JS中的浮点运算问题

var FloatCalculate={
//浮点数运算
floatAdd:function(arg1,arg2){
//加法运行
var r1, r2, m;
try { r1 = arg1.toString().split(".")[1].length } catch (e) { r1 = 0 }
try { r2 = arg2.toString().split(".")[1].length } catch (e) { r2 = 0 }
m = Math.pow(10, Math.max(r1, r2));
//return (arg1*m+arg2*m)/m
return ((FloatCalculate.floatMul(arg1, m) + FloatCalculate.floatMul(arg2, m)) / m);
},
floatSub:function(arg1,arg2){
//减法运行
var r1, r2, m, n;
try { r1 = arg1.toString().split(".")[1].length } catch (e) { r1 = 0 }
try { r2 = arg2.toString().split(".")[1].length } catch (e) { r2 = 0 }
m = Math.pow(10, Math.max(r1, r2));
//动态控制精度长度
n = (r1 >= r2) ? r1 : r2;
//return ((arg1*m-arg2*m)/m).toFixed(n);
return ((FloatCalculate.floatMul(arg1, m) - FloatCalculate.floatMul(arg2, m)) / m).toFixed(n);
},
floatMul:function(arg1,arg2){
//乘法运行
var m = 0, s1 = arg1.toString(), s2 = arg2.toString();
try { m += s1.split(".")[1].length } catch (e) { }
try { m += s2.split(".")[1].length } catch (e) { }
return Number(s1.replace(".", "")) * Number(s2.replace(".", "")) / Math.pow(10, m);
},
floatDiv:function(arg1,arg2){
//除法运行
var t1 = 0, t2 = 0, r1, r2;
try { t1 = arg1.toString().split(".")[1].length } catch (e) { }
try { t2 = arg2.toString().split(".")[1].length } catch (e) { }
with (Math) {
r1 = Number(arg1.toString().replace(".", ""));
r2 = Number(arg2.toString().replace(".", ""));
return FloatCalculate.floatMul((r1 / r2), pow(10, t2 - t1));
}
}
}