Stata Numeric Functions

Stata supports these numeric functions in the global scope.


General Purpose

Function Name

Meaning

Example

abs(n)

Absolute value function

ceil(n)

Round up to an integer

comb(n,k)

[[Statistics/Combinations|Combinatorial function

exp(n)

Exponential function: en

expm1(n)

High precision implementation of exp(n)-1

floor(n)

Round down to an integer

int(n)

Round towards 0 to an integer

-5 = int(-5.8)

invlogit(n)

Inverse logit function

ln(n)

Natural log function

logit(n)

Logit function

ln1m(n)

High precision implementation of ln(n-1)

ln1p(n)

High precision implementation of ln(n+1)

max(n,...)

Returns the value of the greatest argument

5 = max(1,.,5)

mix(n,...)

Returns the value of the least argument

1 = min(1,.,5)

mod(x,y)

x modulo y

real(s)

Convert string s into a real number

round(n)

Round to the nearest integer

round(n,p)

Round to the nearest value for a given precision

sign(n)

Returns -1 if n<0, 0 if n=0, and 1 if n>0

sqrt(n)

Square root function

string(n)

Convert numeric value n into a string

strofreal(n)

Convert numeric value n into a string

sum(x)

Running sum of variable x

trunc(n)

Round towards 0 to an integer

-5 = trunc(-5.8)


Date and Time Functions

These are largely defined in terms of dates and times, which have a standardized meaning. They count days (seconds) from the Stata epoch: 01jan1960 00:00:00.000.

Function Name

Meaning

Output Format

dhms(d,h,m,s)

Attach hour, minute, and second data to a date

%tc

Cdhms(d,h,m,s)

Attach hour, minute, and second data to a date

%tC

dmy(d,m,y)

Calculate a date from a day, month, and year

%td

hms(h,m,s)

Calculate a time from an hour, minute, and second

%tc

Chms(h,m,s)

Calculate a time from an hour, minute, and second

%tC

mdy(m,d,y)

Calculate a date from a month, day, and year

%td

mdyhms(m,d,y,h,m,s)

Calculate a time from a year, month, day, hour, minute, and second

%tc

Cmdyhms(m,d,y,h,m,s)

Calculate a time from a year, month, day, hour, minute, and second

%tC

y(y)

Convert a numeric year into the number of years since the epoch

%ty

yh(y,h)

Convert a year and halfyear into the number of half years since the epoch

%th

ym(y,m)

Convert a year and month into the number of months since the epoch

%tm

yq(y,q)

Convert a year and quarter into the number of quarters since the epoch

%tq

yw(y,w)

Convert a year and week into the number of weeks since the epoch

%tw


Statistical Functions

Function Name

Meaning

Example

invnormal(p)

Inverse cumulative standard normal distribution

1.959964 = invnormal(1-0.05/2)

normal(z)

Cumulative standard normal distribution

.9750021 = normal(1.96)

runiform()

Random number from uniform distribution from 0 to 1

runiform(a,b)

Random number from uniform distribution from a to b

Of relevance to random values: see set rng and set seed.


See also

Stata mathematical functions

Stata datetimes


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