This Gist is mostly for my future self, as a reminder of how to find distances between each row in two different matrices. To create a distance matrix from a single matrix, the function dist(), from the stats package is sufficient.

There are times, however, when I want to see how close each row of a matrix is to another set of observations, and thus I want to find distances between two matrices. For example, consider a set of voter ideal points in several dimensions, from which I want to find the distance to a set of candidate ideal points in those same dimensions.

Creating a distance matrix can get very memory-intensive, so it is useful to focus only on finding the distances one needs, rather than calculating an entire n Ć n matrix and ignoring most of it. For this purpose, I use the dist() function from the proxy package, as shown below.

I also include an example of the use of multidimensional scaling on a distance matrix, to show how useful this simple operation can be.

*Related*

To

**leave a comment** for the author, please follow the link and comment on their blog:

** is.R()**.

R-bloggers.com offers

**daily e-mail updates** about

R news and

tutorials on topics such as:

Data science,

Big Data, R jobs, visualization (

ggplot2,

Boxplots,

maps,

animation), programming (

RStudio,

Sweave,

LaTeX,

SQL,

Eclipse,

git,

hadoop,

Web Scraping) statistics (

regression,

PCA,

time series,

trading) and more...

If you got this far, why not

__subscribe for updates__ from the site? Choose your flavor:

e-mail,

twitter,

RSS, or

facebook...

**Tags:** MASS, matrixManipulation, proxy, rstats, Zelig