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| Stata supports these '''numeric functions''' in the global scope. |
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| == Random Number Functions == === Runiform === |
== Abs == ---- == Ceil == ---- == CLogLog == ---- == Comb == ---- == 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. ---- == DiGamma == ---- == 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 }}} ---- == Exp == ---- == ExpM1 == ---- == Floor == ---- == 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. ---- == Int == ---- == InvCLogLog == ---- == InvLogit == ---- == Ln == ---- == Ln1M == ---- == Ln1P == ---- == LnFactorial == ---- == LnGamma == ---- == Log == ---- == Log10 == ---- == Log1M == ---- == Log1P == ---- == Logit == ---- == Max == ---- == 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. ---- == Min == ---- == Mod == ---- == Real == ---- == RBeta == ---- == RBinomial == ---- == RCauchy == ---- == RChi2 == ---- == RelDif == ---- == RExponential == ---- == RGamma == ---- == RHypergeometric == ---- == RIGaussian == ---- == RLaplace == ---- == RLogistic == ---- == RNBinomial == ----- == RNormal == ---- == Round == ---- == RPoisson == ---- == RT == ---- == RUniform == |
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Below is a demonstration for how an [[SurveySamples#Sampling_Methods|SRS sample]] can be drawn. |
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| }}} The return value is a [[Stata/Types|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`'''. === Set Rng === To use an alternate random number generation algorithm, set the rng value to something other than `default`. {{{ set rng default }}} Possible values include... * `mt64` (64-bit Mersenne Twister) * `mt64s` (stream algorithm based on the 64-bit Mersenne Twister) * `kiss32` (32-bit keep it simple stupid) In Stata 14, the default flipped from `kiss32` to `mt64`. === Set Seed === To make random number generation reproducible, set a seed value. {{{ set seed 42 }}} A seed value must be an integer, non-negative, and no greater than 2^31^ − 1. |
sort r_sampled generate byte sampled = _n <= 100 }}} The return value is a [[Stata/DataTypes|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 [[Stata/Set#Rng|set rng]]. See also [[Stata/Set#Seed|set seed]] for designing deterministic programs. ---- == RUniformInt == ---- == RWeibull == ---- == RWeibullPH == ---- == Sign == ---- == SqRt == ---- == String == Alias for `strofreal`. ---- == StrOfReal == ---- == Sum == ---- == TriGamma == ---- == Trunc == ---- == 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 }}} |
Stata Numeric Functions
Stata supports these numeric functions in the global scope.
Contents
-
Stata Numeric Functions
- Abs
- Ceil
- CLogLog
- Comb
- Dhms
- DiGamma
- Dmy
- Exp
- ExpM1
- Floor
- Hms
- Int
- InvCLogLog
- InvLogit
- Ln
- Ln1M
- Ln1P
- LnFactorial
- LnGamma
- Log
- Log10
- Log1M
- Log1P
- Logit
- Max
- Mdy
- Mdyhms
- Min
- Mod
- Real
- RBeta
- RBinomial
- RCauchy
- RChi2
- RelDif
- RExponential
- RGamma
- RHypergeometric
- RIGaussian
- RLaplace
- RLogistic
- RNBinomial
- RNormal
- Round
- RPoisson
- RT
- RUniform
- RUniformInt
- RWeibull
- RWeibullPH
- Sign
- SqRt
- String
- StrOfReal
- Sum
- TriGamma
- Trunc
- Y
- Yh
- Ym
- Yq
- Yw
Abs
Ceil
CLogLog
Comb
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.
DiGamma
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
Exp
ExpM1
Floor
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.
Int
InvCLogLog
InvLogit
Ln
Ln1M
Ln1P
LnFactorial
LnGamma
Log
Log10
Log1M
Log1P
Logit
Max
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.
Min
Mod
Real
RBeta
RBinomial
RCauchy
RChi2
RelDif
RExponential
RGamma
RHypergeometric
RIGaussian
RLaplace
RLogistic
RNBinomial
RNormal
Round
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
Sign
SqRt
String
Alias for strofreal.
StrOfReal
Sum
TriGamma
Trunc
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