Map reduce problem

map reduce

map function:

function(doc) {
    if(doc.symbol.lastIndexOf("HFF") == 0){    
    emit(doc.symbol,{last_update:doc.last_updatedutc,symbol:doc.symbol,last_yield:doc.last_yield});
    }
}

View output:

{"total_rows":19,"offset":0,"rows":[
{"id":"HFF1502242012-02-22 15:59:59","key":"HFF150224","value":{"last_update":"2012-02-22 15:59:59.00","symbol":"HFF150224","last_yield":0.01094398}},
{"id":"HFF1502242012-02-22 18:04:10.4398","key":"HFF150224","value":{"last_update":"2012-02-22 18:04:10.43","symbol":"HFF150224","last_yield":0.01094398}},
{"id":"HFF1502242012-02-23 09:21:04.5628","key":"HFF150224","value":{"last_update":"2012-02-23 09:21:04.56","symbol":"HFF150224","last_yield":0.01093423}}
]}

Reduce function:

function(keys, values) {
        result = [];
        keys.foreach(key,idx,arg){
	    var k = {yield:0,date:new Date(1, 1, 1, 0, 0, 0, 0)}
            values.foreach(val,i,a){
 	        if(val.symbol == key && val.last_update > k.date){
	            k.date = val.last_update;
 		    k.yield = val.yield;
	        }
            }
            result.push({key, k});
        }
        return result;
}

result (reduce=true&group=true):

{"rows":[
{"key":"HFF150224","value":null}]}