2081 search results for "ggplot"

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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Finding a jump in data

February 9, 2013
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Finding a jump in data

The other day I saw a plot with some data with a clear jump in it. So I wondered if it were possible to determine the position of that jump. Data with a jump is easy enough made:library(ggplot2)n <- 100mydata <- data.frame(x=runif(n))mydata$...

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Learning R Using a Chemical Reaction Engineering Book: Part 4

February 8, 2013
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Learning R Using a Chemical Reaction Engineering Book: Part 4

The links to previous parts are listed here. (Part 1, Part 2, Part 3). In this part, I tried to recreate the examples in sections A.3.1 of the computational appendix in the reaction engineering book (by Rawlings and Ekerdt). Solving a … Continue reading →

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Getting staRted with R.

February 7, 2013
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Getting staRted with R.

As a PhD student and researcher, I often hear friends and colleagues say that they want to learn R, but that the learning curve is so steep that they can't seem to get started.  It's true that learning any tool as powerful as R can be confusing at...

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Relearn boxplot and label the outliers

February 5, 2013
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Relearn boxplot and label the outliers

Despite the fact that box plot is used almost every where and taught at undergraduate statistic classes, I recently had to re-learn the box plot in order to know how to label the outliers.This stackoverflow post was where I found how...

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For descriptive statistics, values below LLOQ set to …

February 3, 2013
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For descriptive statistics, values below LLOQ set to …

That is what I read the other day. For calculation of descriptive statistics, values below the LLOQ (lower limit of quantification)  were set to.... Then I wondered, wasn't there a trick in JAGS to incorporate the presence of missing data while es...

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Scatterplot with marginal boxplots

February 3, 2013
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Scatterplot with marginal boxplots

Using R and ggplot2 to draw a scatterplot with the two marginal boxplotsDrawing a scatterplot with the marginal boxplots (or marginal histograms or marginal density plots) has always been a bit tricky (well for me anyway). The approach I take here is, first, to draw the three separate plots using ggplot2:the scatterplot;the horizontal boxplot to appear in the...

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A slightly different introduction to R, part III

February 2, 2013
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A slightly different introduction to R, part III

I think you’ve noticed by now that a normal interactive R session is quite messy. If you don’t believe me, try playing around for a while and then give the history() command, which will show you the commands you’ve typed. If you’re anything like me, a lot of them are malformed attempts that generated some

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Taking Expectations to the Next Level

January 31, 2013
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Taking Expectations to the Next Level

Higher Expectations I came across this post on Thursday and found it to be quite interesting. Clearly rental prices vary according to where you live. That isn't too surprising. I started thinking a bit more about it and thought that Boston and the nearby communities would have to...

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Using Line Segments to Compare Values in R

January 31, 2013
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Using Line Segments to Compare Values in R

Sometimes you want to create a graph that will allow the viewer to see in one glance:The original value of a variableThe new value of the variableThe change between old and newOne method I like to use to do this is using geom_segment and geom_poin...

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