# Uppyn's Blog

The world through Dutch eyes in Sydney

## Monthly Archives: April 2010

## Learning R – simple linear regression

Basic linear regression is very important in engineering and science. In linear regression one tries to fit a line to whatever data you are sitting on top of. The objective is off course to investigate if that line would reveal a meaningful relationship between the variables of your data. The linear regression can also be used to test a hypothesis that tells you if the new-found relationship is statistically significant.

Depending on the format of your data, it is pretty easy to do a simple linear regression in R. To do that, we first need to get some data. In this case I use a simple data file that contains measurements of the boiling point of water as a function of height. The data is available on the internet but I downloaded to my hard disk. Here is the content of the file:

## Learning R – a second step

In the last post I have done something very simple: I called the built-in data set ‘sunspots’ and drew a basic plot. With very basic means I can do some more to this plot. E.g. I can add a title and titles for the axes:

plot(sunspots,xlab=”years”,ylab = “sunspot count”,main = “Sunspot numbers”)