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| <a name="RAND-_002d_002d_002d-Real-pseudo_002drandom-number"></a> |
| <h3 class="section">8.199 <code>RAND</code> — Real pseudo-random number</h3> |
| <a name="index-RAND"></a> |
| <a name="index-random-number-generation-2"></a> |
| |
| <dl compact="compact"> |
| <dt><em>Description</em>:</dt> |
| <dd><p><code>RAND(FLAG)</code> returns a pseudo-random number from a uniform |
| distribution between 0 and 1. If <var>FLAG</var> is 0, the next number |
| in the current sequence is returned; if <var>FLAG</var> is 1, the generator |
| is restarted by <code>CALL SRAND(0)</code>; if <var>FLAG</var> has any other value, |
| it is used as a new seed with <code>SRAND</code>. |
| </p> |
| <p>This intrinsic routine is provided for backwards compatibility with |
| GNU Fortran 77. It implements a simple modulo generator as provided |
| by <code>g77</code>. For new code, one should consider the use of |
| <a href="RANDOM_005fNUMBER.html#RANDOM_005fNUMBER">RANDOM_NUMBER</a> as it implements a superior algorithm. |
| </p> |
| </dd> |
| <dt><em>Standard</em>:</dt> |
| <dd><p>GNU extension |
| </p> |
| </dd> |
| <dt><em>Class</em>:</dt> |
| <dd><p>Function |
| </p> |
| </dd> |
| <dt><em>Syntax</em>:</dt> |
| <dd><p><code>RESULT = RAND(I)</code> |
| </p> |
| </dd> |
| <dt><em>Arguments</em>:</dt> |
| <dd><table> |
| <tr><td width="15%"><var>I</var></td><td width="70%">Shall be a scalar <code>INTEGER</code> of kind 4.</td></tr> |
| </table> |
| |
| </dd> |
| <dt><em>Return value</em>:</dt> |
| <dd><p>The return value is of <code>REAL</code> type and the default kind. |
| </p> |
| </dd> |
| <dt><em>Example</em>:</dt> |
| <dd><div class="smallexample"> |
| <pre class="smallexample">program test_rand |
| integer,parameter :: seed = 86456 |
| |
| call srand(seed) |
| print *, rand(), rand(), rand(), rand() |
| print *, rand(seed), rand(), rand(), rand() |
| end program test_rand |
| </pre></div> |
| |
| </dd> |
| <dt><em>See also</em>:</dt> |
| <dd><p><a href="SRAND.html#SRAND">SRAND</a>, <a href="RANDOM_005fNUMBER.html#RANDOM_005fNUMBER">RANDOM_NUMBER</a> |
| </p> |
| </dd> |
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