JS implementation of random number generation algorithm sample code _javascript tips

1:

Copy Code code as follows:

var MT = [];
var index = 0;
function Initialize_generator (seed) {
Mt[0] = seed;
for (var i = 1; i < 624; i++) {
Mt[i] = 0xFFFFFFFF & (0x6c078965 * (mt[i-1) ^ (mt[i-1] >>)) + i);
}
}
function Generate_numbers () {
for (var i = 0; i < 624; i++) {
var y = (Mt[i] & 0x80000000) + (mt[(i + 1)% 624] & 0x7fffffff);
Mt[i] = mt[(i + 397)% 624] ^ (y >> 1);
if (y% 2!= 0) {
Mt[i] ^= 0x9908b0df;
}
}
}
function Extract_number () {
if (index = = 0) {
Generate_numbers ();
}
var y = Mt[index];
Y ^= (y >> 11);
Y ^= ((y << 7) & 0x9d2c5680);
Y ^= ((y <<) & 0xefc60000);
Y ^= (y >> 18);
Index = (index + 1)% 624;
return y;
}
function Mt_rand (min, max) {
Return Extract_number ()% (Max-min + 1) + min;
}
function Test () {
Initialize_generator (New Date (). GetTime ());
var test = [0, 0];
for (var i = 0; i < 100000; i++) {
Test[mt_rand (0, 1)]++;
}
return test;
}

2:

Copy Code code as follows:

The Var random=function (T1,T2,T3) {//t1 is the lower limit, the T2 is the upper limit, and the T3 is the decimal place that needs to be reserved
function Isnum (n) {
return/^\d+$/.test (n);
}
if (!t1 | | (! isnum (t1)) {t1=0;}
if (!t2 | | (! isnum (T2)) {t2=1;}
if (!t3 | | (! isnum (T3)) {t3=0;}
T3 = t3>15?15:t3; Decimal places cannot be greater than 15 bits
var ra = math.random () * (T2-T1) +t1,du=math.pow (10,T3);
RA = Math.Round (ra * du)/du;
return RA;
}