# AnalyticBridge

A Data Science Central Community

# Alex Woods's Blog (7)

### Linear Algebra in Julia

Most people (including myself) are drawn to Julia by its lofty goals. Speed of C, statistical packages of R, and ease of Python?—it sounds two good to be true. However, I haven't seen anyone who has looked into it say the developers behind the language aren't on track to accomplish these goals.…

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Added by Alex Woods on August 23, 2015 at 4:30pm — No Comments

### Generating Text Using a Markov Model

A Markov Chain is a random process, where we assume the previous state(s) hold sufficient predictive power in predicting the next state. Unlike flipping a coin, these events are dependent. It’s easier to understand through an example.…

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Added by Alex Woods on August 4, 2015 at 8:00pm — No Comments

### Introduction to Monte Carlo Methods

I’m going to keep this tutorial light on math, because the goal is just to give a general understanding.

The idea of Monte Carlo methods is this—generate some random samples for some random variable of interest, then use these samples to compute values you’re interested in.

I know, super broad. The truth is Monte Carlo has a ton of different applications. It’s…

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Added by Alex Woods on July 25, 2015 at 6:00pm — 5 Comments

### Guide To Linear Regression

Linear regression is one of the first things you should try if you’re modeling a linear relationship (actually, non-linear relationships too!). It’s fairly simple, and probably the first thing to learn when tackling machine learning.

At first, linear regression shows up just as a simple equation for a line. In machine learning, the weights are usually represented by a vector θ (in statistics they’re often represented…

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Added by Alex Woods on July 19, 2015 at 8:31am — 1 Comment

### Linear Algebra for Data Scientists

It’s important to know what goes on inside a machine learning algorithm. But it’s hard. There is some pretty intense math happening, much of which is linear algebra. When I took Andrew Ng’s course on machine learning, I found the hardest part was the linear…

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Added by Alex Woods on July 10, 2015 at 10:30pm — No Comments

### Random Forest in Python

Random Forest is a machine learning algorithm used for classification, regression, and feature selection. It's an ensemble technique, meaning it combines the output of one weaker technique in order to get a stronger result.

The weaker technique in this case is a decision tree. Decision trees work by splitting the and re-splitting the data by…

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Added by Alex Woods on July 4, 2015 at 8:30am — No Comments

### Basic Data Exploration in R

When you're cleaning up data, you usually end up using a 5-8 functions a ton of times, and then a few more once or twice. Here are those 5-8 functions I find myself using again and again.

Here is a quick overview:

names() - returns the column names of a dateset…

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Added by Alex Woods on July 4, 2015 at 8:00am — No Comments

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