help for ^xfrac^

Tabulation using categories defined by fractions of a cut-off value -------------------------------------------------------------------

^xfrac^ varname [fweights aweights] [^if^ exp ^in^ range] , ^cut^off^(^#^)^ [ ^gp(^gpname^)^ ]

Description ----------- ^xfrac^ provides a specialized tabulation (a 'wrapper' for -tabulate-). Each valid observation is first partitioned by varname into one of a set of 20 mutually-exclusive categories, the boundaries of which are defined by 'hard-wired' fractions of a user-specified cut-off value (in the same units as varname), with fractions ranging from 0.1 through to 3.0. This classification is then tabulated and, optionally, can be retained as a new variable.

In effect ^xfrac^ provides a discrete representation of the distribution function for varname.

Example: let varname be a measure of income and the cut-off be mean income. ^xfrac^ shows the proportion of observations with income less than 10% of mean income, between 10% and 20% of mean income, between 20% and 30% of mean income, and so on (20 categories). Cumulative proportions are also shown.

Mandatory --------- ^cut^off^(^#^)^ The user must specify a value for the cut-off value (in the same units as varname).

Options ------- ^gp(^gpname^)^ creates a new categorical variable, gpname, containing categories summarising group membership.

Example ------- . ^sum x [aw=wgt]^ . ^local mean = _result(3)^ . ^xfrac x [aw=wgt], cut(`mean') gp(gpname)^

Author ------ Stephen P. Jenkins <stephenj@@essex.ac.uk> Institute for Social and Economic Research University of Essex, Colchester CO4 3SQ, U.K.

Also see -------- @pctile@, @xtile@, ^tabulate^, ^cumul^. Manual: [R] ^pctile^, [R] ^tabulate^, [R] ^cumul^. ^sumdist^ (if installed)