Category Archives: commands

These are useful linux commands that I have found while doing stuff. Putting them here so I don’t forget.

R: Efficient data loading

Posted on March 26, 2011 by joelgranados

I’m working with the HOG_01 directory from this dataset.  They have organized so that each data point is a 1568 line text file.  The data sets are also separated in 43 types.  Unzip the data and you will see what … Continue reading →

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R : Finding the ordering index vector

Posted on March 1, 2011 by joelgranados

The ordering index vector is a vector that contains indices of another vector.  It’s basically the other vector, but ordered (decreasing or increasing).  Instead of having the values it has the indices :)  I spent close to an hour to … Continue reading →

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Curious rounding in R

Posted on February 25, 2011 by joelgranados

Sometimes R has a misleading way of displaying values.  Check out this series of commands: > 1111+.5 [1] 1111.5 > 11111+.5 [1] 11111.5 > 111111+.5 [1] 111111.5 > 1111111+.5 [1] 1111112 > 11111111+.5 [1] 11111112 At first I thought that … Continue reading →

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Adjusting point size in R plots.

Posted on February 9, 2011 by joelgranados

The trick here is to manage the pch and cex arguments in the plot function.  You can look at more information on these arguments in ?plot, ?par and ?points in the R environment (search for cex and pch).  In general … Continue reading →

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How to output an eps figure in R

Posted on February 8, 2011 by joelgranados

If you are executing a plot command in a R script it should default to generating a pdf document with your plot.  This is really cool because you don’t really have to think about how to show what you have … Continue reading →

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Sending mail from the console is cool! ssmtp with gmail.

Posted on December 6, 2010 by joelgranados

Quick Cheat-sheet on configuring ssmtp on my machine.  This is really cool for me because it enables me to send git patches from console.  I confess, I like the console. yum install ssmtp -y cat << EOF > root=postmaster mailhub=smtp.gmail.com:587 … Continue reading →

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The convert command. Nice!

Posted on September 17, 2010 by joelgranados

I’ve actually used this command before but today I was pleasantly surprised.  I had used it in the past to change from one image format to another.  It’s actually very straight forward and it helps a bunch when you just … Continue reading →

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gmail: filter attachment names and auto responses

Posted on September 8, 2010 by joelgranados

Searching for a way to better the current way of receiving assignments (We should probably be using something like egroupware for universities, one can dream) I stumbled upon some nifty tricks to make life that much easier. The issue came … Continue reading →

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Convert 3gp to AVI

Posted on August 5, 2010 by joelgranados

Took some video with my phone (HTC hero) and it ended up being encoded in 3gp.  When I went to use it with my opencv code: BUM!!!! it exploded.  So I chose to change from 3gp to AVI, which I … Continue reading →

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