Stata Numeric Functions

Contents

  1. Stata Numeric Functions
    1. Random Number Functions
      1. Runiform
      2. Set Rng
      3. Set Seed

Random Number Functions

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. 

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.

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...

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 231 − 1.

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