*! version 1.1.1 20jan2013

Title

dftolss -- Sample size calculation for distribution-free tolerance intervals

Syntax

dftolss , [conf(#) beta(#) r(#)]

conf(#) set confidence level of the tolerance interval; default is conf(95)

beta(#) set percentage of the population covered by the tolerance interval; default is beta(95)

r(#) set the number of blocks removed; default is r(2)

Description

dftolss computes the smallest sample size for the tolerance intervals obtained removing r(#) blocks to contain, at confidence level conf(#)%,
at least a percentage beta(#)% of the sampled population. See also dftol.

Remarks

dftolss requires that the Stata module -moremata- (Jann, 2005) be installed.

Options

conf(#) specifies the confidence level of the tolerance interval as a percentage. The default is conf(95), meaning a 95% confidence level.

beta(#) specifies the percentage of the sampled population to be contained in the tolerance interval. The default is beta(95), meaning a percentage equal to 95%.

r(#) specifies the number of blocks removed. The default is r(2), which, according to the definition of block (see Murphy, 1948) means that
the endpoints of the tolerance interval would be the smallest and largest observations of the sample. Note that for r(1), i.e. when only one
block is removed, the interval reduces to a one-sided lower (alternatively, upper) tolerance bound.

Examples

. dftolss
. dftolss, c(90) b(90)
. dftolss, c(99) b(99) r(4)

Saved results

dftolss saves the following in r():

Scalars

r(n) sample size)

Author

Ignacio López de Ullibarri

Department of Mathematics

University of A Coruña, Spain

E-mail: ilu@udc.es

References

Jann B (2005), moremata: Stata module (Mata) to provide various functions, available from http://ideas.repec.org/c/boc/bocode/s455001.html

Murphy RB (1948), Non-parametric tolerance limits, Annals of Mathematical Statistics, 19: 581-589