890 search results for "how to import image file to r"

Fitting a dynamic model, and determining the number of parameters that can be fitted.

July 8, 2012
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Fitting a dynamic model, and determining the number of parameters that can be fitted.

Let's suppose that we have the same dynamic model we presented before - that is, the Lorentz system of differential equations. Remember? In order to perform a fitting we need to define an objective function of sort: this will then be minimised. Now,...

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SMS analysis (coming from an Android smartphone or an IPhone)

July 7, 2012
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SMS analysis (coming from an Android smartphone or an IPhone)

At first, this post was intended to describe how to manipulate dates with R but, as the idea was coming from the question of one of my students who wanted to analyze his SMS, I thought that I might as well also explain the whole analysis process... Using my new smartphone (that I started to

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R, knitr & markdown = HTML

July 7, 2012
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R, knitr & markdown = HTML

Welcome to this demo of how R code and results can be combined into an HTML report. This entire blogpost was generated by using a combination of R, knitr and markdown. Beforehand, make sure you have the following libraries installed (latest version); knitr markdown ggplot2 (to run the example script)  Read more »

Alternative to Monte Carlo Testing

July 4, 2012
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Alternative to Monte Carlo Testing

When we backtest a strategy on a portfolio, it is a simple analysis of a single period in time. There are ways to “stress test” a strategy such as monte carlo, random portfolios, or shuffling the returns in a random order. I could never really wrap my head around monte carlo and shuffling the returns … Continue reading...

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To the Basics: Bayesian Inference on A Binomial Proportion

July 4, 2012
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To the Basics: Bayesian Inference on A Binomial Proportion

Think of something observable – countable – that you care about with only one outcome or another. It could be the votes cast in a two-way election in your town, or the free throw shots the center on your favorite...

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Olive vs. Sunflower oil Spectra – 002 (ChemoSpec)

July 1, 2012
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Olive vs. Sunflower oil Spectra – 002 (ChemoSpec)

I add other data set of “sunflower oil” to import together with the olive oil into ChemoSpec R package. Before, as I showed in a video (Preparing spectra to import into ChemoSpec), every sample has been acquired with a NIR instrument (in transmitta...

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Olive Oil NIR/VIS Spectra – 001 (ChemSpec)

June 25, 2012
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Olive Oil NIR/VIS Spectra – 001 (ChemSpec)

I continue with the practicing with ChemSpec, and this time I import seven spectra of olive oil. This time I have been more careful and I have the frequency column as numeric form the CSV file. Once I have the spectra (with and offset):Take in account ...

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useR 2012: main conference braindump

June 24, 2012
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useR 2012: main conference braindump

I knew R was versatile, but DANG, people do a lot with it: > > … I don’t think anyone actually believes that R is designed to make *everyone* happy. For me, R does about 99% of the things I … Continue reading →

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Learning a new language

June 21, 2012
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Learning a new language

It had been a very long time since I’d tried to learn a new programming language. I started C in 1987, S in 1992, and Perl in 1997, but nothing really new in the subsequent 15 years. A friend now has me doing D, wanting to find time to learn ruby, and, most recently, playing

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Confidence intervals with tiers: functions for between-subjects (independent measures) ANOVA

June 21, 2012
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Confidence intervals with tiers: functions for between-subjects (independent measures) ANOVA

In a previous post I showed how to plot difference-adjusted CIs for between-subjects (independent measures) ANOVA designs (see here). The rationale behind this kind of graphical display is introduced in Chapter 3 of Serious stats (and summarized in my earlier blog post). In a between-subjects – or in indeed in a within-subjects (repeated measures) – design

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