API:RNG::next - Revision history

Bruce Pascoe: Improving headings some more

2017-08-10T03:53:10Z

Improving headings some more

Bruce Pascoe: Reorganize page, add sub-headings for organization, add description

2017-08-09T15:45:10Z

Reorganize page, add sub-headings for organization, add description

Bruce Pascoe: New page: RNG::next()

2017-08-08T14:55:58Z

New page: RNG::next()

New page

{{DISPLAYTITLE:RNG::next()}}

<tt>'''RNG::next()'''</tt> generates a pseudorandom floating-point number between 0.0 and 1.0 (exclusive).

==== Usage ====
''number'' = ''rng_object''.'''next'''();

__TOC__

== Example ==

/*
* Shuffle a list of numbers (Fisher-Yates)
*/

let numbers = [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]
let rnGen = new RNG();
for (let i = numbers.length - 1; i > 0; --i) {
let j = Math.floor(rnGen.next() * (i + 1)); // integer, [0,i]
let orig_i = numbers[i];
numbers[i] = numbers[j];
numbers[j] = orig_i;
}

[[Category:Sphere 2 API]]

@@ Line 1: / Line 1: @@
 {{DISPLAYTITLE:RNG::next()}}
-The <tt>'''RNG::next()'''</tt> method returns a random floating-point number in the range <tt>[0,1)</tt>.
+The <tt>'''RNG::next()'''</tt> method generates a random floating-point number in the range <tt>[0,1)</tt>.
 === Usage ===
@@ Line 12: / Line 12: @@
 === Description ===
-<tt>'''RNG::next()'''</tt> generates a pseudorandom floating-point value greater than or equal to 0 but less than 1 and returns the value so generated.  The value this function returns is entirely determined by the current state of the <tt>RNG</tt> instance before the call (see <tt>[[API:RNG::state|RNG::state]]</tt>).  After calling this function, the state is advanced so a different value will be generated next time.  If you save the state before <tt>RNG.next()</tt>, then restore it afterwards and call <tt>RNG.next()</tt> again, the same value will be generated.
+<tt>'''RNG::next()'''</tt> generates a pseudorandom floating-point number greater than or equal to 0 but less than 1 and returns the value generated.  The number generated is entirely determined by the current state of the <tt>RNG</tt> instance before the call (see <tt>[[API:RNG::state|RNG::state]]</tt>).  After calling this function, the state is advanced so a different value will be generated next time.  Therefore if you save the RNG's state before calling <tt>RNG.next()</tt>, then restore it afterwards and call <tt>RNG.next()</tt> again, the same value will be returned.
-=== Examples ===
+=== Parameters ===
-==== Shuffle items in an array ====
+This method has no parameters.
   let items = [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]
   let rnGen = new RNG();
   for (let i = items.length - 1; i > 0; --i) {
@@ Line 26: / Line 35: @@
       items[j] = orig_i;
+  }
 [[Category:Sphere 2 API]]

@@ Line 1: / Line 1: @@
 {{DISPLAYTITLE:RNG::next()}}
-<tt>'''RNG::next()'''</tt> generates a pseudorandom floating-point number between 0.0 and 1.0 (exclusive).
+The <tt>'''RNG::next()'''</tt> method returns a random floating-point number in the range <tt>[0,1)</tt>.
-==== Usage ====
+=== Usage ===
   ''number'' = ''rng_object''.'''next'''();
 __TOC__
-== Example ==
+== API Information ==
-  /*
+=== Description ===
-  *  Shuffle a list of numbers (Fisher-Yates)
-  */
+<tt>'''RNG::next()'''</tt> generates a pseudorandom floating-point value greater than or equal to 0 but less than 1 and returns the value so generated.  The value this function returns is entirely determined by the current state of the <tt>RNG</tt> instance before the call (see <tt>[[API:RNG::state|RNG::state]]</tt>).  After calling this function, the state is advanced so a different value will be generated next time.  If you save the state before <tt>RNG.next()</tt>, then restore it afterwards and call <tt>RNG.next()</tt> again, the same value will be generated.
-−
-  let numbers = [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]
+=== Examples ===
   let rnGen = new RNG();
-  for (let i = numbers.length - 1; i > 0; --i) {
+  for (let i = items.length - 1; i > 0; --i) {
-      let j = Math.floor(rnGen.next() * (i + 1));  // integer, [0,i]
+      let j = Math.floor(rnGen.next() * (i + 1));  // discrete [0,i]
-      let orig_i = numbers[i];
+      let orig_i = items[i];
-      numbers[i] = numbers[j];
+      items[i] = items[j];
-      numbers[j] = orig_i;
+      items[j] = orig_i;
+  }
 [[Category:Sphere 2 API]]