Publications by Michael kao

R package building automation

11.02.2013

Title: R package building automation Inspired 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 damage. Thanks to the...

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Violin plots and regional income distribution

20.03.2013

While preparing my slides for statistical graphics, a plot really caught my eye when I was playing around with the data. I started off by plotting the time seriesof GNI per capita by country, and as expected it got quite messy and incomprehensible. ## Download and manipulate the data library(FAOSTAT) raw.lst = getWDItoSYB(indicator = c("NY.GNP.P...

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Tupper’s self-referential formula

24.03.2013

Can't remember where I first came across this equation but the Tupper's self referential equation, is a very interesting formula that when graphed in two dimension plane it reproduces the formula. \[ \frac{1}{2} < \left\lfloor \bmod\left(\left\lfloor\frac{y}{17}\right\rfloor2^{-17\lfloor x\rfloor - \bmod(\lfloor y \rfloor, 17)}, 2\right)\right\...

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First day of State of Food Insecurity (SOFI) 2013

02.10.2013

The FAO flagship publication SOFI 2013 was release yesterday on the 1st of October, the publication is the most important report in monitoring the progress towards the 2015 Millenium Development Goal and ultimately eliminate hunger. I was interest in how the people responded, so I scrapped some data from Twitter and previous work to carry out s...

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Accurate imputation and valid statistical inference with ensemble

25.01.2014

Imputation is predictive inference and not causal inference! I have met many people, who consider the two are equivalent. Their reasoning is based on the belief that if you can produce a model which replicate the data generating mechanism, it will give you the best prediction. Which may or may not be true depending on your philosophy of math...

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Why multiple imputation?

20.03.2014

BackgroundIn the forth coming week, I will be giving a presentation on the fundamentals of imputation to my colleagues. One of the most important idea I would like to present is multiple imputation. In my last post, I have given a small example of multiple imputation, but it does not provide the evidence why we should use it. This is the aim o...

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Spline interpolation of temporal resolution for satellite images.

25.08.2014

This week, I had a discussion with a few of my colleagues on the possibility of utilizing remote sensing data or satellite images to improve our statistical estimation such as imputation. One source of interest is the Normalized Difference Vegetation Index which quantify the concentrations of green leaf vegetation around the globe. More detail...

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3D Sine Wave

16.09.2014

Had a headache last night, so decided to take things easy and just read posts Google+. Then I came across this post which seems interesting so I thought I would play around before I head to bed. First of all, I thought generating a square base would be much easier in R compare to hexagons. Starting with 2 numeric vectors and then expand them ...

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