2807 search results for "GIS"

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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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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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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Exposure with binomial responses

February 9, 2013
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Exposure with binomial responses

Last week, we’ve seen how to take into account the exposure to compute nonparametric estimators of several quantities (empirical means, and empirical variances) incorporating exposure. Let us see what can be done if we want to model a binomial response. The model here is the following: , the number of claims  on the period  is unobserved the number of...

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PID Control-R

February 8, 2013
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PID Control-R

On a whim, I thought it might be fun to try to implement a PID control algorithm ... in R.Yes, I know I have a strange idea of fun.BackgroundPID control is a heuristic method of automatically controlling processes as wide ranging as water levels in tan...

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Retrieve IP ASN & BGP Peer Info With R

February 7, 2013
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Retrieve IP ASN & BGP Peer Info With R

This is part of a larger project I’m working on, but it’s useful enough to share (github version coming soon). The fine folks at @TeamCymru have a great service to map IP addresses to ASN/BGP information en masse. There are libraries for Python, Perl and other languages but none for R (that I could find).

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R User Group Meetings in Switzerland and London

February 7, 2013
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Mango Solutions is pleased to confirm details of two forthcoming  R User Group Meetings:  BaselR Date:                                     21st Feb 2013 Venue:                                 transBARent, Viaduktsrasse 3, CH 4051 Basel, Switzerland Time:                                     6.30 pm – 9.30pm Presentations:                  Kinetic evaluations of environmental metabolism data for the agrochemical industry using R – Johannes Ranke                   Estimating Switzerland’s quarterly GDP in R-...

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My R-Package Development Cheat Sheet

February 7, 2013
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In case you have no experience in writing an R-package yourself  but would like to start developing one right away, this post might be helpful.I'm about to finish my first own (serious) R-package these days (more on the package itself later). Whil...

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Ryan Peek on using xts and ggplot for time-series data

February 6, 2013
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Ryan Peek on using xts and ggplot for time-series data

At Davis R Users’ Group today, Ryan Peek gave a presentation on how he takes data from his field instruments and visualizes it in R. Here are his notes. The original *.Rmd file and data can be found here SHORT HOW-TO ON USING XTS AND GGPLOT FOR TIME SERIES DATA XTS is a very helpful package...

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Set operations on more than two sets in R

February 6, 2013
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ProblemSet operations are a common place thing to do in R, and the enabling functions in the base stats package are:intersect(x, y)union(x, y)setdiff(x, y)setequal(x, y)That said, you'll note that each ONLY takes two arguments - i.e. set X and set Y - ...

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