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Last data update: 2014.03.03

R: Find and display patterns of zeros or unobserved values in a...

zPatterns

R Documentation

Find and display patterns of zeros or unobserved values in a data set

Description

This function summarises the patterns of zero or unobserved values in a data set and returns a vector of pattern numbers.

Usage

zPatterns(X, label = NULL, plot = TRUE,
             axis.labels = c("Component", "Pattern number"),
             bar.colors = c("red3", "red3"), bar.labels = FALSE,
             cell.colors = c("dodgerblue", "white"),
             cell.labels = c(label, paste("No", label)), cex.axis = 1.1,
             grid.color = "black", grid.lty = "dotted", legend = TRUE, ...)

Arguments

`X`	Data set (`matrix` or `data.frame` class).
`label`	Unique label (`numeric` or `character`) used to denote zero or unobserved values in `X`.
`plot`	Logical value indicating whether a graphical summary of the patterns is produced or not (default `plot=TRUE`).
`axis.labels`	Vector of axis labels for the table of patterns (format `c("x-axis","y-axis")`).
`bar.colors`	Colors for the margin barplots (format `c("col.top","col.right")`).
`bar.labels`	Logical value indicating if labels showing percentages must be added to the margin barplots (default `bar.labels=FALSE`).
`cell.colors`	Vector of colors for the table cells (format `c("col.unobserved","col.observed")`).
`cell.labels`	Labels for the cells (format `c("Unobserved","Observed")`, default `c(label,paste("No",label))`).
`cex.axis`	Axis labels scaling factor relative to default.
`grid.color`	Color of the grid lines (default `"black"`).
`grid.lty`	Style of the grid lines (default `"dotted"`, see `lty` in `par`).
`legend`	Logical value indicating if a legend must be included (default `legend=TRUE`).
`...`	Other graphical parameters.

Value

Vector of pattern IDs corresponding to each row of X.

It also prints a summary table showing zero or non-observation patterns and some summary statistics: number of zero/unobserved components by pattern (No.Unobs), pattern frequency (absolute and percentage), percentage zero/unobserved values by component (column) and overall percentage of zero/unobserved values in the data set. The symbols + and - indicate, respectively, zero/unobserved and observed components within each pattern. A graphical version of the summary table is returned including barplots on the margins displaying percentage zero/unobserved values by component (top) and percentage occurrence of the patterns in the data set (right).

Examples

data(LPdata)

pattern.ID <- zPatterns(LPdata,label=0)

LPdata[pattern.ID==5,]
LPdata[pattern.ID==7,]
LPdata[pattern.ID==10,]

# Modify cell labels and show percentages along with barplots
pattern.ID <- zPatterns(LPdata,label=0,
              cell.labels=c("Zero","Non-zero"),bar.labels=TRUE)