= Stata Numeric Functions =

Stata supports these '''numeric functions''' in the global scope.

<<TableOfContents>>

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== 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: ''e^n^''                    || ||
||`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 [[Statistics/Logit|logit function]]       || ||
||`ln(n)`            ||Natural log function                              || ||
||`logit(n)`         ||[[Statistics/Logit|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)`||

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== Date and Time Functions ==

These functions return [[Stata/DataFormats#Date_and_Datetime_Formats|date and datetime formatted values]].

||'''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 datetime from a year, month, day, hour, minute, and second   ||`%tc`              ||
||`Cmdyhms(m,d,y,h,m,s)`||Calculate a datetime 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`              ||

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== 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 [[Stata/Set#Rng|set rng]] and [[Stata/Set#Seed|set seed]].

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== See also ==

[[https://www.stata.com/manuals/fnmathematicalfunctions.pdf|Stata mathematical functions]]

[[https://www.stata.com/manuals/ddatetime.pdf|Stata datetimes]]



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