2365 search results for "map"

Basic R: rows that contain the maximum value of a variable

February 12, 2013
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Basic R: rows that contain the maximum value of a variable

File under “I keep forgetting how to do this basic, frequently-required task, so I’m writing it down here.” Let’s create a data frame which contains five variables, vars, named A – E, each of which appears twice, along with some measurements: Now, let’s say we want only the rows that contain the maximum values of

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What Analytic Software are People Discussing?

February 12, 2013
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What Analytic Software are People Discussing?

by Robert A. Muenchen How can we measure the popularity or market share of analytic software? One way is to see what people are discussing. I’m in the process of updating my annual article, The Popularity of Data Analysis Software. Below … Continue reading →

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The Problem with Testing for Heteroskedasticity in Probit Models

February 12, 2013
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The Problem with Testing for Heteroskedasticity in Probit Models

A friend recently asked whether I trusted the inferences from heteroskedastic probit models. I said no, because the heteroskedastic probit does not allow a researcher to distinguish between non-constant variance and a mis-specified mean function. In particular, my friend had a hypothesis that the variance of the latent outcome (commonly called "y-star") should increase with an

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More visualisation of 2012 NFL Quarterback performance with R

February 12, 2013
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More visualisation of 2012 NFL Quarterback performance with R

In last week’s post I used R heatmaps to visualise the performance of NFL Quarterbacks in 2012. This was done in a 2 step process, Clustering QB performance based on the 12 performance metrics using hierarchical clustering Plotting the performance clusters using R’s pheatmap library An output from the step 1 is the cluster dendrogram

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A Review of the R Graphics Cookbook

February 11, 2013
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A Review of the R Graphics Cookbook

A common criticism of R, especially from data scientists who are new to R but proficient in multiple programming languages, is that R is “quirky” and annoying because there is almost always more than one way to do simple things. I usually counter that they are trying to say that R is “flexible” and “rich”, but by the time...

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R package building automation

February 11, 2013
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Title: R package building automationInspired by the post at http://giventhedata.blogspot.tw/2013/02/my-r-package-development-cheat-sheet.html. I have decided to publish my cheat script for package development as well. Building package used to be a nightmare, filling in all those Rdfiles manually can cause some serious brain...

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analyze health professional shortage areas (hpsa) with r

February 11, 2013
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a health professional shortage area (hpsa) is a geographic area, population group, or health care facility that has been designated by the united states government as having an insufficient supply of medical providers, based on certain provider-to-popu...

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Using R: accessing PANTHER classifications

February 10, 2013
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Using R: accessing PANTHER classifications

Importing, subsetting, merging and exporting various text files with annotation (in the wide sense, i.e. anything that might help when interpreting your experiment) is not computation and it’s not biology either, but it’s housekeeping that needs to be done. Everyone has a weapon of choice for general-purpose scripting and mine is R. Yes, this is

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Finding Patterns Amongst Binary Variables with the homals Package

February 10, 2013
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Finding Patterns Amongst Binary Variables with the homals Package

It’s survey analysis season for me at work!  When analyzing survey data, the one kind of analysis I have realized that I’m not used to doing is finding patterns in binary data.  In other words, if I have a question … Continue reading →

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Happy Birthday Florence Henderson

February 9, 2013
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Happy Birthday Florence Henderson

As a celebration of Florence Henderson’s 79th birthday (on February 14), I have created this scatterplot to use in my regression course. The plot depicts the relationship between time spent on mathematics homework outside of school (expressed as z-scores) and … Continue reading →

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