Discover: SidebarFilter Timeframes fix chart y max value and min value.

src/components/Discover/Filter/Timeframes.vue

@@ -63,6 +63,7 @@ export default{
       let e = 2;
       let f = this.filterTimeframe.data[1].y;
       b = (e*d - a*d - f*a - f*c) / (e - c - a)
+      b < 0 ? b = 0 : b;
       // y 軸最大值
       let ma = 9;
       let mb = this.filterTimeframe.data[8].y;
@@ -70,7 +71,8 @@ export default{
       let md = this.filterTimeframe.data[9].y;
       let me = 11;
       let mf;
-      mf = (mb*me - mb*mc -md*me + md*ma) / (ma - mc)
+      mf = (mb*me - mb*mc -md*me + md*ma) / (ma - mc);
+      mf < 0 ? mf = 0 : mf;
 
       // 添加最小值
       data.unshift({