Round - Revision history

40166222 at 16:45, 18 July 2018

2018-07-18T16:45:20Z

← Older revision		Revision as of 16:45, 18 July 2018
Line 13:		Line 13:
	function () {		function () {
	emit(this.name, this.population);		emit(this.name, this.population);
	},		},
	function (key, values) {		function (key, values) {
	return values;		return values;

40166222 at 16:44, 18 July 2018

2018-07-18T16:44:59Z

← Older revision		Revision as of 16:44, 18 July 2018
Line 9:		Line 9:
	==MapReduce==		==MapReduce==
	<div class="q nonum" data-lang="mongo">		<div class="q nonum" data-lang="mongo">
	<pre class="def">		<pre class="def"><nowiki>
	db.world.mapReduce(		db.world.mapReduce(
	function(){		function () {
	emit(this.name, this.population);		emit(this.name, this.population);
	},		},
	function(key, values){		function (key, values) {
	return values;		return values;
	},		},
	{		{
	finalize: function(key,values){		finalize: function (key,values) {
	return {		return {
	"population": values,		"population": values,
	"population in millions": Math.round(values/1000000)		"population in millions": Math.round(values / 1000000)
	};		};
	},		},
Line 27:		Line 27:
	query: {"name": "United Kingdom"}		query: {"name": "United Kingdom"}
	}		}
	)		);</nowiki></pre>
	</pre>
	</div>		</div>

	==Aggregate==		==Aggregate==
	<div class="q nonum" data-lang="mongo">		<div class="q nonum" data-lang="mongo">
	<pre class="def">		<pre class="def"><nowiki>
	db.world.aggregate([		db.world.aggregate([
	{"$match": {"name": "United Kingdom"}},		{"$match": {"name": "United Kingdom"}},
	{"$project":{		{"$project": {
	"_id": 1,		"_id": 1,
	"name": 1,		"name": 1,
	"population":{"$divide": ["$population", 1000000]}		"population": {"$divide": ["$population", 1000000]}
	}},		}},
	{"$project":{		{"$project": {
	"_id": 0,		"_id": 0,
	"name": 1,		"name": 1,
	"population in millions": '$population',		"population in millions": '$population',
	"population in millions (floored)":{ "$floor": "$population"},		"population in millions (floored)": {"$floor": "$population"},
	"population in millions (ceiling)":{ "$ceil": "$population"},		"population in millions (ceiling)": {"$ceil": "$population"},
	"population in millions (truncated)":{ "$trunc": "$population"},		"population in millions (truncated)": {"$trunc": "$population"},
	"population in millions (1dp with multiply / mod)":{		"population in millions (1dp with multiply / mod)":{
	"$divide":[		"$divide":[
	{"$subtract":[		{"$subtract":[
	{"$multiply": ['$population', 100]},		{"$multiply": ['$population', 100]},
	{"$mod": [{"$multiply": ['$population',100]}, 1]}		{"$mod": [{"$multiply": ['$population', 100]}, 1]}
	]},		]},
	100		100
Line 58:		Line 57:
	}		}
	}}		}}
	]).pretty()		]).pretty();</nowiki></pre>
	</pre>
	</div>		</div>

40166222 at 04:43, 6 April 2018

2018-04-06T04:43:52Z

← Older revision		Revision as of 04:43, 6 April 2018
Line 44:		Line 44:
	"_id": 0,		"_id": 0,
	"name": 1,		"name": 1,
	"population": '$population',		"population in millions": '$population',
	"population in millions (floored)":{ "$floor": "$population"},		"population in millions (floored)":{ "$floor": "$population"},
	"population in millions (ceiling)":{ "$ceil": "$population"},		"population in millions (ceiling)":{ "$ceil": "$population"},

40166222: Update for 3.6

2018-04-06T03:00:04Z

Update for 3.6

← Older revision		Revision as of 03:00, 6 April 2018
Line 1:		Line 1:
	{{TopTenTips}}		{{TopTenTips}}
	<div style="min-height:25em">		<div style="min-height:25em">
	Rounding is easy inside a <code>MapReduce</code> as it is possible to use the <code>Math</code> object provided by JavaScript.<br/>		There are various ways of rounding in MongoDB.<br/>
			Rounding is easy inside of a <code>MapReduce</code> as it is possible to use the <code>Math</code> object provided by JavaScript.<br/>
	More information on <code>Math</code> can be found [https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Math here].<br/><br/>		More information on <code>Math</code> can be found [https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Math here].<br/><br/>
	~~At the time of writing~~ the <code>aggregation()</code> method has no rounding functions, though it is still doable with <code>$mod</code> and <code>$multiply</code>, as shown [http://www.kamsky.org/stupid-tricks-with-mongodb/rounding-numbers-in-aggregation-framework here] by the lead project manager at MongoDB.<br/>		In MongoDB versions prior to 3.2 the <code>aggregation()</code> method has no rounding functions, though it is still doable with <code>$mod</code> and <code>$multiply</code>, as shown [http://www.kamsky.org/stupid-tricks-with-mongodb/rounding-numbers-in-aggregation-framework here] by the lead project manager at MongoDB.<br/>
			As of MongoDB 3.2, it is possible to round up, down, and truncate via <code>$ceil</code>, <code>$floor,</code> and <code>$trunc</code> respectively.
	</div>		</div>
	==MapReduce==		==MapReduce==
Line 43:		Line 45:
	"name": 1,		"name": 1,
	"population": '$population',		"population": '$population',
	"population in millions":{		"population in millions (floored)":{ "$floor": "$population"},
			"population in millions (ceiling)":{ "$ceil": "$population"},
			"population in millions (truncated)":{ "$trunc": "$population"},
			"population in millions (1dp with multiply / mod)":{
	"$divide":[		"$divide":[
	{"$subtract":[		{"$subtract":[

40166222: Update to mongo shell.

2018-04-06T02:46:11Z

Update to mongo shell.

← Older revision		Revision as of 02:46, 6 April 2018
Line 1:		Line 1:
	~~<pre class=setup>~~
	~~#ENCODING~~
	~~import io~~
	~~import sys~~
	~~sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-16')~~
	~~#MONGO~~
	~~from pymongo import MongoClient~~
	~~client = MongoClient()~~
	~~client.progzoo.authenticate('scott','tiger')~~
	~~db = client['progzoo']~~
	~~#PRETTY~~
	~~import pprint~~
	~~pp = pprint.PrettyPrinter(indent=4)~~
	~~#CODE~~
	~~from bson.code import Code~~
	~~</pre>~~
	{{TopTenTips}}		{{TopTenTips}}
	<div style="min-height:25em">		<div style="min-height:25em">
	Rounding is easy inside a <code>MapReduce</code> as it is possible to use the <code>Math</code> object provided by JavaScript.<br/>		Rounding is easy inside a <code>MapReduce</code> as it is possible to use the <code>Math</code> object provided by JavaScript.<br/>
	More information on <code>Math</code> can be found [https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Math here].<br/><br/>		More information on <code>Math</code> can be found [https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Math here].<br/><br/>
	At the time of writing the <code>aggregation()</code> method has no rounding functions, though it is still doable with <code>$mod</code> and <code>$multiply</code>, as shown [http://www.kamsky.org/stupid-tricks-with-mongodb/rounding-numbers-in-aggregation-framework here] by the lead project manager at MongoDB<br/>.		At the time of writing the <code>aggregation()</code> method has no rounding functions, though it is still doable with <code>$mod</code> and <code>$multiply</code>, as shown [http://www.kamsky.org/stupid-tricks-with-mongodb/rounding-numbers-in-aggregation-framework here] by the lead project manager at MongoDB.<br/>
	</div>		</div>
	==MapReduce==		==MapReduce==
	<div class="q nonum" data-lang="~~py3~~">		<div class="q nonum" data-lang="mongo">
	<pre class=def>		<pre class="def">
	~~temp =~~ db.world.~~map_reduce~~(		db.world.mapReduce(
	~~query={"name":"United Kingdom"},~~		function(){
	~~map=Code("~~function(){emit(this.name, this.population)}"),		emit(this.name, this.population);
	~~reduce=Code("~~function(key, values){return values}"),		},
	finalize~~=Code("~~function(key,values){return Math.round(values/1000000)}"),		function(key, values){
	out={"inline":1},		return values;
	)		},
	~~pp.pprint(~~		{
	~~temp[~~"~~results~~"]		finalize: function(key,values){
			return {
			"population": values,
			"population in millions": Math.round(values/1000000)
			};
			},
			out: {inline: 1},
			query: {"name": "United Kingdom"}
			}
	)		)
	</pre>		</pre>
Line 38:		Line 30:

	==Aggregate==		==Aggregate==
	<div class="q nonum" data-lang="~~py3~~">		<div class="q nonum" data-lang="mongo">
	<pre class=def>		<pre class="def">
	~~pp.pprint(list(~~		db.world.aggregate([
	db.world.aggregate([		{"$match": {"name": "United Kingdom"}},
	{"$match": {"name":"United Kingdom"}},		{"$project":{
	{"$project":{		"_id": 1,
	"_id":1, "name":1, "population":{"$divide":["$population",1000000]}		"name": 1,
	}},		"population":{"$divide": ["$population", 1000000]}
	{"$project":{		}},
	"_id":0, "name":1, "population in millions":{"$divide":[		{"$project":{
	{"$subtract":[		"_id": 0,
	{"$multiply":['$population',100]},		"name": 1,
	{"$mod":[{"$multiply":['$population',100]}, 1]}		"population": '$population',
	]},100		"population in millions":{
	]}		"$divide":[
	}}		{"$subtract":[
	])		{"$multiply": ['$population', 100]},
	))		{"$mod": [{"$multiply": ['$population',100]}, 1]}
			]},
			100
			]
			}
			}}
			]).pretty()
	</pre>		</pre>
	</div>		</div>

40166222 at 13:31, 28 July 2015

2015-07-28T13:31:20Z

← Older revision		Revision as of 13:31, 28 July 2015
Line 21:		Line 21:
	At the time of writing the <code>aggregation()</code> method has no rounding functions, though it is still doable with <code>$mod</code> and <code>$multiply</code>, as shown [http://www.kamsky.org/stupid-tricks-with-mongodb/rounding-numbers-in-aggregation-framework here] by the lead project manager at MongoDB<br/>.		At the time of writing the <code>aggregation()</code> method has no rounding functions, though it is still doable with <code>$mod</code> and <code>$multiply</code>, as shown [http://www.kamsky.org/stupid-tricks-with-mongodb/rounding-numbers-in-aggregation-framework here] by the lead project manager at MongoDB<br/>.
	</div>		</div>
	<div class="q nonum" data-lang="py3">~~MapReduce~~		==MapReduce==
			<div class="q nonum" data-lang="py3">
	<pre class=def>		<pre class=def>
	temp = db.world.map_reduce(		temp = db.world.map_reduce(
Line 36:		Line 37:
	</div>		</div>

	<div class="q nonum" data-lang="py3">~~Aggregate~~		==Aggregate==
			<div class="q nonum" data-lang="py3">
	<pre class=def>		<pre class=def>
	pp.pprint(list(		pp.pprint(list(

40166222 at 13:30, 28 July 2015

2015-07-28T13:30:01Z

← Older revision		Revision as of 13:30, 28 July 2015
Line 21:		Line 21:
	At the time of writing the <code>aggregation()</code> method has no rounding functions, though it is still doable with <code>$mod</code> and <code>$multiply</code>, as shown [http://www.kamsky.org/stupid-tricks-with-mongodb/rounding-numbers-in-aggregation-framework here] by the lead project manager at MongoDB<br/>.		At the time of writing the <code>aggregation()</code> method has no rounding functions, though it is still doable with <code>$mod</code> and <code>$multiply</code>, as shown [http://www.kamsky.org/stupid-tricks-with-mongodb/rounding-numbers-in-aggregation-framework here] by the lead project manager at MongoDB<br/>.
	</div>		</div>
	<div class=q data-lang="py3">MapReduce		<div class="q nonum" data-lang="py3">MapReduce
	<pre class=def>		<pre class=def>
	temp = db.world.map_reduce(		temp = db.world.map_reduce(
Line 36:		Line 36:
	</div>		</div>

	<div class=q data-lang="py3">Aggregate		<div class="q nonum" data-lang="py3">Aggregate
	<pre class=def>		<pre class=def>
	pp.pprint(list(		pp.pprint(list(

40166222 at 11:54, 28 July 2015

2015-07-28T11:54:50Z

← Older revision		Revision as of 11:54, 28 July 2015
Line 16:		Line 16:
	</pre>		</pre>
	{{TopTenTips}}		{{TopTenTips}}
	<div style="height:25em">		<div style="min-height:25em">
	Rounding is easy inside a <code>MapReduce</code> as it is possible to use the <code>Math</code> object provided by JavaScript.<br/>		Rounding is easy inside a <code>MapReduce</code> as it is possible to use the <code>Math</code> object provided by JavaScript.<br/>
	More information on <code>Math</code> can be found [https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Math here].<br/><br/>		More information on <code>Math</code> can be found [https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Math here].<br/><br/>

40166222: 40166222 moved page Rounding to Round without leaving a redirect

2015-07-27T12:52:30Z

40166222 moved page Rounding to Round without leaving a redirect

← Older revision	Revision as of 12:52, 27 July 2015
(No difference)

40166222 at 15:39, 26 July 2015

2015-07-26T15:39:39Z

← Older revision		Revision as of 15:39, 26 July 2015
Line 16:		Line 16:
	</pre>		</pre>
	{{TopTenTips}}		{{TopTenTips}}
			<div style="height:25em">
	Rounding is easy inside a <code>MapReduce</code> as it is possible to use the <code>Math</code> object provided by JavaScript.<br/>		Rounding is easy inside a <code>MapReduce</code> as it is possible to use the <code>Math</code> object provided by JavaScript.<br/>
	More information on <code>Math</code> can be found [https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Math here].<br/><br/>		More information on <code>Math</code> can be found [https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Math here].<br/><br/>
	At the time of writing the <code>aggregation()</code> method has no rounding functions, though it is still doable with <code>$mod</code> and <code>$multiply</code>, as shown [http://www.kamsky.org/stupid-tricks-with-mongodb/rounding-numbers-in-aggregation-framework here] by the lead project manager at MongoDB<br/>.		At the time of writing the <code>aggregation()</code> method has no rounding functions, though it is still doable with <code>$mod</code> and <code>$multiply</code>, as shown [http://www.kamsky.org/stupid-tricks-with-mongodb/rounding-numbers-in-aggregation-framework here] by the lead project manager at MongoDB<br/>.
			</div>
	~~<div class='extra_space' style='width:1em; height:20em;'>~~</div>
	<div class=q data-lang="py3">MapReduce		<div class=q data-lang="py3">MapReduce
	<pre class=def>		<pre class=def>