Posts Tagged ‘ visualization ’

QQ plot of p-values in R using base graphics

July 14, 2010
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Update Tuesday, September 14, 2010: Fixed the ylim issue, now it sets the y axis limit based on the smallest observed p-value.A while back Will showed you how to create QQ plots of p-values in Stata and in R using the now-deprecated sma package. A bi...

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Draw a trophic network with n levels

July 6, 2010
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In the last few weeks, I started focusing more on more of trophic systems with three levels or more. I wanted something to visualize the resulting trophic network, so I came up with a little R function called draw.mnet (which stands for draw a multiple-levels network).

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Visualization of regression coefficients (in R)

July 2, 2010
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Visualization of regression coefficients (in R)

Update (07.07.10): The function in this post has a more mature version in the “arm” package. See at the end of this post for more details. * * * * Imagine you want to give a presentation or report of your latest findings running some sort of regression analysis. How would you do it? This was exactly the question...

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Clustergram: visualization and diagnostics for cluster analysis (R code)

June 15, 2010
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Clustergram: visualization and diagnostics for cluster analysis (R code)

About Clustergrams In 2002, Matthias Schonlau published in “The Stata Journal” an article named “The Clustergram: A graph for visualizing hierarchical and . As explained in the abstract: In hierarchical cluster analysis dendrogram graphs are used to visualize how clusters are formed. I propose an alternative graph named “clustergram” to examine how cluster members are assigned to clusters as...

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Tracking JAXA Arctic Sea Ice Extent Trends

June 3, 2010
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Tracking JAXA Arctic Sea Ice Extent Trends

See my Arctic Update Page for daily updates on Arctic Sea Ice Extent Arctic Sea Ice Extent (SIE) follows an annual cycle, with maximum levels usually in March and minimum values in September.  Many analysts use day-of-year charts to compare … Co...

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Canadian CPI: Visualization Brainstorm

May 27, 2010
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After finishing the R prototype for data visualization, I've started abstracting the various methods necessary to create beautiful graphs. While there's no preliminary version of the R package yet, I think I've taken a number of exciting steps. These include: Abstracting graph objects. Objects such as lines, scatter plots, and other graph types can all

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Prototype: Web-Friendly Visualizations in R

May 18, 2010
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Developing web-friendly data visualizations is not very difficult, though as far as I know, a package that allows one to do this directly in R does not exist (e-mail me if you know of one). As someone who has been developing lots of data-oriented software tools, it's always nice to post visualizations online. To facilitate

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The new GUI for ggplot2 (using Deducer) – the designer wants your opinion

May 1, 2010
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After discovering that R is expected (this summer) to have a GUI for ggplot2 (through deducer), I later found Ian’s gsoc proposal for this GUI.  Since the system is in it’s early stages of development, Ian has invited people to give comments, input and critique on his plans for the project. For your convenience (and with Ian’s permission), I...

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Jeroen Ooms’s ggplot2 web interface – a new version released (V0.2)

April 12, 2010
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Good news. Jeroen Ooms released a new version of his (amazing) online ggplot2 web interface: yeroon.net/ggplot2 is a web interface for Hadley Wickham’s R package ggplot2. It is used as a tool for rapid prototyping, exploratory graphical analysis and education of statistics and R. The interface is written completely in javascript, therefore there is no need to install anything on the...

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Correlation scatter-plot matrix for ordered-categorical data

April 7, 2010
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Correlation scatter-plot matrix for ordered-categorical data

When analyzing a questionnaire, one often wants to view the correlation between two or more Likert questionnaire item’s (for example: two ordered categorical vectors ranging from 1 to 5). When dealing with several such Likert variable’s, a clear presentation of all the pairwise relation’s between our variable can be achieved by inspecting the (Spearman) correlation matrix (easily achieved in R...

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