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- Function:
**random***n state* - Function:
**random***n* -
`n`must be an exact positive integer.`random`

returns an exact integer between zero (inclusive) and`n`(exclusive). The values returned by`random`

are uniformly distributed from 0 to`n`.The optional argument

`state`must be of the type returned by`(seed->random-state)`

or`(make-random-state)`

. It defaults to the value of the variable`*random-state*`

. This object is used to maintain the state of the pseudo-random-number generator and is altered as a side effect of calls to`random`

.

- Variable:
***random-state*** Holds a data structure that encodes the internal state of the random-number generator that

`random`

uses by default. The nature of this data structure is implementation-dependent. It may be printed out and successfully read back in, but may or may not function correctly as a random-number state object in another implementation.

- Function:
**copy-random-state***state* -
Returns a new copy of argument

`state`.

- Function:
**copy-random-state** Returns a new copy of

`*random-state*`

.

- Function:
**seed->random-state***seed* -
Returns a new object of type suitable for use as the value of the variable

`*random-state*`

or as a second argument to`random`

. The number or string`seed`is used to initialize the state. If`seed->random-state`

is called twice with arguments which are`equal?`

, then the returned data structures will be`equal?`

. Calling`seed->random-state`

with unequal arguments will nearly always return unequal states.

- Function:
**make-random-state** - Function:
**make-random-state***obj* Returns a new object of type suitable for use as the value of the variable

`*random-state*`

or as a second argument to`random`

. If the optional argument`obj`is given, it should be a printable Scheme object; the first 50 characters of its printed representation will be used as the seed. Otherwise the value of`*random-state*`

is used as the seed.

Next: Inexact Random Numbers, Previous: Random Numbers, Up: Random Numbers [Contents][Index]