Javascript natural taxonomy algorithm implementation code

  • 2020-03-26 21:26:43
  • OfStack


<!doctype html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=7, IE=9, IE=10">
<meta name="viewport"
content="initial-scale=1, maximum-scale=1,user-scalable=no">
<title> Natural classification algorithm </title>
<script>
function getJenksBreaks(data,numclass) {
function sortNumber(a,b)//In javascript, the sort method of Array, you have to use this function, otherwise it's not sorted by number
{
return a - b
}
// int numclass;
var numdata = data.length;
data.sort(sortNumber); //First order
var mat1=new Array();
var mat2=new Array();
var st=new Array();
for (var j = 0; j <= numdata; j++){
mat1[j]=new Array();
mat2[j]=new Array();
st[j]=0;
for(var i=0;i<=numclass;i++){
mat1[j][i]=0;
mat2[j][i]=0;
}
}
for (var i = 1; i <= numclass; i++) {
mat1[1][i] = 1;
mat2[1][i] = 0;
for (var j = 2; j <= numdata; j++){
mat2[j][i]=Number.MAX_VALUE;
}
}
var v=0;
for (var l = 2; l <= numdata; l++) {
var s1=0;
var s2=0;
var w=0;
var i3=0;
for (var m = 1; m <= l; m++) {
i3 = l - m + 1;
var val=parseInt(data[i3-1]);
s2 += val * val;
s1 += val;
w++;
v = s2 - (s1 * s1) / w;
var i4 = i3 - 1;
if (i4 != 0) {
for (var j = 2; j <= numclass; j++) {
if (mat2[l][j] >= (v + mat2[i4][j - 1])) {
mat1[l][j] = i3;
mat2[l][j] = v + mat2[i4][j - 1];
if(l==200&&j==5) alert("l="+200+",j="+5+";mat2[200][5]="+mat1[l][j]+"i3="+i3);
}
}
}
}
mat1[l][1] = 1;
mat2[l][1] = v;
}
var k = numdata;
var kclass=new Array();

kclass[numclass - 1] = parseInt(data[data.length-1]);

for (var j = numclass; j >= 2; j--) {
var id = parseInt(mat1[k][j]) - 2;
kclass[j - 2] = parseInt( data[id]);
k = parseInt( mat1[k][j] - 1);
}
return kclass;
}
function doit(){
var data = new Array( 9, 9, 9, 9, 8, 1, 9, 7, 6, 7, 10, 7, 7, 8, 5, 7, 8, 2,
6, 6, 9, 10, 2, 2, 3, 9, 9, 1, 9, 1, 6, 7, 1, 9, 6, 5, 2, 8, 6,
6, 6, 4, 1, 4, 10, 9, 6, 9, 9, 7, 10, 9, 6, 6, 6, 9, 3, 2, 5,
10, 3, 9, 6, 1, 2, 1, 2, 7, 5, 2, 6, 6, 2, 7, 9, 9, 5, 4, 6, 4,
1, 1, 5, 1, 4, 4, 2, 6, 9, 7, 3, 10, 4, 4, 9, 5, 5, 3, 5, 3,
161, 136, 22, 113, 48, 114, 166, 33, 159, 182, 135, 22, 174,
191, 60, 176, 1, 155, 62, 142, 185, 84, 140, 27, 111, 176, 189,
24, 60, 29, 139, 20, 70, 172, 90, 120, 121, 173, 57, 138, 86,
180, 143, 155, 35, 10, 136, 158, 26, 29, 136, 97, 193, 194,
104, 147, 182, 44, 84, 139, 176, 16, 130, 168, 109, 182, 87,
78, 115, 75, 32, 88, 131, 168, 89, 25, 160, 60, 72, 92, 129,
159, 99, 5, 192, 6, 53, 15, 62, 176, 73, 129, 128, 34, 190, 95,
19, 19, 196, 30 );

//Collections.sort(list);
var text=document.getElementById("text");
text.value="";
var grade = getJenksBreaks(data, 5);
for (var i = 0; i < grade.length; i++) 
text.value=text.value+grade[i]+",";
}
</script>
</head>
<body >
<button type="button"onclick="doit()"> Natural classification </button>
<input id="text"></input>
</body>
</html>


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