prepare_group_data

This function prepares a dataset for grouped statistical tests by:
- Filtering out NA values in the target variable;
- Dropping empty groups and reporting excluded levels;
- Splitting the values by group and computing sample sizes.
Diese Funktion bereitet Daten fuer gruppierte Tests vor:
- Entfernt fehlende Werte (NA) in der Zielvariablen;
- Entfernt leere Gruppen und gibt eine Warnung aus;
- Teilt die Werte nach Gruppen und berechnet Stichprobengroessen.

Provides a set of exploratory data analysis (EDA) tools for
visualizing trends, diagnosing data types for beginner-friendly workflows,
and automatically routing to suitable statistical tests or trend exploration
models. Includes unified plotting functions for trend lines, grouped boxplots,
and comparative scatterplots; automated statistical testing (e.g., t-test,
Wilcoxon, ANOVA, Kruskal-Wallis, Tukey, Dunn) with optional effect size
calculation; and model-based trend analysis using generalized additive
models (GAM) for count data, generalized linear models (GLM) for continuous
data, and zero-inflated models (ZIP/ZINB) for count data with potential
zero-inflation.
Also supports time-window continuity checks, cross-year
handling in compare_monthly_cases(), and ARIMA-ready preparation with
stationarity diagnostics, ensuring consistent parameter styles for
reproducible research and user-friendly workflows.Methods are
based on R Core Team (2024) <https://www.R-project.org/>,
Wood, S.N.(2017, ISBN:978-1498728331),
Hyndman RJ, Khandakar Y (2008) <doi:10.18637/jss.v027.i03>,
Simon Jackman (2024) <https://github.com/atahk/pscl/>,
Achim Zeileis, Christian Kleiber, Simon Jackman (2008) <doi:10.18637/jss.v027.i08>.

Gelan Huang 

trendtestR

Exploratory Trend Analysis and Visualization for Time-Series and
Grouped Data

prepare_group_data function

<dl><dt>df</dt>
<dd>A data.frame or tibble containing the data.</dd>
<dt>value_col</dt>
<dd>A string indicating the name of the column with values to test.</dd>
<dt>group_col</dt>
<dd>A string indicating the name of the grouping column.</dd></dl>

Arguments

Prepare Grouped Data for Statistical Testing — prepare_group_data

<dl>

<dt>df</dt>
<dd>A data.frame or tibble containing the data.</dd>


<dt>value_col</dt>
<dd>A string indicating the name of the column with values to test.</dd>


<dt>group_col</dt>
<dd>A string indicating the name of the grouping column.</dd>

</dl>

prepare_group_data: Prepare Grouped Data for Statistical Testing

Description

Usage

Value

Arguments

Details