algorithm


Is Python or Perl faster than R?

@machinelearnbot

Though a lot of statistical / machine learning algorithms are now being implemented in Python - see Python and R articles - and it seems that Python is more appropriate for production code and big data flowing in real time, while R is often used for EDA - exporatory data analysis - in manual mode. My question is, if you make a true apple-to-apple comparison, what kind of computations does Python perform much faster than R, (or the other way around) depending on data size / memory size? Here I have in mind algorithms such as classifying millions of keywords, something requiring trillions of operations and not easy to do with Hadoop, requiring very efficient algorithms designed for sparse data (sometimes called sparse computing). For instance, the following article topic (see data science book pp 118-122) shows a Perl script running 10 times faster than the R equivalent, to produce R videos, but it's not because of a language or compiler issue, it's because the Perl version pre-computes all video frames very fast and load them in memory, then the video is displayed (using R ironically), while the R version produces (and displays) one frame at a time and does the whole job in R. What about accelerating tools, such as the CUDA accelerator for R?


What Execs Should Know About Deep Learning - InformationWeek

#artificialintelligence

Simply put, machine learning uses algorithms to find patterns in data fed to it by humans. Traditional machine learning requires humans to provide context for data -- something called feature engineering -- so a machine can make better predictions. Deep learning is great for video, speech or images. Traditional machine learning models can't make heads-or-tails of complex images, for example.


Facebook Uses Artificial Intelligence to Fight Terrorism

#artificialintelligence

"We want to find terrorist content immediately, before people in our community have seen it," read the message posted Thursday. AI, Facebook says, is also useful for identifying and removing "terrorist clusters." So when we identify pages, groups, posts or profiles as supporting terrorism, we also use algorithms to "fan out" to try to identify related material that may also support terrorism." Facebook said AI has helped identify and remove fake accounts made by "repeat offenders."


A Semi-Supervised Classification Algorithm using Markov Chain and Random Walk in R

@machinelearnbot

From each of the unlabeled points (Markov states) a random walk with Markov transition matrix (computed from the row-stochastic kernelized distance matrix) will be started that will end in one labeled state, which will be an absorbing state in the Markov Chain. As can be seen, with increasing iterations, the probability that the state ends in that particular red absorbing state with state index 323 increases, the length of a bar in the second barplot represents the probability after an iteration and the color represents two absorbing and the other unlabeled states, where the w vector shown contains 1000 states, since the number of datapoints 1000. Each time a new unlabeled (black) point is selected, a random walk is started with the underlying Markov transition matrix and the power-iteration is continued until it terminates to one of the absorbing states with high probability. Since only two absorbing states are there, finally the point will be labeled with the label (red or blue) of the absorbing state where the random walk is likely to terminate with higher probability.


How Does the Random Forest Algorithm Work in Machine Learning

#artificialintelligence

In decision tree algorithm calculating these nodes and forming the rules will happen using the information gain and gini index calculations. In random forest algorithm, Instead of using information gain or gini index for calculating the root node, the process of finding the root node and splitting the feature nodes will happen randomly. In the above Mady trip planning, two main interesting algorithms decision tree algorithm and random forest algorithm used. First, let's begin with random forest creation pseudocode The beginning of random forest algorithm starts with randomly selecting "k" features out of total "m" features.


7 must-have traits for a successful data team

#artificialintelligence

So I want to lay out some of the skills that business leaders should be looking for when they hire data professionals today--whether they be data analysts, data engineers, data product managers, or data scientists. If an analyst's idea of presenting findings to business stakeholders is saying "We found a strong negative correlation--R 2 0.53. Too many data science training programs focus intensely on teaching the algorithms that data scientists use, using pristine datasets that are never found in the real world. They ignore the fact that most of a data scientist's time is actually spent finding, cleaning, and reshaping raw data to make it ready for modeling.


Deep Learning personalization of Internet is next big leap - AI Trends

#artificialintelligence

On a basic conceptual level, deep learning approaches share a very basic trait. Google Translate's science-fiction-like „Word Lens" function is powered by a deep learning algorithm and Deep Mind's recent Go victory can also be attributed to DL – although the triumphant algorithm AlphaGo isn't a pure neural net, but a hybrid, melding deep reinforcement learning with one of the foundational techniques of classical AI -- tree-search. Deep learning is an ample approach to tackling computational problems that are too complicated to solve for simple algorithms, such as image classification or natural language processing. It is quite possible that a large portion of the industries that currently leverage machine learning hold further unexploited potential for deep learning and DL-based approaches can trump current best practices in many of them.


Python: Implementing a k-means algorithm with sklearn

@machinelearnbot

The purpose of k-means clustering is to be able to partition observations in a dataset into a specific number of clusters in order to aid in analysis of the data. Specifically, the k-means scatter plot will illustrate the clustering of specific stock returns according to their dividend yield. Specifically, we are devising a range from 1 to 20 (which represents our number of clusters), and our score variable denotes the percentage of variance explained by the number of clusters. Therefore, we set n_clusters equal to 3, and upon generating the k-means output use the data originally transformed using pca in order to plot the clusters: From the above, we see that the clustering algorithm demonstrates an overall positive correlation between stock returns and dividend yields, implying that stocks paying higher dividend yields can be expected to have higher overall returns.


Exoskeletons Don't Come One-Size-Fits-All ... Yet

WIRED

So far, automatically tuning an exoskeleton's force, and the timing of that oomf, is faster and better than hand-tuning. Thursday, in a paper published in Science, Poggensee and her fellow researchers outline an algorithm that calibrates an exoskeleton to best assist its user. Meanwhile, the tuning algorithm cycled through four sets of eight different patterns of assistive torque, varied in timing and amount of force. We Take Hyundai's Iron Man-Inspired Exoskeletons for a Spin After about an hour of this strolling, the algorithm pinned down the optimal timing and torque to minimize the energy cost of each walker's gait.


Machine learning in cybersecurity is coming to IAM systems

#artificialintelligence

Several experts at the 2017 Cloud Identity Summit this week discussed machine learning in cybersecurity applications for identity management systems, as well the risks and rewards of such applications. And to give an idea of the volume of activity that identity management systems are dealing with today, Simons said his company sees 115.5 million blocked log in attempts and 15.8 million takeover attempts for Microsoft accounts each day. Maass said if the baseline for good behavior is set incorrectly, then the identity management systems will learn incorrectly and make mistakes. Dholakia cited another potential problem for machine learning-powered IAM: Continuous and possibly endless accumulation of data for identity management systems will make machine learning in cybersecurity applications increasingly complex and harder for actual human identity professionals to manage.