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SEARCH KEYWORD -- accuracy



  Accurate floating point number calculation in JavaScript

In JavaScript, since floating point is defined with IEEE754,there will be some accuracy issues while doing floating point number arithmetic. Here is a function which can resolve the accuracy issue. var calc = function(num1,operator,num2,len){    var numFixs = function(num){        var arr = num.toFixed(len).toString().split('.');        return parseInt(arr.join(''));    }    switch(operator){...

   JavaScript, floating point,IEEE 754,accuracy     2012-12-27 11:07:49

  Data type in MySQL

For both small free database space and large e-commerce websites, reasonable database table structure design is essential. To achieve this, it requires us to have a full understanding of commonly used data types in database system. Below we share some knowledge about data types in MySQL.1. Numeric typesThe numeric types can be classified as : integer, float and decimal type.The so-called "decimal" refers DECIMAL and NUMERIC, they are of the same type. Strictly speaking it is not a numeric type, ...

   MySQL, Data type,VARCHAR     2013-01-01 10:56:06

  Microsoft is going to redesign Bing again

On 10 May,2012, Microsoft announces in San Francisco they will  redesign its search engine Bing, and it will cooperate with Facebook, Twitter etc to build a new search service.Bing now is the second largest search engine in the world, but compared to Google, Bing is always the second city of search. Bing these years has always been putting effort on improving its service and the accuracy of search results. Unfortunately, it still cannot gain market share from Google. Today, Microsoft is goi...

   Bing,Social network,Integration,Sidebar     2012-05-11 05:26:11

  Nokia : Nokia map is better than Apple map

Recently, the new release of Apple map is criticized by many users because of its search results accuracy. By this time, Nokia which has its map service Ovi Maps has a comparison of three maps in its Conversations blog. These three maps are the one on the Lumia 920, the Google Map on Samsung Galaxy S3, the map on Apple iPhone 5, It wants to show that Nokia is the best among them. Let's take a look:1. Offline modeOn Lumia 920 Map, the map of the entire country is downloaded, you can position, sea...

   Lumia 920,Galaxy s3,iPhone 5,Map     2012-09-22 00:09:24

  Why 0.1+0.2 != 0.3

In programming languages such as JavaScript, c/c++, Java and Matlab, you will find that you will get unexpected result when doing float point calculation. For example, when calculating 0.1 + 0.1, you will not get 0.3: > 0.1 + 0.2 == 0.3 false > 0.1 + 0.2 0.30000000000000004 Don't be surprised of this result, this is the end result of IEEE 754 standard, float point number cannot be accurately represented according to IEEE 754 because: No enough memory is allocated for representing the num...

   float point,comparison,JavaScript     2014-11-19 05:32:46

  Google releases new app to improve the accuracy of indoor positioning

Google Maps, Bing Maps, and some map providers have offered indoor map service such as in  the airport, major shopping malls and stadiums for some time. The problem is that these indoor maps can not precisely tell you which floor you are on a map, the GPS obviously can not work very well in this environment, WiFi and GPRS positioning is not very precise. Google announced the improvement program of Google Maps for accurate indoor positioning. The current owners of these places will cooperat...

   Google Map,Indoor service,Positioning     2012-04-08 09:46:53

  Measure the improvement of Google search algorithm

On the day of Google's 15th birthday, Google released its new "Hummingbird" search algorithm, this is the first time that Google changes its search algorithm since 2010 after the Caffeine algorithm. It will affect 90% of search results, according to Amit Singhal, Lead of Google Search. Some may be curious about how Google measures the improvement of a new search algorithm. There are many factors need to be considered, for example, accuracy, relevance, search depth etc. According to Amit Singhal...

   Google search,Algorithm, improvement     2013-09-29 23:25:53

  iPhone 5 first weekend sales over 5 million

Within 24 hours openning for pre-order, 2 million iPhone 5 have been ordered, Apple announces that  sales of iPhone 5 are over 5 million in 3 days on sale., in addition, iOS devices upgraded to iOS6 are around 100 million. Apple CEO Tim Cook says : Demand for iPhone 5 has been incredible and we are working hard to get an iPhone 5 into the hands of every customer who wants one as quickly as possible,While we have sold out of our initial supply, stores continue to receive iPhone 5 shipments ...

   iPhone5,,iOS6,sale,pre-order     2012-09-24 10:55:12

  How Speeding The "Most Important Algorithm Of Our Lifetime" Could Change This Modern World

Math breakthroughs don't often capture the headlines--but MIT researchers have just made one that could lead to all sorts of amazing technological breakthroughs that in just a few years will touch every hour of your life. Last week at the Association for Computing Machinery's Symposium on Discrete Algorithms (SODA) a new way of calculating Fast Fourier Transforms was presented by a group of MIT researchers. It's possible that under cert...

   FFT,Speed-up,Fast fourier transform     2012-03-20 07:47:04

  Why are ugly websites so successful?

“Techmeme has redesigned,” Gabe Rivera founder of the popular technology news site wrote in January 2012. “Drudge Report is now indisputably the web’s ugliest news site.” I use Techmeme all the time. I find it an excellent news website. It’s a collection of well-selected links to important issues in the technology industry. It doesn’t look pretty but it works fine for me. Asides from the quality of its stories it also has black text on white bac...

   Website design,Ugly,Success,Analysis     2012-02-13 05:27:56