IQR {stats} | R Documentation |
computes interquartile range of the x
values.
IQR(x, na.rm = FALSE, type = 7)
x |
a numeric vector. |
na.rm |
logical. Should missing values be removed? |
type |
an integer selecting one of the many quantile algorithms,
see |
Note that this function computes the quartiles using the
quantile
function rather than following
Tukey's recommendations,
i.e., IQR(x) = quantile(x, 3/4) - quantile(x, 1/4)
.
For normally N(m,1)
distributed X
, the expected value of
IQR(X)
is 2*qnorm(3/4) = 1.3490
, i.e., for a normal-consistent
estimate of the standard deviation, use IQR(x) / 1.349
.
Tukey, J. W. (1977). Exploratory Data Analysis. Reading: Addison-Wesley.
fivenum
, mad
which is more robust,
range
, quantile
.
IQR(rivers)