sample_stratified

for internal use only! This is stratified sampling based on the
values of a continuous response variable (y). If group is provided, the
sampling is done based on the groups and the average of y per group. This
function is used to create calibration and validation groups for
leave-group-out cross-validations (or
leave-group-of-groups-out cross-validation if group argument is provided).

internal

Functions for dissimilarity analysis and memory-based learning
(MBL, a.k.a local modeling) in complex spectral data sets.
Most of these functions are based on the methods presented in
Ramirez-Lopez et al. (2013) <doi:10.1016/j.geoderma.2012.12.014>.

Leonardo RamirezLopez

resemble

Memory-Based Learning in Spectral Chemometrics

sample_stratified function

<dl><dt>y</dt>
<dd>a matrix of one column with the response variable.</dd>
<dt>p</dt>
<dd>the percentage of samples (or groups if group argument is used) to
retain in the validation_indices set</dd>
<dt>number</dt>
<dd>the number of sample groups to be crated</dd>
<dt>group</dt>
<dd>the labels for each sample in <code>y</code> indicating the group each
observation belongs to.</dd>
<dt>replacement</dt>
<dd>A logical indicating sample replacements for the
calibration set are required.</dd>
<dt>seed</dt>
<dd>an integer for random number generator (default <code>NULL</code>).</dd></dl>

Arguments

A function to create calibration and validation sample sets for
leave-group-out cross-validation — sample_stratified

<dl>

<dt>y</dt>
<dd>a matrix of one column with the response variable.</dd>


<dt>p</dt>
<dd>the percentage of samples (or groups if group argument is used) to
retain in the validation_indices set</dd>


<dt>number</dt>
<dd>the number of sample groups to be crated</dd>


<dt>group</dt>
<dd>the labels for each sample in <code>y</code> indicating the group each
observation belongs to.</dd>


<dt>replacement</dt>
<dd>A logical indicating sample replacements for the
calibration set are required.</dd>


<dt>seed</dt>
<dd>an integer for random number generator (default <code>NULL</code>).</dd>

</dl>

sample_stratified: A function to create calibration and validation sample sets for leave-group-out cross-validation

Description

Usage

Value

Arguments