Usa una mapreduce per calcolare in minimo e il massino di un dato valore per il progetto meteo.marcoberri.it

MaxMinData.js

/***

Extract max a min data from rawtable of extracting data from La crosse WS1640


project: http://meteo.marcoberri.it

**/

var dbOne = db.getSisterDB('mbmeteolacrosse');

var periods = ['Hour','Day', 'Month', 'Year'];
	for (var p in periods) {
		var period =periods[p];

		var fields = ['T1', 'H1', 'PRESS','WC', 'WS'];
		for (var f in fields) {
	
			var fieldName = fields[f];

			var KEYS = {FIELD: fieldName, PERIOD: period};

			var map = function(){

				var periodFunction = "";		
				var day = (this.ts.getDate() <10 ? "0" + this.ts.getDate() : this.ts.getDate());
     				var month = (this.ts.getMonth()+1 < 10 ? "0" + (this.ts.getMonth()+1) : (this.ts.getMonth()+1));

     				if(KEYS.PERIOD == 'Hour')
             				periodFunction = (this.ts.getFullYear() + "-" + month + "-" + day + ":"+ (this.ts.getHours()<10 ? "0"+this.ts.getHours() : this.ts.getHours()) );
				if(KEYS.PERIOD == 'Day')
					periodFunction = (this.ts.getFullYear() + "-" + month + "-" + day );		
				if(KEYS.PERIOD == 'Month')
					periodFunction = (this.ts.getFullYear() + "-" + month);		
				if(KEYS.PERIOD == 'Year')
					periodFunction = this.ts.getFullYear();		


				emit(periodFunction, this[KEYS.FIELD]); 
			};

			var reduceMin = function(date, values){  
						var min = values[0];    
						values.forEach(
							function(val) {    
								if(!isNaN(val) && val < min) 
									min = val; 
							}
						);    
						return min 
					};

			var reduceMax = function(date, values){  
						var max = values[0];    
						values.forEach(
								function(val) {    
									if(!isNaN(val) && val > max) 
										max = val; 
								}
						);    
						return max 
					};


			var c = dbOne.rawdata.mapReduce(map,reduceMin,{out:{inline:1}, scope : {KEYS:KEYS}}).results;
	
			var fname = fieldName + 'Min' + period;

			for(var i=0;i<c.length;i++){
				var updateDate = {};
				updateDate["$set"] = {}
				updateDate["$set"][fname] = c[i].value;
 				updateDate["$set"]['ts'] = c[i]._id;
				dbOne.maxmindata.update({'ts' : c[i]._id},updateDate,{'upsert':true});
			};

			var c = dbOne.rawdata.mapReduce(map,reduceMax,{out:{inline:1}, scope : {KEYS:KEYS}}).results;
	
			var fname = fieldName + 'Max' + period;

			for(var i=0;i<c.length;i++){
				var updateDate = {};
				updateDate["$set"] = {}
				updateDate["$set"][fname] = c[i].value;
 				updateDate["$set"]['ts'] = c[i]._id;
				dbOne.maxmindata.update({'ts' : c[i]._id},updateDate,{'upsert':true});
			};

			print(fieldName + " - for:" + period +" --> ok");

		};
	};