NA_plot function

Graphical Tool for Visualizing NAs in a Data Set

Plot NAs in a data set.

NA_plot(x, col = c("black", "white"), xlab = "Time", ylab = "Component",
        text = "Black: NA; White: Available data",
        side = 4, line = 1, adj = 0, ...)

Arguments

• x: matrix (ideally an xts object).
• col: bivariate vector containing the colors for missing and available data, respectively.
• xlab: x-axis label.
• ylab: y-axis label.
• text: see mtext(). The text = "", it is omitted.
• side: see mtext().
• line: see mtext().
• adj: see mtext().
• ...: additional arguments passed to the underlying image().

Returns

invisible().

Details

Indicate NAs in a data set.

Author(s)

Marius Hofert

Examples

## Generate data
n <- 1000 # sample size
d <- 100 # dimension
set.seed(271) # set seed
x <- matrix(runif(n*d), ncol = d) # generate data

## Assign missing data
k <- ceiling(d/4) # fraction of columns with some NAs
j <- sample(1:d, size = k) # columns j with NAs
i <- sample(1:n, size = k) # 1:i will be NA in each column j
X <- x
for(k. in seq_len(k)) X[1:i[k.], j[k.]] <- NA # put in NAs

## Plot NAs
NA_plot(X) # indicate NAs