fix rand pseudo-random number generator

Fixed more documentation and code comments that referred to the old
additive 55 (a55) shuffle pseudo-random number generator.  We have
been using the subtractive 100 shuffle pseudo-random number generator
in place of the additive 55 generator for a while now.

CHANGES

@@ -170,6 +170,12 @@ The following are the changes from calc version 2.14.3.5 to date:
     Added to test 94dd, read of a number of new calc resource files
     that are not already read as a result of the calc regression test suite.
 
+    Fixed more documentation and code comments that referred to the
+    old additive 55 (a55) shuffle pseudo-random number generator.
+    We have been using the subtractive 100 shuffle pseudo-random
+    number generator in place of the additive 55 generator for a
+    while now.
+
 
 The following are the changes from calc version 2.14.3.4 to 2.14.3.5:
 

cal/README

@@ -1130,7 +1130,7 @@ randbitrun.cal
     the number and length of identical bits runs match what is expected.
     By default, run_cnt is to test the next 65536 random values.
 
-    This tests the a55 generator.
+    This tests the subtractive 100 shuffle pseudo-random number generator.
 
 
 randmprime.cal
@@ -1177,7 +1177,7 @@ randrun.cal
     64 bit values.  By default, run_cnt is to test the next 65536
     random values.
 
-    This tests the a55 generator.
+    This tests the subtractive 100 shuffle pseudo-random number generator.
 
 repeat.cal
 

cal/randbitrun.cal

@@ -1,7 +1,7 @@
 /*
- * randbitrun - check rand bit run lengths of the a55 generator
+ * randbitrun - check rand bit run lengths of the subtractive 100 shuffle generator
  *
- * Copyright (C) 1999  Landon Curt Noll
+ * Copyright (C) 1999,2023  Landon Curt Noll
  *
  * Calc is open software; you can redistribute it and/or modify it under
  * the terms of the version 2.1 of the GNU Lesser General Public License

cal/regress.cal

@@ -1737,7 +1737,7 @@ print '024: parsed test_list()';
 /*
  * test 025: define test_rand for test 15dd
  *
- * This function tests the a55 shuffle pseudo-random number generator.
+ * This function tests the subtractive 100 shuffle pseudo-random number generator.
  */
 define test_rand()
 {
@@ -3547,6 +3547,12 @@ define test_trig()
 	vrfy(tnum++ == 3407,	'3407: tnum == 3407');
 	pi = pi(1e-20);
 
+	/* test trigonometric sine */
+	vrfy(sin(0, 1e-10) == 0,
+				strcat(str(tnum++), ': sin(0, 1e-10) == 0'));
+	vrfy(sin(pi/6, 1e-10) == 0.5,
+				strcat(str(tnum++), ': sin(pi/6, 1e-10) == 0.5'));
+
 	/* test versed trigonometric sine */
 	vrfy(versin(0, 1e-10) == 0,
 				strcat(str(tnum++), ': versin(0, 1e-10) == 0'));
@@ -8297,7 +8303,7 @@ return test_list();
 
 
 /*
- * test 15dd: test the a55 shuffle pseudo-random number generator
+ * test 15dd: test the subtractive 100 shuffle pseudo-random number generator
  */
 print;
 return test_rand();

custom/c_sysinfo.c

@@ -148,9 +148,9 @@ STATIC struct infoname sys_info[] = {
      (FULL)0},
     {"HIST_SIZE", "Default history size", NULL,
      (FULL)HIST_SIZE},
-    {"INIT_J", "initial 1st walking a55 table index", NULL,
+    {"INIT_J", "initial 1st walking subtractive 100 shuffle table index", NULL,
      (FULL)INIT_J},
-    {"INIT_K", "initial 2nd walking a55 table index", NULL,
+    {"INIT_K", "initial 2nd walking subtractive 100 shuffle table index", NULL,
      (FULL)INIT_K},
     {"INODE_BITS", "inode number size in bits", NULL,
      (FULL)INODE_BITS},
@@ -222,7 +222,7 @@ STATIC struct infoname sys_info[] = {
      (FULL)SBYTES},
     {"SCNT", "length of subtractive 100 table in FULLs", NULL,
      (FULL)SCNT},
-    {"SEEDXORBITS", "low bits of a55 seed devoted to xor", NULL,
+    {"SEEDXORBITS", "low bits of subtractive 100 shuffle pseudo-random number generator seed devoted to xor", NULL,
      (FULL)SEEDXORBITS},
     {"SHALFS", "size of additive or shuffle entry in HALFs", NULL,
      (FULL)SHALFS},

func.c

@@ -997,7 +997,7 @@ f_rand(int count, NUMBER **vals)
 	/* parse args */
 	switch (count) {
 	case 0:			/* rand() == rand(2^64) */
-		/* generate an a55 random number */
+		/* generate an subtractive 100 shuffle pseudo-random number */
 		ans = qalloc();
 		zrand(SBITS, &ans->num);
 		break;
@@ -1031,7 +1031,7 @@ f_rand(int count, NUMBER **vals)
 		return NULL;
 	}
 
-	/* return the a55 random number */
+	/* return the subtractive 100 shuffle pseudo-random number */
 	return ans;
 }
 
@@ -1064,7 +1064,7 @@ f_randbit(int count, NUMBER **vals)
 	}
 
 	/*
-	 * generate an a55 random number or skip random bits
+	 * generate an subtractive 100 shuffle pseudo-random number or skip random bits
 	 */
 	ans = qalloc();
 	cnt = ztolong(vals[0]->num);
@@ -1078,7 +1078,7 @@ f_randbit(int count, NUMBER **vals)
 	}
 
 	/*
-	 * return the a55 random number
+	 * return the subtractive 100 shuffle pseudo-random number
 	 */
 	return ans;
 }
@@ -1096,14 +1096,14 @@ f_srand(int count, VALUE **vals)
 	/* parse args */
 	switch (count) {
 	case 0:
-		/* get the current a55 state */
+		/* get the current subtractive 100 shuffle pseudo-random number generator state */
 		result.v_rand = zsrand(NULL, NULL);
 		break;
 
 	case 1:
 		switch (vals[0]->v_type) {
 		case V_NUM:		/* srand(seed) */
-			/* seed a55 and return previous state */
+			/* seed subtractive 100 shuffle pseudo-random number generator and return previous state */
 			if (!qisint(vals[0]->v_num)) {
 				math_error(
 				  "srand number seed must be an integer");
@@ -1113,7 +1113,7 @@ f_srand(int count, VALUE **vals)
 			break;
 
 		case V_RAND:		/* srand(state) */
-			/* set a55 state and return previous state */
+			/* set subtractive 100 shuffle pseudo-random number generator state and return previous state */
 			result.v_rand = zsetrand(vals[0]->v_rand);
 			break;
 
@@ -1267,7 +1267,7 @@ f_srandom(int count, VALUE **vals)
 			break;
 
 		case V_RANDOM:		/* srandom(state) */
-			/* set a55 state and return previous state */
+			/* set subtractive 100 shuffle pseudo-random number generator state and return previous state */
 			result.v_random = zsetrandom(vals[0]->v_random);
 			break;