怎樣獲得第一個符合條件的Barindex()呢?

chunwaihome

我用explorer,篩選一年的data,它顯示五到六個的結果
我想問我怎樣獲得第一個符合條件的Barindex()呢?
想了很久都找不到答案

fastMa = MA(Close,30);
slowMA = MA(Close,50);
longMA = MA(Close,100);

buy=  Cross(fastMa,LongMA) ;
Sell =  Cross(slowMA,fastMA) ;

addcolumn(buy,"buy");

amibroker

buybar=barcount-1-barssince(buy);
or
buybar=barcount-1-valuewhen(buy,barindex(),1);