广数980tdb车床，端面的圆弧和轴上的R4.2的圆弧怎么编程的，4.2的圆弧如果用R3的机加圆弧

function　merge(left, right){
var　result=[];
while(left.length>0 && right.length>0){
if(left[0] /*shift()方法用于把数组的第一个元素从其中删除，并返回第一个元素的值。*/
result.push(left.shift());
}else{
result.push(right.shift());
}
}
return　result.concat(left).concat(right);
}
function　mergeSort(items){
if(items.length == 1){
return　items;
}
var　middle = Math.floor(items.length/2),
left = items.slice(0, middle),
right = items.slice(middle);
return　merge(mergeSort(left), mergeSort(right));
}