Monthly Archives: March 2011

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 filter rows based on an element

Posted on March 21, 2011 by joelgranados

I need to separate a matrix based on the existence of an element in a row.  I will end up with two matrices: the first will not contain the element on any of its rows and the second will contain … Continue reading →

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Remove defined variables from R environment

Posted on March 18, 2011 by joelgranados

When I am debugging a piece of code I usually do it inside the R-terminal.  It’s nice to do things this way because you can poke at things when something goes wrong.  The only disadvantage is that you mush “refresh” … Continue reading →

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opencv add padding

Posted on March 5, 2011 by joelgranados

I was surprised that this function was so difficult to find.  I googled with the title of this post and did not find any real solution to what I was looking for.  I just want to add some pixels of … 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 →

Posted in commands, R | 3 Comments