Optimal Stratification of Sampling Frames for Multipurpose Sampling Surveys
Adjustment of the sample size in case it is externally given
Builds the "strata" dataframe containing information on target variabl...
Builds the "strata" dataframe containing information on target variabl...
Function to assign the optimized strata labels
Multivariate optimal allocation
Builds the "sampling frame" dataframe from a dataset containing inform...
Builds the "sampling frame" dataframe from a dataset containing inform...
Builds the "strata" dataframe containing information on target variabl...
Builds the "strata" dataframe containing information on target variabl...
Checks the inputs to the package: dataframes "errors", "strata" and "s...
Function that allows to calculate a heteroscedasticity index, together...
Evaluation of the solution produced by the function 'optimizeStrata' b...
Expected coefficients of variation of target variables Y
Initial solution obtained by applying kmeans clustering of atomic stra...
Initial solution obtained by applying kmeans clustering of frame units
Initial solution obtained by applying kmeans clustering of frame units
Best stratification of a sampling frame for multipurpose surveys
Best stratification of a sampling frame for multipurpose surveys (only...
Best stratification of a sampling frame for multipurpose surveys consi...
Optimization of the stratification of a sampling frame given a sample ...
Plotting sampling rates in the different strata for each domain in the...
Plot bivariate distibutions in strata
Prepare suggestions for optimization with method = "continuous" or "sp...
Procedure to apply Bethel algorithm and select a sample from given str...
Selection of a stratified sample from the frame with srswor method
Selection of geo-referenced points from the frame
Selection of a stratified sample from the frame with systematic method
Information on strata structure
Execution and compared evaluation of optimization runs
Updates the initial frame on the basis of the optimized stratification
Assigns new labels to atomic strata on the basis of the optimized aggr...
Allows to transform a continuous variable into a categorical ordinal o...
In the field of stratified sampling design, this package offers an approach for the determination of the best stratification of a sampling frame, the one that ensures the minimum sample cost under the condition to satisfy precision constraints in a multivariate and multidomain case. This approach is based on the use of the genetic algorithm: each solution (i.e. a particular partition in strata of the sampling frame) is considered as an individual in a population; the fitness of all individuals is evaluated applying the Bethel-Chromy algorithm to calculate the sampling size satisfying precision constraints on the target estimates. Functions in the package allows to: (a) analyse the obtained results of the optimisation step; (b) assign the new strata labels to the sampling frame; (c) select a sample from the new frame accordingly to the best allocation. Functions for the execution of the genetic algorithm are a modified version of the functions in the 'genalg' package. M.Ballin, G.Barcaroli (2020) <arXiv:2004.09366> "R package SamplingStrata: new developments and extension to Spatial Sampling".
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