1928 search results for "time series"

Fast-track publishing using knitr: stitching it together (part V)

January 20, 2014
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Fast-track publishing using knitr: stitching it together (part V)

Fast-track publishing using knitr is a short series on how I use knitr to speedup publishing in my research. There has been plenty of feedback and interest for the series, and in this post I would like to provide (1) a brief summary and (2) an example showing how to put all the pieces together. [caption id="attachment_1094"...

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Rectangular Integration (a.k.a. The Midpoint Rule)

Rectangular Integration (a.k.a. The Midpoint Rule)

Introduction Continuing on the recently born series on numerical integration, this post will introduce rectangular integration.  I will describe the concept behind rectangular integration, show a function in R for how to do it, and use it to check that the distribution actually integrates to 1 over its support set.  This post follows from my

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Statistics meets rhetoric: A text analysis of "I Have a Dream" in R

January 20, 2014
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Statistics meets rhetoric: A text analysis of "I Have a Dream" in R

This article was first published on analyze stuff. It has been contributed to Anything but R-bitrary as the second article in its introductory series.By Max Ghenis Today, we celebrate the would-be 85th birthday of Martin Luther King, Jr., a man remembered for pioneering the civil rights movement through his courage, moral leadership, and oratory prowess. This post...

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Second NYC R classes(announcement and teaching experience)

January 20, 2014
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Second NYC R classes(announcement and teaching experience)

(The photo was from our first offering of R classes) We are going to offer our Data Science by R (beginner level) course again in February. The goal of this class is to get students to a point where they are self-sufficient in R, are proficient at analyzing data and can take these skills back to their full-time jobs....

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What is volatility?

January 19, 2014
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What is volatility?

Some facts and some speculation. Definition Volatility is the annualized standard deviation of returns — it is often expressed in percent. A volatility of 20 means that there is about a one-third probability that an asset’s price a year from now will have fallen or risen by more than 20% from its present value. In … Continue reading...

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Fast-track publishing using knitr: table mania (part IV)

January 15, 2014
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Fast-track publishing using knitr: table mania (part IV)

Fast-track publishing using knitr is a short series on how I use knitr to speedup publishing in my research. While illustrations (previous post) are optional, tables are not, and this fourth article is therefore devoted to tables. Tables through knitr is probably one of the most powerful fast-track publishing tools, in this article I will show (1) how...

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Butterworth filter overshoot

January 15, 2014
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Butterworth filter overshoot

Introduction Butterworth filters with order other than 1 have an overshoot phenomenon that can be problematic in some cases. For example, if smoothing is used on an estimate of kinetic energy, overshoots might yield negative values that are nonphysical. This post simply illustrates this with made-up data that the reader can experiment with. Methods First, create and plot...

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Smoothing CTD profiles

January 11, 2014
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Smoothing CTD profiles

Introduction Smoothing hydrographic profiles with conventional time-series methods is problematic for two reasons: (a) the data are commonly not equi-spaced in depth and (b) the data seldom lack trends in depth. The issues and their solutions are illustrated without much discussion here. The first step in making the graph shown above is to load the oce library and...

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Summarising multivariate palaeoenvironmental data

January 9, 2014
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Summarising multivariate palaeoenvironmental data

The horseshoe effect is a well known and discussed issue with principal component analysis (PCA) (e.g. Goodall 1954; Swan 1970; Noy-Meir & Austin 1970). Similar geometric artefacts also affect correspondence analysis (CA). In part 1 of this series I looked at the implications of these “artefacts” for the recovery of temporal or single dominant gradients from multivariate palaeoecological data....

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Fast-track publishing using knitr: exporting images for sharing and press (part III)

January 7, 2014
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Fast-track publishing using knitr: exporting images for sharing and press (part III)

(This article was first published on G-Forge » R, and kindly contributed to R-bloggers) Images can be a powerful medium if used right. The image is CC by alemdag. Fast-track publishing using knitr is a short series on how I use knitr to speedup publishing in my research. This is the third article in the series devoted to plots....

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