JS浮点数运算

//乘法函数，用来得到精确的乘法结果
//说明：javascript的乘法结果会有误差，在两个浮点数相乘的时候会比较明显。这个函数返回较为精确的乘法结果。
//调用：accMul(arg1,arg2)
//返回值：arg1乘以arg2的精确结果
function accMul(arg1,arg2)
{
var m=0,s1=arg1.toString(),s2=arg2.toString();
try{
if(s1.split(".")[1] != undefined )
m+=s1.split(".")[1].length
}catch(e){}
try{
if(s2.split(".")[1] != undefined )
m+=s2.split(".")[1].length
}catch(e){}
return Number(s1.replace(".",""))*Number(s2.replace(".",""))/Math.pow(10,m)
} //浮点数除法运算
function accDiv(arg1,arg2){
var r1=0,r2=0,m,s1=arg1.toString(),s2=arg2.toString();
try{
if(s1.split(".")[1] != undefined )
r1=s1.split(".")[1].length;
}catch(e){}
try{
if(s2.split(".")[1] != undefined )
r2=s2.split(".")[1].length;
}catch(e){}
m=Math.pow(10,Math.max(r1,r2));
return (accMul(arg1,m))/(accMul(arg2,m));
} function accAdd(arg1,arg2){
var r1=0,r2=0,m,s1=arg1.toString(),s2=arg2.toString();
try{
if(s1.split(".")[1] != undefined )
r1=s1.split(".")[1].length;
}catch(e){}
try{
if(s2.split(".")[1] != undefined )
r2=s2.split(".")[1].length;
}catch(e){}
m=Math.pow(10,Math.max(r1,r2));
return (accMul(arg1,m)+accMul(arg2,m))/m;
} function Subtr(arg1,arg2){
var r1=0,r2=0,m,n,s1=arg1.toString(),s2=arg2.toString();
try{
if(s1.split(".")[1] != undefined )
r1=s1.split(".")[1].length;
}catch(e){}
try{
if(s2.split(".")[1] != undefined )
r2=s2.split(".")[1].length;
}catch(e){}
m=Math.pow(10,Math.max(r1,r2));
//last modify by deeka
//动态控制精度长度
n=(r1>=r2)?r1:r2;
return (accMul(arg1,m)-accMul(arg2,m))/m;
}