2636 search results for "GIS"

Incompetence borne of excessive cleverness

April 29, 2012
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I have just got back from the 24 hour Data Science Global Hackathon; I was an on-site participant at Hub Westminster in London (thanks to Carlos and his team for doing such a great job looking after us all {around 50 turned up from the 100 who registered; the percentage was similar in other cities

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Marriage is good for your income

April 29, 2012
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For those of you who are into machine learning, here you can find a cool collection of databases to play around with your favorite algorithm. I choose one out of the available 200 and fit a logistic regression model. The idea … Continue reading → Related posts: What is important for a loan?...

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Guess who wins: apply() versus for loops in R

April 28, 2012
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Guess who wins: apply() versus for loops in R

Yesterday I tried to do some data processing on my really big data set in MS Excel. Wow, did it not like handling all those data!! Every time I tried to click on a different ribbon, the screen didn’t even … Continue reading →

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R Workshop: Reproducible Research using Sweave for Beginers

April 27, 2012
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R Workshop: Reproducible Research using Sweave for Beginers

Monday, April 30, 2012  14h-16h. Stewart Biology Rm w6/12 (Montreal) guRu: Denis Haine (Université de Montréal) Topics Reproducible research was first coined by Pr. Jon Claerbout, professor of geophysics at Stanford University, to describe that the results from researches can be replicated by other scientists by making available data, procedures, materials and the computational environment

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How to download complete XML records from PubMed and extract data

April 27, 2012
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How to download complete XML records from PubMed and extract data

Yesterday I wrote an article that looked at the top 20 Cognitive Behavior Therapy journals with the most publications; today I will explain how I did it with R.

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Real Time Structural Break

April 27, 2012
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Real Time Structural Break

Yesterday as I played with bfast I kept thinking “Yes, but this is all in hindsight.  How can I potentially use this in a system?”  Fortunately, one of the fine authors very generously commented on my post Structural Breaks (Bull or Bear?...

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Measuring user retention using cohort analysis with R

April 27, 2012
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Measuring user retention using cohort analysis with R

Cohort analysis is super important if you want to know if your service is in fact a leaky bucket despite nice growth of absolute numbers. There’s a good write up on that subject “Cohorts, Retention, Churn, ARPU” by Matt Johnson. So how to do it using R and how to visualize it. Inspired by examples

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Randomization thoughts

April 27, 2012
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Randomization thoughts

Le Grand Casino of Monte CarloOn Monday I’m going to be leading a little stats workshop on randomization tests and null models. In preparation for this I wrote up code for null model examples I wanted to write a post that introduced the basics of these models (Null models, bootstrapping,...

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Structural Breaks (Bull or Bear?)

April 26, 2012
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Structural Breaks (Bull or Bear?)

When I spotted the bfast R package, I could not resist attempting to apply it to identify bull and bear markets.  For all the details that I do not understand, please see the references: Jan Verbesselt, Rob Hyndman, Glenn Newnham, Darius Culvenor...

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Graphic Parameters (symbols, line types, and colors) for ggplot2

April 26, 2012
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Graphic Parameters (symbols, line types, and colors) for ggplot2

Following up on John Mount’s post on remembering symbol parameters in ggplot2, I decided to give it a try and included symbols, line types, and colors (based upon Earl Glynn’s wonderful color chart).  Code follows below.    

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