IT advisor, R and RPi fan.
I used to create a shiny-app to conduct image classification using Tensorflow on DigitalOcean, however it didn’t work on my own PC station. The main problem is: RStudio-server and Shiny-server can’t find the shared object: libcudart.so.8.0 which located under /usr/local/cuda/lib64...
With more than 10 years’ experience of using Linux, I have never been bothered by copy/delete a folder using: sudo cp -R source dest and sudo rm -R folder, untill I decided to play with BigData.
I have a modern...
I have been always using multiprocessing in my web crawlers to accelerate the processing. Today, I want test how much fast the storageEngine WiredTiger vs MMAPV1 in MongoDB. The result is what expected for inserting document using single thread: 20%...
I need more disk space of my computer, so I bought a 3TB hard disk. I want the new disk to be one partion, so I can easily distinguish it from others.
After connecting the hard disk to computer and...
If you want to play computer vision, opencv is the most popular tool. However, installing opencv is not like install a normal software, it is more complete, and you may need hours to finish the installation. Adrian Rosebrock...
R is a single thread program, which can use only one CPU core, for multiple concurrent requests, it will conduct one by one until the last one was finished. Modern computers generally have several cores CPU, a simple way to...
I used to scrape web pages on my SDD, because I think saving files on SDD will be fater than on HDD, like many posts said. Recently, I have to save files on my HDD, because the SDD is full,...
Multiprocessing is used to accelerate the scraping of web pages, while using proxies can hide your IP address, and avoid the server ban your crawlers. This post take an example to show you how to write such a crawler in...
Though, Ryan Mitchell said web scraping is legal in his book: Web Scraping with Python Collecting Data from the Modern Web, we still can read some reports that companies lose the court cases due to they scraped huge data from...
The official instruction for install MongoDB on Ubuntu system can be found here.
In the Overview part, it said:
While Ubuntu includes its own MongoDB packages, the official MongoDB Community Edition packages are generally more up-to-date.
I...
In previous post, I described how to download all topics pages of Shiny Google Group. The download topics are in html format, in this post, I will describe how to extact useful information, and import the result into R.
There...
There are a lof of places to ask for help, e.g. StackOverflow, Google Groups, GitHub, etc. If you want to know who are the experts on a field or who are active on a field you can download all the...
Data management is the first skill of a data scientist, in my opinion. The management task generally includes import data from one form into another one (generally a database). But sometimes, we need to collect the data ourselves, for example...
I have the idea to build a website for many years. There are many excuses why I didn’t, one important is there are many free alternatives, like github project blog. But now, I want to build one for myself after...
I have written two blogs recording my experience of installing shiny-server on Ubuntu 12.04 & 14.04, now it’s the turn of Ubuntu 16.04. There is a little difference, just for memory.
I suggest you do not install TensorFlow from source, because it could be a nightmare! I spent more than 10 hours to figure out all the bugs. If you have Ubuntu 16.04 installed on your computer, I suggest you to...
I decided to learn some knowledge about Machine Learning or Artificial Intelligence though I have no idea what I can use it for. I believe a Data Scientist can’t keep his competence in next 10 years if he was not...
Unarguably, PowerPoint is still the most widely used presentation tool. And I do admit that PowerPoint is good at many tasks, such like drawing any kind of shapes. But, we all know “point-and-click” is not efficient when there are many...
Most of the tutorials available are for EAP WiFi, which require just a password. PEAP WiFi network used generally for company, and each user has an ID and a password. To access this kind of WiFi network is also very...
I bought a VIVO X7Plus recently (2016-07-30) when I was in China. However, due to in China, I can’t use Gmail, so I didn’t setup my Gmail. When I back to Norway, and try to use Gmail, which I have...
This post shows how to configure an autocommit environment for GitLab (an internal version of Github).
Suppose you have a project under folder: myproject, you want to save each version of your project and save it on GitLab for security...
Shopping list:
TensorFlow’s official website presented different ways to install TensorFlow. I tried the pip install, and after several times fail, finially I can pass the test your installation. However, when I try to run the tutorial of Image Recognition,...
Several years ago, I created a web page to show the exam scores of schools in Norway on Google Map. The original intention of creating that web page is to help us avoid the area where the schools’ score are...
I bought a domain name from Godaddy long time ago. I thought to configure a domain name will take some time, that’s the excuse why I didn’t use it until now (shame on me). Now I have to link my...
I have to write this blog because it always needs half day to get everything work. Note: always download 64-bit version softwares, if you use 64-bit computer.
Download Git and install it. Run Git Bash, and...
You may have interest about who visited your web site, and it’s better if you can see them on map, like this one. In this blog, I will show you how to create a such kind of shiny-app to...
Several people asked me if I ever installed Shiny Server on Raspberry Pi (RPi) because I introduce myself as a “R and Raspberry Pi fan” on my blogs. Though I don’t think RPi is suitable to hold a Shiny...
I have googled a lot, finally I found the guideline of Mike Haldas is the easiest way to stream Raspberry Pi Video. Here I simplified the steps as:
1. Enable RPi camera if it was not.
By default, we need to setup the minimum and maximum throttle of a brushless ESC....
I have set up a Shiny Server on Ubuntu 12.04 in 2013. Shiny package has been under active development, and current version has reached 0.11 while the one on my server is still 0.8. I should keep update with...
Raspberry Pi is a credit-card sized (not the thickness) Linux computer, besides its small size, it has pins (GPIO, I2C, etc) which allow you to connect other electrical devices, like motors, servo, sensors, LED, etc. I felt in love...
Highcharts is the best JavaScript chart library, I feel. By default, there is an export button which can let you save the interactive figure to PNG, JPEG, PDF and SVG format, and one important point is, you can use it...
It’s a common requirement that your Shiny application should be bilingual. I have tried several methods and finally I got one which is not so difficult to maintain.
My idea is:
When plot with R (or some other software), it doesn’t bother you a lot for choosing colors if you have only several data series. For example, if I want to create a figure for 5 data series, I can easily...
The Shiny-app on open-source edition Shiny-server has only one concurrent, which means it can run only for one user at a time point. But it can host multiple Shiny-apps, which can run synchronously. So, if we create severl Shiny-apps with...
I used to scrape static web pages with the R package RCurl. It’s a great package! When it comes to dynamic web pages, RCurl comes to be difficult to set up (actually, I never get it works). Then I met...
RStudio supplies several servers for hosting user’s apps, e.g. http://www.shinyapps.io/, http://spark.rstudio.com, http://glimmer.rstudio.com. Thanks a lot to RStudio who has contributed many excellent R libraries! I want to set my shiny-server on a virtual private server (VPS), because I...
If you have deployed your Shiny-app on internet, you may curious about: how many users are using my app? Is the server powerful enough for hosting the app? You can get answers through the Server monitoring feature if you...
There are a lot of JavaScript libraries for generating elegant and interactive charts, such as d3.js, RGraph, Google Charts, etc. However, most of them have no feature that can let users save their charts as images, except Highcharts! The...
Shiny-server integrates the statistic power of R with web, convenients the statistical analysis through web. Users can do complecate statistical anlysis through their web browsers. However, most of statistical analysis of R are CPU bound computation, that means CPU utilization...
In a previous blog, I post a simple authentication method for Shiny-app, and received several comments mainly concerning that I should encrypt user password. I agree, user’s password can be intercepted when it was transferring. To secure users’ personal...
A month ago, I attended a friend’s wedding as a photographer (I am not good at shooting, just have a not so bad camera). I took more than 1000 pictures in high quality format. Later, I relized to share them...
When we created a Shiny-app, deployed it on a server and open it to public, we must have interesting of who visited our app, and if possible, where they from and what they have done. To achieve this, we need...
A Calculation in process busy indicator for shiny application is useful especially for the application that take long time to calculate result. I used to developed an application do model fitting which need more than 10 seconds! Users may lose...
The commercial version of Shiny-server has an authentication feature for shiny application. Before the release of the commercial (and still for open source version) version Shiny-server, it’s not easy to add authentication feature to shiny application. I want to...
Frequently encountered, we need to schedule tasks: run task automatically! To schedule your R task, edit /etc/crontab like this:
sudo nano /etc/crontab At the end of the opened file, add such...
I have shown how to set character encoding through configuring system locale for R in previous post. But to find the correct encoding could be an not easy task if you don’t know some basic knowledge of encoding. I would...
R is so powerful and elegant, that attacts more and more people switch to it. Those users come from different places, speack different languages and possiblely use other statistical softwares. So they may encounter one anoying problem: garbled text or...
Just found this interesting package fortunes though it have been built for 9 years! I wrote a simple application and deployed it on Rstudio server, So you can read those wisdom where you have internet connection.
...There is a function called fileInput comes with Shiny-server, which can upload data to server. In this post, I would like to share my experience of uploading different kind of data (.txt, .csv, .xls, .xlsx, etc.) to Shiny-server.
The...
In previous post, I listed the issues of how to configure Shiny-server under Ubuntu which installed as parellel operation system with Windows. There are two shortcomings for that: I need to restart the computer to switch between the two...
This year, I fell in love with fly fishing. Lucky for me, there are a lot of nice places for fishing in Oslo forest. There is website called OFA listed what kind of fishes and their population density in...
Shiny is a R package allows you to create interactive web-based application which is getting more and more popular in R communities. It makes creating web application super simple if you are familiar with R. Though it requires...
I am a somewhat minimalist R user. I feel uncomfortable if something is not in a good order, such as the names of variables and documents, the structures of my codes and projects. I prefer my data stored in .txt...
For some reason, you want to know the shooting time of your photos. Generally, shooting time can be found as Date modified, if you didn’t made a lot of change to your photos. But, we often make change to our...