gs_mode

<p><code>data.table</code> object. This <code>data.table</code> where each cell
that lies within a larger grid cell is represented as a row. For each row,
the variable  <code>grid_id</code> is the ID of the cell from the coarser grid,
<code>sampled</code> denotes whether a cell has been sampled,  <code>stratum</code>
defines the stratum each cell lies within, and  <code>raster_index</code> is a
unique value for each cell in the raster.</p>

rast

<p>For each cell in the user-defined "coarse grid" used to select
spatially-representative samples (i.e. when <code>cfg_sample_spatial ==
TRUE</code>), this function calculates the stratum that occurs most often within
each course grid cell.</p>

Multi-stage cluster surveys of households are commonly performed by
governments and programmes to monitor population-level demographic, social,
economic, and health outcomes. Generally, communities are sampled from
subpopulations (strata) in a first stage, and then households are listed and
sampled in a second stage. In this typical two-stage design, sampled
communities are the Primary Sampling Units (PSUs) and households are the
Secondary Sampling Units (SSUs). Census data typically serve as the sample
frame from which PSUs are selected. However, if census data are outdated
inaccurate, or too geographically course, gridded population data (such as
<http://www.worldpop.org.uk>) can be used as a sample frame instead.
GridSample (<doi:10.1186/s12942-017-0098-4>) generates PSUs from
gridded population data according to user-specified complex survey design
characteristics and household sample size. In gridded population sampling,
like census sampling, PSUs are selected within each stratum using a
serpentine sampling method, and can be oversampled in urban or rural areas to
ensure a minimum sample size in each of these important sub-domains.
Furthermore, because grid cells are uniform in size and shape, gridded
population sampling allows for samples to be representative of both the
population and of space, which is not possible with a census sample frame.

gs_mode: Most common stratum calculator

Description

Usage

Arguments

Value