Variance of frequency distribution table (numerical variable)
S3 methods for the variance of a fdt.
Useful to estimate the variance (when the real data vector is not known) from a previous fdt.
## S3 generic var(x, ...) ## S3 methods: numerical ## Default S3 method: var(x, ...) ## S3 method for class 'fdt' var(x, ...) ## S3 method for class 'fdt.multiple' var(x, ...)
x |
A |
... |
Required to be generic. |
var.fdt calculates the value of the variance based on a known formula.
var.fdt.multiple calls var.fdtfor each variable, that is, each column of the data.frame.
var.fdt returns a numeric vector containing the value of the median of the fdt.
median.fdt.multiple returns a list, where each element is a numeric vector
containing the value of the variance of the fdt for each variable.
José Cláudio Faria
Enio G. Jelihovschi
Ivan B. Allaman
sd.fdt, mean.fdt.
mdf <- data.frame(x=rnorm(1e2,
20,
2),
y=rnorm(1e2,
30,
3),
z=rnorm(1e2,
40,
4))
head(mdf)
apply(mdf,
2,
var)
var(fdt(mdf))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.