virtual_mixture: Create a virtual sediment mixture

In fingerPro: A Comprehensive Package for Sediment Source Unmixing

Create a virtual sediment mixture

Description

This function generates a virtual sediment mixture based on the characteristics of existing sediment sources and a set of user-defined apportionment weights. It effectively simulates a mixture with known source contributions.

Usage

virtual_mixture(data, weights)

Arguments

data	A data frame containing the characteristics of the sediment sources. Users should ensure their data is in a valid format by using the 'check_database()' function before running this function.
weights	A numeric vector representing the proportional contributions (apportionment values) of each source to the virtual mixture. The order of weights in the vector must correspond to the order of sources in the 'data' frame. The sum of 'weights' should ideally equal 1.

Details

A virtual mixture is a hypothetical sediment sample created by mathematically combining the tracer characteristics of known sources according to specified proportions ('weights'). This is a powerful tool in sediment fingerprinting for:

• **Consistency Checks**: Comparing observed mixture data against a virtual mixture can help assess the consistency of a dataset or the validity of an unmixing solution.

• **Scenario Testing**: Simulating mixtures under different hypothetical source contributions to understand how changes might affect sediment composition.

• **Model Validation**: Generating known virtual mixtures to test the accuracy and performance of unmixing models.

The function calculates the tracer values for the virtual mixture by taking the weighted average of the corresponding tracer values from each source.

Value

A data frame representing the virtual mixture. This data frame will have the same structure as a single row for a mixture in your input 'data', but with tracer values calculated based on the provided 'weights'.

fingerPro documentation built on Aug. 27, 2025, 5:11 p.m.