misty (version 0.6.7)

as.na: Replace User-Specified Values With Missing Values or Missing Values With User-Specified Values

Description

The function as.na replaces user-specified values in the argument na in a vector, factor, matrix, array, list, or data frame with NA, while the function na.as replaces NA in a vector, factor, matrix or data frame with user-specified values in the argument na.

Usage

as.na(..., data = NULL, na, replace = TRUE, check = TRUE)
na.as(..., data = NULL, na, replace = TRUE, as.na = NULL, check = TRUE)

Value

Returns a vector, factor, matrix, array, data frame, or list specified in the argument ... or a data frame specified in data with variables specified in ... replaced.

Arguments

...

a vector, factor, matrix, array, data frame, or list. Alternatively, an expression indicating the variable names in data e.g., as.na(x1, x2, data = dat). Note that the operators ., +, -, ~, :, ::, and ! can be used to select variables, see 'Details' in the df.subset function.

data

a data frame when specifying one or more variables in the argument .... Note that the argument is NULL when specifying a vector, factor, matrix, array, data frame, or list for the argument ....

na

a vector indicating values or characters to replace with NA, or which NA is replaced.

replace

logical: if TRUE (default), variable(s) specified in ... are replaced in the argument data.

check

logical: if TRUE (default), argument specification is checked.

as.na

a numeric vector or character vector indicating user-defined missing values, i.e. these values are converted to NA before conducting the analysis.

Author

Takuya Yanagida

References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

See Also

na.auxiliary, na.coverage, na.descript, na.indicator, na.pattern, na.prop, na.test

Examples

#-------------------------------------------------------------------------------
# Numeric vector
num <- c(1, 3, 2, 4, 5)

# Example 1: Replace 2 with NA
as.na(num, na = 2)

# Example 2: Replace 2, 3, and 4 with NA
as.na(num, na = c(2, 3, 4))

# Example 3: Replace NA with 2
na.as(c(1, 3, NA, 4, 5), na = 2)

#-------------------------------------------------------------------------------
# Character vector
chr <- c("a", "b", "c", "d", "e")

# Example 4: Replace "b" with NA
as.na(chr, na = "b")

# Example 5: Replace "b", "c", and "d" with NA
as.na(chr, na = c("b", "c", "d"))

# Example 6: Replace NA with "b"
na.as(c("a", NA, "c", "d", "e"), na = "b")

#-------------------------------------------------------------------------------
# Factor
fac <- factor(c("a", "a", "b", "b", "c", "c"))

# Example 7: Replace "b" with NA
as.na(fac, na = "b")

# Example 8: Replace "b" and "c" with NA
as.na(fac, na = c("b", "c"))

# Example 9: Replace NA with "b"
na.as(factor(c("a", "a", NA, NA, "c", "c")), na = "b")

#-------------------------------------------------------------------------------
# Matrix
mat <- matrix(1:20, ncol = 4)

# Example 10: Replace 8 with NA
as.na(mat, na = 8)

# Example 11: Replace 8, 14, and 20 with NA
as.na(mat, na = c(8, 14, 20))

# Example 12: Replace NA with 2
na.as(matrix(c(1, NA, 3, 4, 5, 6), ncol = 2), na = 2)

#-------------------------------------------------------------------------------
# Array

# Example 13: Replace 1 and 10 with NA
as.na(array(1:20, dim = c(2, 3, 2)), na = c(1, 10))

#-------------------------------------------------------------------------------
# List

# Example 14:  Replace 1 with NA
as.na(list(x1 = c(1, 2, 3, 1, 2, 3),
           x2 = c(2, 1, 3, 2, 1),
           x3 = c(3, 1, 2, 3)), na = 1)

#-------------------------------------------------------------------------------
# Data frame
df <- data.frame(x1 = c(1, 2, 3),
                 x2 = c(2, 1, 3),
                 x3 = c(3, 1, 2))

# Example 15a: Replace 1 with NA
as.na(df, na = 1)

# Example 15b: Alternative specification using the 'data' argument
as.na(., data = df, na = 1)

# Example 16: Replace 1 and 3 with NA
as.na(df, na = c(1, 3))

# Example 17a: Replace 1 with NA in 'x2'
as.na(df$x2, na = 1)

# Example 17b: Alternative specification using the 'data' argument
as.na(x2, data = df, na = 1)

# Example 18: Replace 1 with NA in 'x2' and 'x3'
as.na(x2, x3, data = df, na = 1)

# Example 19: Replace 1 with NA in 'x1', 'x2', and 'x3'
as.na(x1:x3, data = df, na = 1)

# Example 20: Replace NA with -99
na.as(data.frame(x1 = c(NA, 2, 3),
                 x2 = c(2, NA, 3),
                 x3 = c(3, NA, 2)), na = -99)

# Example 2: Recode by replacing 30 with NA and then replacing NA with 3
na.as(data.frame(x1 = c(1, 2, 30),
                 x2 = c(2, 1, 30),
                 x3 = c(30, 1, 2)), na = 3, as.na = 30)