to this sample.

dbout

The db-class containing the definition of the grid where the variogram cloud will be calculated. If not provided, the parameters must be provided by the user (lagmax,varmax)

dirvect

The directions in which the variogram must be calculated. For more information, refer to get.directions

lagmax

Maximum distance value for variogram cloud calculation. This value is disregarded when the argument dbout is provided.

varmax

Maximum variogram value for the variogram cloud calculation. This value is disregarded when the argument dbout is provided.

lagnb

Number of steps for the variogram cloud calculation along the distance axis.

varnb

Number of steps for the variogram cloud calculation along the variogram axis.

toldis

Tolerance on the distance, expressed as a percentage of the lag.

tolang

Array containing the angular tolerance for each calculation direction. If no angular tolerance is not defined, a default tolerance is calculated as one half of the angle. For one direction, if the angular tolerance is not defined, it is set to the default tolerance.

bench

When defined and positive, a par is discarded if the separation distance along the third axis is larger than 'banch'.

cylrad

When specified and positive, a pair is discarded if the seperation distance in the plane orthogonal to the calculation distance is larger than 'cylrad'.

opt.code

Option concerning the sample codes for constituting pairs:

  • 0 : a pair of samples is selected whatever their codes (if active)

  • 1 : a pair is retained if the code is active in the data base and the codes of the two samples are closer than tolcode

  • 2 : a pair is retained only if the codes of the two samples are different

tolcode

Maximum distance between the codes of the two samples.

dates

When defined and if the 'time' locator is defined, this value corresponds to the bounds of the Date Intervals. It is organized as follows:

  • The lower bound of the first Date Interval

  • The upper bound of the first Date Interval

  • The lower bound of the second Date Interval

  • The upper bound of the second Date Interval

  • ...

flag.ask

When TRUE, the variogram clpud is plotted. The user may then digitize a Polygon in order to identify the pairs which belong to this polygon. This operation is repeated until the user stops it.

...

Arguments passed to the functions db.plot used to represent the variogram cloud as a Db organized as a grid.

Value

The db-class organized as a regular 2-D grid where the variogram cloud is calculated. When no pair is obtained for a given cell, the value is set to FFFF.

See Also

db-class, vario-class,


[Package RGeostats version 11.0.6 Index]