Stata Numeric Functions

Stata supports these numeric functions in the global scope.

Dhms

Convert an date value (formatted as %td) plus an hour, minute, and second into the number of milliseconds since the Stata epoch (01jan1960 00:00:00.000`) ignoring leap seconds.

generate double datetime = dhms(dmy(day, month, year), hour, minute, second)
format date %tc

See also Cdhms, which creates returns a number that should instead be formatted as %tC because it does not ignore leap seconds.

Dmy

Convert a day, month, and year into the number of days since the Stata epoch (01jan1960 00:00:00.000).

generate long date = dmy(day, month, year)
format date %td

Hms

Convert an hour, minute, and second into the number of milliseconds since midnight ignoring leap seconds.

generate double datetime = hms(hour, minute, second)
format date %tc

See also Chms, which creates returns a number that should instead be formatted as %tC because it does not ignore leap seconds.

Mdy

Convert a month, day, and year into the number of days since the Stata epoch (01jan1960 00:00:00.000).

generate long date = mdy(month, day, year)
format date %td

Mdyhms

Convert a day, month, year, hour, minute, and second into the number of milliseconds since the Stata epoch (01jan1960 00:00:00.000) ignoring leap seconds.

generate double datetime = mdyhms(month, day, year, hour, minute, second)
format date %tc

See also Cmdyhms, which creates returns a number that should instead be formatted as %tC because it does not ignore leap seconds.

Real

RBeta

RBinomial

RCauchy

RChi2

RExponential

RGamma

RHypergeometric

RIGaussian

RLaplace

RLogistic

RNBinomial

RNormal

RPoisson

RT

RUniform

runiform(a,b) returns a random number between a and b. If no parameters are specified, the defaults of 0 and 1 are used.

Below is a demonstration for how an SRS sample can be drawn.

set seed 123456
generate double r_sampled = runiform()
sort r_sampled
generate byte sampled = _n <= 100 

The return value is a double; it will be within a + c(epsdouble) and b − c(epsdouble).

By default, runiform uses the 64-bit Mersenne Twister algorithm. Alternate algorithms are available; see set rng.

See also set seed for designing deterministic programs.

RUniformInt

RWeibull

RWeibullPH

String

Alias for strofreal.

StrOfReal

Y

Convert a year into the number of years since the Stata epoch (01jan1960 00:00:00.000).

generate int year = y(year)
format year %ty

Yh

Convert a year and half year into the number of half years since the Stata epoch (01jan1960 00:00:00.000).

generate int halfyears = yh(year, halfyear)
format halfyears %th

Ym

Convert a year and month into the number of months since the Stata epoch (01jan1960 00:00:00.000).

generate int months = y(year, month)
format months %tm

Yq

Convert a year and quarter into the number of years since the Stata epoch (01jan1960 00:00:00.000).

generate int quarters = yq(year, quarter)
format quarters %tq

Yw

Convert a year and week into the number of weeks since the Stata epoch (01jan1960 00:00:00.000).

generate int weeks = yw(year, week)
format weeks %tw

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