1641 search results for "time series"

The distribution of financial returns made simple

January 23, 2012
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The distribution of financial returns made simple

Why returns have a stable distribution As “A tale of two returns” points out, the log return of a long period of time is the sum of the log returns of the shorter periods within the long period. The log return over a year is the sum of the daily log returns in the year.  … Continue reading...

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Gold price and fear

January 18, 2012
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Gold price and fear

Via @theEconomist, I understood that there might be connections between the price of Gold (which is said to be extremely high nowadays) and the VIX SP500 index (the option volatility index, i.e. the so-called "fear index", as discussed - in French-...

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A slice of S&P 500 skewness history

January 16, 2012
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A slice of S&P 500 skewness history

How symmetric are the returns of the S&P 500? How does the skewness change over time? Previously We looked at the predictability of kurtosis and skewness in S&P constituents.  We didn’t see any predictability of skewness among the constituents.  Here we look at skewness from a different angle. The data Daily log returns of the … Continue reading...

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Moving window filters and the pracma package

Moving window filters and the pracma package

In my last post, I discussed the Hampel filter, a useful moving window nonlinear data cleaning filter that is available in the R package pracma.  In this post, I briefly discuss this moving window filter in a little more detail, focusing on two important practical points: the choice of the filter’s local outlier detection threshold, and the question of...

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Functional ANOVA using INLA

January 13, 2012
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Functional ANOVA using INLA

Ramsay and Silverman’s Functional Data Analysis is a tremendously useful book that deserves to be more widely known. It’s full of ideas of neat things one can do when part of a dataset can be viewed as a set of

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Example 9.19: Demonstrating the central limit theorem

January 11, 2012
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Example 9.19: Demonstrating the central limit theorem

A colleague recently asked "why should the average get closer to the mean when we increase the sample size?" We should interpret this question as asking why the standard error of the mean gets smaller as n increases. The central limit theorem shows t...

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Harmonic means, again again

January 9, 2012
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Harmonic means, again again

Another arXiv posting I had had no time to comment is Nial Friel’s and Jason Wyse’s “Estimating the model evidence: a review“. This is a review in the spirit of two of our papers, “Importance sampling methods for Bayesian discrimination between embedded models” with Jean-Michel Marin (published in Jim Berger Feitschrift, Frontiers of Statistical Decision

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Extreme Bond Returns

January 6, 2012
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Extreme Bond Returns

20 years of data is nowhere near enough to satisfy my insatiable appetite for bigger datasets.  While I showed Record Long Term Treasury Returns with Vanguard’s US Long Treasury mutual fund, its 20 year life is not sufficient to give me comfort ...

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Plotting Doctor Who Ratings (1963-2011) with R

January 3, 2012
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Plotting Doctor Who Ratings (1963-2011) with R

Introduction First day back to work after New Year celebrations and my brain doesn’t really want to think too much. So I went out for lunch and had a nice walk in the park. Still had 15 minutes to kill before my lunch break was over and so decided to kill some time with a quick web

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Voting Networks in the Danish Parliament

January 2, 2012
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Voting Networks in the Danish Parliament

One of my Christmas presents was the book Beautiful Visualization. Chapter 8 by Andrew Odewahn is a very nice piece on visualizing the U.S Senate social graph. Odewahn basically builds an affinity network, where ties represent whether two senator have ...

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