d3.js - Reducing Large Datasets with MongoDB and D3 -


i'm working on d3 visualization , luckily have made progress. however, i've run issue... , honest, i'm not sure if mongodb issue, or d3 issue. see, i'm trying make series of graphs set of sensor points (my json object contains timestamps, light, temperature, humidity, , motion detection levels or each datapoint). however, sensors uploading data mongodb database every 8 seconds. so, if query mongodb database 1 days worth of data... 10,800 datapoints. worse, if ask 1 month of data, i'd swamped 324,000 datapoints. issue d3 visualization slows crawl when dealing more 1000 points (i'm visualizing data on 4 different graphs each use single brush select domain on graph. there way limit amount of data i'm trying visualize? better done using mongodb (so filter data i'm querying , getting every nth data point based on how big of time value i'm trying query). or there better way? should try filter data using d3 once i've retrieved entire dataset? best way go reducing amount of points need deal with? in advance.

mongodb great @ filtering. if need subset of data, specify in find query -- limit subset of time, or if you're clever data first minute of every hour or similar.

or can literally reduce amount of data coming out of mongodb using aggregation framework. used partial sums or averages or similar.


Comments

Post a Comment

Popular posts from this blog

ios - iPhone/iPad different view orientations in different views , and apple approval process -

i force app's home screen portrait , other views landscape. apple rejects app if this? if not , how force first screen launch in portrait mode? , force other screens launch in landscape. this not duplicate question search every possible answer in website. i force app's home screen portrait , other views landscape. apple rejects app if this? no apple not reject app this. have lot of apps doesn't support orientation. forcing on 1 screen won't cause app reject. if not , how force first screen launch in portrait mode? , force other screens launch in landscape. can on write : -(nsuinteger)supportedinterfaceorientations; function.
Read more

java Extracting Zip file -

i'm looking way extract zip file. far have tried java.util.zip , org.apache.commons.compress, both gave corrupted output. basically, input zip file contain 1 single .doc file. java.util.zip: output corrupted. org.apache.commons.compress: output blank file, 2 mb size. so far commercial software winrar work perfectly. there java library make use of this? this method using java.util library: public void extractzipnative(file filezip) { zipinputstream zis; stringbuilder sb; try { zis = new zipinputstream(new fileinputstream(filezip)); zipentry ze = zis.getnextentry(); byte[] buffer = new byte[(int) ze.getsize()]; fileoutputstream fos = new fileoutputstream(this.tempfolderpath+ze.getname()); int len; while ((len=zis.read(buffer))>0) { fos.write(buffer); } fos.flush(); fos.close(); } catch (filenotfoundexception e) { // todo auto-generated catch block ...
Read more

C# WinForm - loading screen -

i ask how make loading screen (just picture or something) appears while program being loaded, , disappears when program has finished loading. in fancier versions, have seen process bar (%) displayed. how can have that, , how calculate % show on it? i know there form_load() event, not see form_loaded() event, or % property / attribute anywhere. all need create 1 form splash screen , show before main start showing landing page , close splash once landing page loaded. class splashform { //delegate cross thread call close private delegate void closedelegate(); //the type of form displayed splash screen. private static splashform splashform; static public void showsplashscreen() { // make sure launched once. if (splashform != null) return; thread thread = new thread(new threadstart(splashform.showform)); thread.isbackground = true; thread.setapartmentstate(apartmentstate.sta); thread....
Read more