R: Missing data pattern

md.pattern {mice} | R Documentation

## Missing data pattern

### Description

Display missing-data patterns.

### Usage

    md.pattern(x, plot = TRUE, rotate.names = FALSE)

### Arguments

`x` | A data frame or a matrix containing the incomplete data. Missing values are coded as NA's.
`plot` | Should the missing data pattern be made into a plot. Default is 'plot = TRUE'.
`rotate.names` | Whether the variable names in the plot should be placed horizontally or vertically. Default is 'rotate.names = FALSE'.

### Details

This function is useful for investigating any structure of missing observations in the data. In specific case, the missing data pattern could be (nearly) monotone. Monotonicity can be used to simplify the imputation model. See Schafer (1997) for details. Also, the missing pattern could suggest which variables could potentially be useful for imputation of missing entries.

### Value

A matrix with `ncol(x)+1` columns, in which each row corresponds to a missing data pattern (1=observed, 0=missing). Rows and columns are sorted in increasing amounts of missing information. The last column and row contain row and column counts, respectively.

### Author(s)

Gerko Vink, 2018, based on an earlier version of the same function by Stef van Buuren, Karin Groothuis-Oudshoorn, 2000

### References

Schafer, J.L. (1997), Analysis of multivariate incomplete data. London: Chapman&Hall.

Van Buuren, S., Groothuis-Oudshoorn, K. (2011). `mice`: Multivariate Imputation by Chained Equations in `R`. Journal of Statistical Software, 45(3), 1-67. https://www.jstatsoft.org/v45/i03/

### Examples

    md.pattern(nhanes)
    #     age hyp bmi chl
    #  13   1   1   1   1  0
    #   1   1   1   0   1  1
    #   3   1   1   1   0  1
    #   1   1   0   0   1  2
    #   7   1   0   0   0  3
    #   0   8   9  10 27

[Package mice version 3.12.0 Index]