Difference between revisions of "Software tutorial/Extending R with packages"

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(Created page with "{{Navigation|Book=Software tutorial|previous=Dealing with distributions|current=Tutorial index|next=Programming in R: loops and flow control}} __NOTOC__ <rst> <rst-options: 't...")
 
 
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Even if you don't want to install extra packages, you should keep the built-in packages up to date.  You require an internet connection for this step.
Even if you don't want to install extra packages, you should keep the built-in packages up to date.  You require an internet connection for this step.


At the R command prompt, write:
.. rubric:: The manual approach is to write, at the R command prompt:


.. code-block:: s
.. code-block:: s
Line 21: Line 21:
update.packages()
update.packages()


.. rubric:: Mac users
.. rubric:: Or you can follow these steps in RStudio:


* Click on ``Packages & Data`` on the top menu
* Click on ``Tools`` on the top menu
* Choose ``Package Installer``
* Then choose ``Check for Package Updates...``
* Click ``Get list``
* If this is your first time updating, then you will have to select the closest update mirror (web site).   
* If this is your first time updating, then you will have to select the closest update mirror (web site).   
* Typically you would choose the mirror that is geographically closest to you: for example ``Canada (ON)``.  You can have R remember your choice for the future.
* Typically you would choose the mirror that is geographically closest to you: for example ``Canada (ON)``.  You can have R remember your choice for the future.
* Click on the ``Update All`` button to have R check that your built-in packages are up to date at the latest version.
* Click on the ``Install`` button to have R update all your packages to their latest version.  
 
.. rubric:: Windows users
 
* Click on ``Packages`` on the top menu
* Choose ``Update packages``
* If this is your first time updating, then you will have to select the closest update mirror (web site). 
* Typically you would choose the mirror that is geographically closest to you: for example ``Canada (ON)``.  You can have R remember your choice for the future.
* Click ``OK`` once it shows you the list of packages that will be updated.


R will fetch and install any updates it requires.
R will fetch and install any updates it requires.
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#. Googling: for example, the other day I needed to figure out how to plot time-series data nicely.  I came across a page that recommended the ``xts`` package.
#. Googling: for example, the other day I needed to figure out how to plot time-series data nicely.  I came across a page that recommended the ``xts`` package.


.. rubric:: Mac users
* Click on ``Tools`` on the top menu
 
* Choose ``Install Packages...``
* Click on ``Packages & Data`` on the top menu
* Type in the name of the package you found in the prior step.
* Choose ``Package Installer``
* Click ``Get list``
* Select the packages from the list (you can select more than one by holding down the ``Command`` key on a Mac).
* Make sure you select the check box ``Install dependencies``
* Make sure you select the check box ``Install dependencies``
* Then click "Install Selected"
* Then click "Install"
 
.. rubric:: Windows users
 
* Click on ``Packages`` on the top menu
* Choose ``Install packages``
* Select the package(s) you wish to install
* Click ``OK``


Once the library is installed, you first need to load it.  For example, to generate a nicer qq-plot using the ``car`` package:
Once the library is installed, you first need to load it.  For example, to generate a nicer qq-plot using the ``car`` package:
Line 74: Line 55:
will generate:
will generate:
</rst>
</rst>
[[Image:plot-qq-plot.jpg|500px|center]]
[[Image:Plot-qq-plot.jpg|500px|center]]
<rst>
<rst>
<rst-options: 'toc' = False/>
<rst-options: 'toc' = False/>
Line 83: Line 64:


help(package="car")
help(package="car")
</rst>
{{Navigation|Book=Software tutorial|previous=Dealing with distributions|current=Tutorial index|next=Programming in R: loops and flow control}}

Latest revision as of 09:48, 13 January 2016

← Dealing with distributions (previous step) Tutorial index Next step: Programming in R: loops and flow control →

<rst> <rst-options: 'toc' = False/> <rst-options: 'reset-figures' = False/> The basic R installation is pretty comprehensive. One of the advantages of R though is that it is constantly being updated with new packages. A package is collection of functions and other information that expand R's capabilities.

For example, the built-in ``qqnorm(...)`` can be used to test if a sequence of values came from a normal distribution. However, there is, in my opinion, a better qq-plot function in the ``car`` library, called ``qqPlot(...)``, however the ``car`` library does *not* come pre-installed with R.

This section shows how to install extra packages and to keep your R installation up to date.

Keeping R up to date


Even if you don't want to install extra packages, you should keep the built-in packages up to date. You require an internet connection for this step.

.. rubric:: The manual approach is to write, at the R command prompt:

.. code-block:: s

update.packages()

.. rubric:: Or you can follow these steps in RStudio:

  • Click on ``Tools`` on the top menu
  • Then choose ``Check for Package Updates...``
  • If this is your first time updating, then you will have to select the closest update mirror (web site).
  • Typically you would choose the mirror that is geographically closest to you: for example ``Canada (ON)``. You can have R remember your choice for the future.
  • Click on the ``Install`` button to have R update all your packages to their latest version.

R will fetch and install any updates it requires.

Installing a new package


Installing a new package is easy; finding the package to install that does what you want is a little tougher: there are over 2000 packages available. Here are 2 ways I typically discover packages.

  1. . By browsing the hierarchy of packages at http://cran.r-project.org/web/views/
  2. . Googling: for example, the other day I needed to figure out how to plot time-series data nicely. I came across a page that recommended the ``xts`` package.
  • Click on ``Tools`` on the top menu
  • Choose ``Install Packages...``
  • Type in the name of the package you found in the prior step.
  • Make sure you select the check box ``Install dependencies``
  • Then click "Install"

Once the library is installed, you first need to load it. For example, to generate a nicer qq-plot using the ``car`` package:

.. code-block:: s

data <- rnorm(100) # create 100 normally distributed values library(car) qqPlot(data)

will generate: </rst>

Plot-qq-plot.jpg

<rst> <rst-options: 'toc' = False/> <rst-options: 'reset-figures' = False/> To see a list of all functions that are provided by a package:

.. code-block:: s

help(package="car") </rst>

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