#include "MusimatChapter9.h"Go to the source code of this file.
Functions | |
| MusimatChapter9Section (C091204a) | |
| IntegerList | randomRow (Integer N) |
| Static Void | para1 () |
| MusimatChapter9Section | ( | C091204a | ) |
Definition at line 2 of file C091204a.cpp.
References para1().
{
Print("*** Sampling without Replacement ***");
/*****************************************************************************
Sampling without Replacement
We can generate a randomly selected 12-tone row, for example,
by putting 12 balls in an urn, each marked with one of the chromatic pitch classes, and draw them out
one at a time without replacement, thereby guaranteeing that no pitch class is chosen more than once.
Random(0, 11) returns a random integer between 0 and 11 with equal probability. But it could
return the same value multiple times, so we must keep track of which pitch classes have been cho-
sen to ensure that it eventually picks one of each. This function takes one argument, N, determining
the length of the row.
*****************************************************************************/
para1(); // Step into this function to continue.
}
| Static Void para1 | ( | ) |
Definition at line 43 of file C091204a.cpp.
References randomRow().
{
/*****************************************************************************
Note that the second loop keeps repeating over and over until Random() has finally selected
all N pitch classes. It then returns the newly created 12-tone row in M.
*****************************************************************************/
Print("*** Random Row ***");
Print("A random row:", randomRow(12));
/*****************************************************************************
Here is an example row created by randomRow():
{0, 6, 2, 9, 7, 5, 4, 10, 8, 3, 1, 11};
Every pitch class is represented exactly once.
*****************************************************************************/
}
| IntegerList randomRow | ( | Integer | N ) |
Definition at line 20 of file C091204a.cpp.
{
IntegerList L; // keep track of pitches chosen so far
IntegerList M; // used to build up random 12-tone row
Integer i;
// set all list elements to zero, which means "unused"
For (i = 0; i < N; i = i + 1) {
L[i] = 0;
}
// build up M, marking off elements in L when they are chosen
i = 0;
While (i < N) {
Integer x = Random(0, N - 1); // returns integer random value
If (L[x] == 0) { // hasn't been chosen yet?
L[x] = 1; // mark it "used"
M[i] = x; // save result
i = i + 1; // increment control variable
}
}
Return(M);
}
1.7.2