2449 search results for "gis"

Modeling Trick: Masked Variables

July 1, 2012
By
Modeling Trick: Masked Variables

A primary problem data scientists face again and again is: how to properly adapt or treat variables so they are best possible components of a regression. Some analysts at this point delegate control to a shape choosing system like neural nets. I feel such a choice gives up far too much statistical rigor, transparency and Related posts:

Read more »

Rchievement of the day #3: Bloggin’ from R

July 1, 2012
By
Rchievement of the day #3: Bloggin’ from R

I have become a complete knitr addict of late and have been using it in combination with RStudio’s R markdown support on a regular basis. In fact I wrote this post using it! It then dawned on me how great it would be if I … Continue reading →

Read more »

igraph and SNA: an amateur’s dabbling

June 29, 2012
By
igraph and SNA: an amateur’s dabbling

I’ve been playing with the igraph package a bit lately (see previous post HERE) and wanted to approach a problem I once visited in the past. The basic gist of the problem is this: Students in a class are asked … Continue reading →

Read more »

Horizon Plot Already Available

June 29, 2012
By
Horizon Plot Already Available

When I wrote Cubism Horizon Charts in R, I should have known that horizon plot functionality already exists in R http://rgm2.lab.nig.ac.jp/RGM2/func.php?rd_id=latticeExtra:horizonplot and in this case in one of my already favorite packages latticeExtra...

Read more »

multiplicitiesoffreedom demonstrates Chaos Theory in Excel. If…

June 29, 2012
By
multiplicitiesoffreedom demonstrates Chaos Theory in Excel. If…

multiplicitiesoffreedom demonstrates Chaos Theory in Excel. If he filled in more initial values, you would see a thick bar—like a picture of white-noise.Butterflies flapping their wings in Vermont to change the wind in Hangzhou? A drop of water on ...

Read more »

impacTwit : How big is your work on twitter?

June 29, 2012
By
impacTwit : How big is your work on twitter?

There’s a great Tom Waits song from the album “Mule Variations” called “Big in Japan”. The beauty of saying you’re big in Japan is that no one can ever really verify the statement (or at least that was more true in 1999). You might assert “my work is big on twitter”, and hey, how would I know?...

Read more »

Big Data Generalized Linear Models with Revolution R Enterprise

June 28, 2012
By
Big Data Generalized Linear Models with Revolution R Enterprise

R''s glm function for generalized linear modeling is very powerful and flexible: it supports all of the standard model types (binomial/logistic, Gamma, Poisson, etc.) and in fact you can fit any distribution in the exponential family (with the family argument). But if you want to use it on a data set with millions or rows, and especially with more...

Read more »

Effect of sample size on the accuracy of Cohen’s d estimates (95 % CI)

June 27, 2012
By
Effect of sample size on the accuracy of Cohen’s d estimates (95 % CI)

When talking about confidence intervals, Jacob Cohen famously said: “I suspect that the main reason they are not reported is that they are so embarrassingly large!” (Cohen, 1994). In this post I'll take a look at the relationship between the 95 % CI for Cohen's d and it's corresponding sample size.

Read more »

Crazy RUT in Academic Context Why Trend is Not Your Friend

June 26, 2012
By
Crazy RUT in Academic Context Why Trend is Not Your Friend

In response to Where are the Fat Tails?, reader vonjd very helpfully referred me to this paper The Trend is Not Your Friend! Why Empirical Timing Success is Determined by the Underlying’s Price Characteristics and Market Efficiency is Irrelevant by P...

Read more »

useR 2012: main conference braindump

June 24, 2012
By
useR 2012: main conference braindump

I knew R was versatile, but DANG, people do a lot with it: > > … I don’t think anyone actually believes that R is designed to make *everyone* happy. For me, R does about 99% of the things I … Continue reading →

Read more »