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### 10.6 Random Numbers

Function: make_random_state
`make_random_state` (n)
`make_random_state` (s)
`make_random_state` (true)
`make_random_state` (false) ¶

  A random state object represents the state of the random number generator. The state comprises 627 32-bit words.

  `make_random_state (n)` returns a new random state object created from an integer seed value equal to n modulo 2^32. n may be negative.

  `make_random_state (s)` returns a copy of the random state s.

  `make_random_state (true)` returns a new random state object, using the current computer clock time as the seed.

  `make_random_state (false)` returns a copy of the current state of the random number generator.

  Categories: Random numbers ·

Function: set_random_state (s) ¶

  Copies s to the random number generator state.

  `set_random_state` always returns `done`.

  Categories: Random numbers ·

Function: random (x) ¶

  Returns a pseudorandom number. If x is an integer, `random (x)` returns an integer from 0 through `x - 1` inclusive. If x is a floating point number, `random (x)` returns a nonnegative floating point number less than x. `random` complains with an error if x is neither an integer nor a float, or if x is not positive.

  The functions `make_random_state` and `set_random_state` maintain the state of the random number generator.

  The Maxima random number generator is an implementation of the Mersenne twister MT 19937.

  Examples:

      (%i1) s1: make_random_state (654321)$

      (%i2) set_random_state (s1);
      (%o2)                         done

      (%i3) random (1000);
      (%o3)                          768

      (%i4) random (9573684);
      (%o4)                        7657880

      (%i5) random (2^75);
      (%o5)                11804491615036831636390

      (%i6) s2: make_random_state (false)$

      (%i7) random (1.0);
      (%o7)                  0.2310127244107132

      (%i8) random (10.0);
      (%o8)                   4.394553645870825

      (%i9) random (100.0);
      (%o9)                   32.28666704056853

      (%i10) set_random_state (s2);
      (%o10)                        done

      (%i11) random (1.0);
      (%o11)                 0.2310127244107132

      (%i12) random (10.0);
      (%o12)                  4.394553645870825

      (%i13) random (100.0);
      (%o13)                  32.28666704056853

  Categories: Random numbers · Numerical methods ·

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