Lose the base, connect the dot, and confuse the message

May 21, 2013
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Lose the base, connect the dot, and confuse the message

Reader Jack S. sent over this chart (link): The first problem readers encounter with this image is "What is MMI?" I like to think of any presentation as a set of tearout pages. Even if the image is part of...

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Slide: one function for lag/lead variables in data frames, including time-series cross-sectional data

May 21, 2013
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I often want to quickly create a lag or lead variable in an R data frame. Sometimes I also want to create the lag or lead variable for different groups in a data frame, for example, if I want to lag GDP for each country in a data frame. I've found ...

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An R debugging example

May 21, 2013
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The steps taken to fix an R problem. Task To prepare for the Portfolio Probe blog post called “Implied alpha and minimum variance”, I tried to update a matrix of daily stock prices using a function I had written for the purpose. Error When I tried to do what I wanted, I got: > univclose130518 […] The post An R debugging example appeared first on Burns Statistics.

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Don’t be misguided by the beauty of mathematics, if the data tells you otherwise

May 21, 2013
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Don’t be misguided by the beauty of mathematics, if the data tells you otherwise

I was trained as a mathematician and it was only last year, when I attended the Royal Statistical Society conference and met many statisticians that I understood how different the two groups are. In mathematics you often start with some axioms, things...

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Bayes Pharma 2013 (1)

May 20, 2013
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Earlier today, I've arrived in Rotterdam for the Bayes Pharma conference. As I already said in a previous post, I think we have quite an exciting line up. In fact, I think that the finalised programme is packed with interesting talks!My first impressio...

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R/Finance 2013 slides

May 20, 2013
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R/Finance 2013 slides

I have just returned from the R/Finance conference and want to share with you my slides and examples. The Cluster Risk Parity portfolio allocation method is an example of Cluster Portfolio Allocation methods that focuses on diversification or more specifically diversification of your risk bets. (i.e. portfolio that distributes risk equally both within clusters and […]

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More on Chutes & Ladders

May 20, 2013
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More on Chutes & Ladders

Matt Maenner asked about the sawtooth pattern in the figure in my last post on Chutes & Ladders. Damn you, Matt! I thought I was done with this. Don’t feed my obsession. My response was that if the game ends early, it’s even more likely that it’ll be the kid who went first who won. […]

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Model fitting exam problem

May 20, 2013
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Recently I have run an exam where the following question had risen many problems for students (here I give its shortened formulation). You are given the data generating process y = 10x + e, where e is error term. Fit linear regression using lm, ne...

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qdap 0.2.2 released

May 20, 2013
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qdap 0.2.2 released

I’m very pleased to announce the release of qdap 0.2.2 This is the third installment of the qdap package available at CRAN. The qdap package automates many of the tasks associated with quantitative discourse analysis of transcripts containing discourse, including … Continue reading →

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Evaluating Columbia University’s Frontiers of Science course

May 20, 2013
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Frontiers of Science is a course offered as part of Columbia University’s Core Curriculum. The course is controversial, with some people praising its overview of several areas of science, and others feeling that a more traditional set of introductory science courses would do the job better. Last month, the faculty in charge of the course [...]The post Evaluating Columbia University’s Frontiers of Science course appeared first on Statistical Modeling, Causal…

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What happened that the journal Psychological Science published a paper with no identifiable strengths?

May 20, 2013
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The other day we discussed that paper on ovulation and voting (you may recall that the authors reported a scattered bunch of comparisons, significance tests, and p-values, and I recommended that they would’ve done better to simply report complete summaries of their data, so that readers could see the comparisons of interest in full context), [...]The post What happened that the journal Psychological Science published a paper with no identifiable…

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Ways to multiply in the SAS/IML language

May 20, 2013
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Ways to multiply in the SAS/IML language

For programmers who are learning the SAS/IML language, it is sometimes confusing that there are two kinds of multiplication operators, whereas in the SAS DATA step there is only scalar multiplication. This article describes the multiplication operators in the SAS/IML language and how to use them to perform common tasks [...]

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Implied alpha and minimum variance

May 20, 2013
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Implied alpha and minimum variance

Under the covers of strange bedfellows. Previously The idea of implied alpha was introduced in “Implied alpha — almost wordless”. In a comment to that post Jeff noticed that the optimal portfolio given for the example is ever so close to the minimum variance portfolio.  That is because there is a problem with the example … Continue reading →

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When Does the Kinetic Theory of Gases Fail? Examining its Postulates with Assistance from Simple Linear Regression in R

When Does the Kinetic Theory of Gases Fail?  Examining its Postulates with Assistance from Simple Linear Regression in R

Introduction The Ideal Gas Law, , is a very simple yet useful relationship that describes the behaviours of many gases pretty well in many situations.  It is “Ideal” because it makes some assumptions about gas particles that make the math and the physics easy to work with; in fact, the simplicity that arises from these […]

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Mayo: Meanderings on the Onto-Methodology Conference

May 20, 2013
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Mayo: Meanderings on the Onto-Methodology Conference

Writing a blog like this, a strange and often puzzling exercise[1], does offer a forum for sharing half-baked chicken-scratchings from the back of frayed pages on themes from our Onto-Meth[2] conference from two weeks ago[3]. (The previous post had notes from blogger and attendee, Gandenberger.) Several of the talks reflect a push-back against the idea that […]

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qdap 0.2.2 released

May 20, 2013
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qdap 0.2.2 released

I’m very pleased to announce the release of qdap 0.2.2 This is the third installment of the qdap package available at CRAN. The qdap package automates many of the tasks associated with quantitative discourse analysis of transcripts containing discourse, including … Continue reading →

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Playing cards in Vegas?

May 20, 2013
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Playing cards in Vegas?

In a previous post, a few weeks ago, I mentioned that I will be in Las Vegas by the end of July. And I took the opportunity to write a post on roulette(s). Since some colleagues told me I should take some time to play poker there, I guess I have to understand how to play poker… so I went back to basics on cards, and shuffling techniques. Now, I…

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Pedagogical Content Knowledge

May 19, 2013
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Pedagogical Content Knowledge

Pedagogical content knowledge for Statistics Pedagogical content knowledge means knowing how to teach a specific subject, discipline or context. There is a school of thought that the skill of teaching is transferable between subjects, so long as the teacher knows … Continue reading →

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Numerical optimizers for Logistic Regression

May 19, 2013
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Numerical optimizers for Logistic Regression

Following a challenge proposed by Gael to my group I compared several implementations of Logistic Regression. The task was to implement a Logistic Regression model using standard optimization tools from scipy.optimize and compare them against state of ...

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Exploratory Data Analysis – Computing Descriptive Statistics in R for Data on Ozone Pollution in New York City

Exploratory Data Analysis – Computing Descriptive Statistics in R for Data on Ozone Pollution in New York City

Introduction This is the first of a series of posts on exploratory data analysis (EDA).  This post will calculate the common summary statistics of a univariate continuous data set – the data on ozone pollution in New York City that is part of the built-in “airquality” data set in R.  This is a particularly good data set […]

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Sunday data/statistics link roundup (5/19/2013)

May 19, 2013
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This is a ridiculously good post on 20th versus 21st century problems and the rise of the importance of empirical science. I particularly like the discussion of what it means to be a "solved" problem and how that has changed. … Continue reading →

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Prose is paragraphs, prose is sentences

May 19, 2013
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Prose is paragraphs, prose is sentences

This isn’t quite right—poetry, too, can be in paragraph form (see Auden, for example, or Frost, or lots of other examples)—but Basbøll is on to something here. I’m reminded of Nicholson Baker’s hilarious “From the I...

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Sharing my R notes

May 19, 2013
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Sharing my R notes

I started working with R 2 1/2 years ago. I remember opening R closing it and thinking it was the dumbest thing ever (command line to a non programmer is not inviting). Now it’s my constant friend. From the beginning … Continue reading →

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