replace_zero function

Zero-Replacement

Multiplicative replacement of zeros. methods

## S4 method for signature 'CompositionMatrix'
replace_zero(x, value, delta = 2/3)

Arguments

• x: A CompositionMatrix object.
• value: A numeric vector giving the detection limits of each part (in $(0,1)$).
• delta: A numeric vector specifying the fraction of the detection limit to be used in replacement.

Returns

An CompositionMatrix object, where all zero values have been replaced.

Examples

## Data from Martín-Fernández et al. 2003
X <- data.frame(
  X1 = c(0.0000, 0.1304, 0.1963),
  X2 = c(0.1250, 0.3151, NA),
  X3 = c(0.1237, NA, NA),
  X4 = c(0.7253, 0.2002, 0.0819),
  X5 = c(0.0260, 0.3543, 0.0114)
)

## Coerce to a compositional matrix
Y <- as_composition(X)

## Replace zeros
Z <- replace_zero(Y, value = 0.02, delta = 2/3)
Z

References

Aitchison, J. (1986). The Statistical Analysis of Compositional Data. London: Chapman and Hall.

Martín-Fernández, J. A., Barceló-Vidal, C. & Pawlowsky-Glahn, V. (2003). Dealing with Zeros and Missing Values in Compositional Data Sets Using Nonparametric Imputation. Mathematical Geology, 35(3): 253-278. tools:::Rd_expr_doi("10.1023/A:1023866030544") .

See Also

Other imputation methods: missing, replace_NA()

Author(s)

N. Frerebeau