SelectorChecker {startR}

Translate a set of selectors into a set of numeric indices

Description

This is a selector checker function intended for use as parameter 'selector_checker' in a Start() call. It translates a set of selectors which is the value for one dimension into a set of numeric indices corresponding to the coordinate variable. The function complies with the input/output interface required by Start() defined in the documentation for the parameter 'selector_checker' of Start().

Usage

SelectorChecker(selectors, var = NULL, return_indices = TRUE, tolerance = NULL)

Arguments

selectors

A vector or a list of two of numeric indices or variable values to be retrieved for a dimension, automatically provided by Start(). See details in the documentation of the parameters 'selector_checker' and '...' of the function Start().

var

A vector of values of a coordinate variable for which to search matches with the provided indices or values in the parameter 'selectors', automatically provided by Start(). See details in the documentation of the parameters 'selector_checker' and '...' of the function Start(). The default value is NULL. When not specified, SelectorChecker() simply returns the input indices.

return_indices

A logical value automatically configured by Start(), telling whether to return the numeric indices or coordinate variable values after the matching. The default value is TRUE.

tolerance

A numeric value indicating a tolerance value to be used in the matching of 'selectors' and 'var'. See documentation on '<dim_name>_tolerance' in ... in the documentation of the function Start(). The default value is NULL.

Value

A vector of either the indices of the matching values (if return_indices = TRUE) or the matching values themselves (if return_indices = FALSE).

Examples

# Get the latitudes from 10 to 20 degree
sub_array_of_selectors <- list(10, 20)
# The latitude values from original file
sub_array_of_values <- seq(90, -90, length.out = 258)[2:257]
SelectorChecker(sub_array_of_selectors, sub_array_of_values)