# Blog Archives

## A Talk About Campaign Finance in Brazil

October 16, 2015
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Last week, I delivered a talk at University of Brasilia about my past research on the topic of campaign finance. I didn’t know in advance about the existence of this seminar. Indeed, it was a big surprise receiving the invitation from Prof. Marcelo Pimentel, who is teaching on Fridays afternoon a class on this topic with more than 50...

## Understanding Margin of Error for Small Populations

October 13, 2015
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I got an email today inquiring if the margin of error reported in the newest poll by Datafolha would possibly be misleading. The polling firm often report surveys with regular sizes (1000/2400), so the margin of error calculated is in the range of +/-2% to +/-3%. However, in the latest pool, the pollster sampled 340 congressmen, reporting a...

## The butterfly curve

October 6, 2015
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I came across the butterfly curve, which was discovered by Temple Fay. The butterfly curve is produced by a parametric equation where: x = sin(t) * (e^cos(t)-2cos(λt)-sin(t/12)^5)and y = cos(t) * (e^cos(t)-2cos(λt)-sin(t/12)^5). Where t stands for time and λ for a user input variable. library(ggplot2) source("https://raw.githubusercontent.com/danielmarcelino/SciencesPo/master/R/butterfly.R") p4 = butterfly(100, 1000, title="100 x 1000") Date of Analysis: Wed Oct 07 2015 Computation time: 0.01444697 —————————————————

## Isn’t sad that all that matters in an election is the candidate’s height?

September 15, 2015
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I came across the claim in the US press suggesting that the taller the candidate, the better his/her chances for success in presidential elections. After a little search, I found this Wikipedia entry, and even some academic research on the issue, mainly relating this phenomenon to some sort of evolutionary instinctual preference. At least in the US,...

## Spatstat – An introduction and measurements with Bio7

September 10, 2015
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10.09.2015 Here I present a summary of a small spatstat workshop I created. I also explain in several videos how to transfer and convert 2d and 3D ImageJ measurements to a spatial point pattern with Bio7. The example datasets and code samples used here were taken from the spatstat help and from spatstat scripts cited

## Bio7 2.3 Released!

August 28, 2015
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28.08.2015 As a result of the useR conference 2015 with fantastic workshops and presentations where I also presented my software I released a new version of Bio7 with many improvements and new features inspired by the R conference and important for the next ImageJ conference 2015 where I will give a Bio7 workshop. For this

## Argentine general election, 2015

August 6, 2015
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The 2015 Argentine’s presidential election to be held next October 25th is approaching and the dispute begun to appear more clearly since the major parties announced their potential candidates last June. This Sunday, the political parties are holding their primaries for the upcoming presidential election. As in US, in Argentine the primaries are important for parties to solve internal disputes,...

## ImageJ Selections to Georeferenced Spatial Objects

August 5, 2015
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05.08.2015 As a result of the last UseR conference and some great spatial workshops and talks where I participated I decided to rework the selection dialog for the upcoming Bio7 2.3 to transfer ImageJ selection data as ‘Spatial Objects’ with the help of the package ‘sp‘ and the Java GDAL binding (version 1.7.1). Video: One

## Ternary plots in politics

August 3, 2015
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This week, I read a post by Nicholas Hamilton about ternary plots that made me think, how this geometric diagram has many different application in science fields. Couple weeks ago, I was reading a book by Donald Saari, who uses ternary charts massively to project election outcomes in different electoral settings. Perhaps, most common, ternary diagrams are used for...

## The Greek thing

July 3, 2015
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Greeks have been quite volatile on their opinion whether they should accept or not a proposal by the country’s creditors for more austerity to keep aid flowing. The polls conducted over this week look like crazy, though that “belly” was likely provoked by the anxiety on what comes next after Greece not paying IMF back. The data were...