average: Fast Average for Large Spectral Dataset

In ChristianGoueguel/specProc: Preprocessing Tools For Laser-Induced Breakdown Spectroscopy (LIBS) Spectra

Fast Average for Large Spectral Dataset

Description

This function efficiently averages the samples spectra in a large dataset. It provides flexibility by computing either the overall mean across all spectra or group-wise means based on the values of a specified grouping column.

Usage

average(x, .group_by = NULL)

Arguments

x	A data frame or tibble.
.group_by	The column name to group the data by (optional). If not provided, the average of the overall data will be computed.

Details

The function leverages the power of Rcpp to perform the mean calculations in C++. The underlying C++ implementation has a time complexity of O(n × m), where n is the number of rows and m is the number of columns in the data. This efficient implementation ensures that the function can handle large datasets without significant performance overhead.

The R wrapper function adds minimal overhead for argument checking and data manipulation, while leveraging the efficient C++ implementation for the core computations. The overall time complexity remains O(n × m).

Value

• If .group_by = NULL, the function returns a numeric vector containing the mean of each column across all spectra.

• If .group_by is provided, the function returns a data frame with columns corresponding to the unique values in the grouping column. Each cell contains the mean of the corresponding column for that group.

Author(s)

Christian L. Goueguel

ChristianGoueguel/specProc documentation built on Nov. 9, 2024, 3:23 p.m.