R vs Python: Image Classification with Keras

Even though the libraries for R from Python, or Python from R code execution existed since years and despite of a recent announcement of Ursa Labs foundation by Wes McKinney who is aiming to join forces with RStudio foundation, Hadley Wickham in particularly, (find more here) to improve data scientists workflow and unify libraries to be used not only in Python, but in any programming language used by data scientists, some data professionals are still very strict on the language to be used for ANN models limiting their dev. environment exclusively to Python.

As a continuation of my R vs. Python comparison, I decided to test performance of both languages in terms of time required to train a convolutional neural network based model for image recognition. As the starting point, I took the blog post by Dr. Shirin Glander on how easy it is to build a CNN model in R using Keras.

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Travelflex Cryptocurrency Mining on CUDA in Ubuntu 16.04


Following one of the main trends of 2017, I decided to join the new world of cryptocurrency and bought 1000 TRF coins during the first wave of Travelflex ICO. I choose exactly this currency of out hundreds existing ones for three reasons:

  1. Travel industry is very promising, and the ability of fast money transfer without fees would be an awesome asset for travelers.
  2. Travelflex claims a record high transaction rate of up to 1400 tps (transactions per second). This rate level makes the TRF algorithm to be one of the fastest among all cryptocurrencies existing today.
  3. As a consequence of the reason 2, easy shopping in almost any store accepting VISA/MasterCard and very simple way to withdraw cash of a local fiat currency (e.g. Euro, or USD) at an ATM through using Travelflex plastic cards (issuing expected in 2018, Q3). Printable checks will be also available even before the cards, delivery start was scheduled to 2018, Q2.

Next logical step after buying your first coins would be to mine them in order to gain more coins (BTW, in case you aren’t familiar with the cryptocurrency terminology you could start off by reading Travelflex FAQ). The Travelflex team published the instructions on how to start mining TRF. That is exactly what any cryptocurrency mining beginner as me would need to start with, so TRF team, thanks for your twitter post with the link to instructons.

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OSM Nominatim with R: getting Location’s Geo-coordinates by its Address

It is quite likely to get address info when scraping data from the web, but not geo-coordinates which may be required for further analysis like clustering. Thus geocoding is often needed to get location’s coordinates by its address.

There are several options, including one of the most popular, google geocoding API. This option can be easily implemented into R with the function geocode from the library ggmap. It has the limitation of 2500 request a day (when it’s used free of charge), see details here.

To increase the number of free of charge geocoding requests, OpenStreetMap (OSM) Nominatim API can be used. OSM allows up to 1 request per second (see the usage policy), that gives about 35 times more API calls compared to the google geocoding API.

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