codigo

Polynomial Regression

Polynomial Regression is a form of linear regression model but fits a non-linear relationship between the value X and Y. Basically we have to add new features to the final equation. But what features? It's simple we can add the X1 feature as new feature: X1^2 or X1^3. If we have some input features (X1,X2,X3) also we can add new features as X1*X2 or X1^2*X3^2. So, the polynomial regression model is:

As you can see in the following figure you can get a linear regression (red line) or you can get a non-linear regression (blue and  yellow) if you add more features to your equation. The type of curve of non-linear regression model depends of the grade of your polynomial. If the grade of the polynomial is near 1 the model fits to traditional linear regression model. Instead, if the grade of the polynomial is high the model fits to training points.

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By rocapal, ago
codigo

Multi-variable linear regression

I continue working with machine learning algorithms. In a previous post I talked about linear regression with one variable and I described different algorithms to predict hypothesis.

In this case, I'm playing with linear regression but, with some features. Linear regression only have one input feature and one output feature. For example, you can predict the price of a house give the house's size. But imagine that you want predict the price of a house using size and rooms features. When you have more than one input feature is called 'multi-variable linear regression'.

In the following figure we can see the two input features (size and rooms), the training data (red dots), and the predictions (blue dots). In this case, we can represent the information with a 3D model. If your model have more than three features you must research the way to represent all the data.

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By rocapal, ago
android

Arduino & Android & ADK

The last Google I/O a new feature based in Android and Arduino was released. The ADK allows the communication between Android and Arduino using a USB connection. Google have developed a library called “USB Accessory” in Android and Arduino. So, this library help us to send and receive data through USB interface. Using Read more…

By rocapal, ago
android

AR interface in Android using phoneGap

Since 6 months ago we have evaluated the possibility to implement a new AR interface (based in our project ARviewer) using phoneGap. phoneGap is a mobile framework based in HTML5/JS that allow execute the same source code HTML5 in differents mobile platforms (iphone, android, blackberry). It seem a good way Read more…

By rocapal, ago
android

Android: TimerTask y GUI

Voy a retomar después de meses el blog, a ver si consigo documentar cada problema que me encuentro mientras programo con Android. Hoy me he topado con un problema típico cuando programas con GUI gráfica, y es que muchas veces necesitamos actualizar o interactuar con la interfaz gráfica desde un Read more…

By rocapal, ago