August, 2019 | R-bloggers

How to generate meaningful fake data for learning, experimentation and teaching

August 9, 2019 | AbdulMajedRaja RS

The Problem There’s one thing about R that a lot of people have as their Top-of-Mind. That’s the black-and-white plot of iris dataset which is definitely a huge boring view of R. That’s boring because of aesthetics but also because it’s such a cliched example used ...

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A weighty matter

August 8, 2019 | R on OSM

When we were testing random correlations and weighthings in our last post on diversification, we discovered that randomizing correlations often increased portfolio risk. Then, when we randomized stock weightings on top of our random correlations, we...

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A weighty matter

August 8, 2019 | R on OSM

When we were testing random correlations and weighthings in our last post on diversification, we discovered that randomizing correlations often increased portfolio risk. Then, when we randomized stock weightings on top of our random correlations, we began to see more cases in which one would have better off not being ...

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Correlation is not transitive, in general at least

August 8, 2019 | R-bloggers on Mikkel Meyer Andersen

Update Aug 10, 2019: I wrote a new blog post about the same as below but using a simulation approach. Update Aug 27, 2019: Minor change in how equations are solved (from version 0.9.0.9122). Let \(\rho_{XY}\) be the correlation between the stochastic variables \(X\) and \(Y\) and similarly for \(\rho_{XZ}\) and \(\rho_{YZ}\). ...

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Automatic ‘testthat’ test skeletons with new R package ‘roxytest’ extending ‘roxygen2’

August 8, 2019 | R-bloggers on Mikkel Meyer Andersen

It is important to test software. One approach is unit-testing, and for R packages this can e.g. be done using testthat. It is also important to document software. For R packages roxygen2 is really helpful: It enables you to write documentation in the code file in the R/ folder ... [Read more...]

A New Website

August 8, 2019 | Noam Ross

For me, the task of building a personal website is fraught with so many of my technical, aesthetic, and personal hangups that I hadn’t updated mine since mid-graduate school. Thanks to consistent pestering by Maëlle, though, I finally got around to re-building this one using a modern toolkit. ... [Read more...]

How to Do Mediation Scientifically

August 8, 2019 | Rstats on pi: predict/infer

Mediation analysis has been around a long time, though its popularity has varied between disciplines and over the years. While some fields have been attracted to the potential of mediation models to identify pathways, or mechanisms, through which an independent variable affects an outcome, others have been skeptical that the ... [Read more...]

Speeding up Bayesian sampling with map_rect

August 8, 2019 | Brian Callander

Speeding up Bayesian sampling with map_rect Posted on 9 August, 2019 by Brian Tags: stan, map_rect, within-chain parallelisation, threading, ordinal regression Category: map_rect Fitting a full Bayesian model can be slow, especially with a large dataset. For example, it’d be great to analyse the climate crisis questions in ... [Read more...]

Reversi in R – Part 2: Graphics and Custom Boards

August 8, 2019 | Jack Davis

In this post, I finish the Reversi / Othello game in R by improving the graphics, adding the ability to save and load boards, and fixing bugs. Also, many more boards have been added and tested, including those with unusual shapes, three or more players, and walls that can make the ...

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Confusion matrices – evaluating your classification models

August 8, 2019 | Gary Hutson

As part of my companies commitment to allow our users access to some of our code – we have created a visual way you can assess your accuracy in a confusion matrix. The below was posted on our blog site and shows how to interpret a confusion matrix. I hope the ... [Read more...]

Shapiro-Wilk Test for Normality in R

August 7, 2019 | data technik

I think the Shapiro-Wilk test is a great way to see if a variable is normally distributed. This is an important assumption in creating any sort of model and also evaluating models. Let’s look at how to do this in R! And here is the output: So how do ...

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A Comprehensive Introduction to Working with Databases using R

August 7, 2019 | Rsquared Academy Blog - Explore Discover Learn

Introduction In a previous post, we had briefly looked at connecting to databases from R and using dplyr for querying data. In this new expanded post, we will focus on the following: connect to & explore database read & write data use RStudio SQL script & knitr SQL engine query data using dplyr ...

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In search of the perfect partial plot

August 7, 2019 | Artful Analytics

Introduction Partial dependence (PD) plots are essential for interpreting Random Forests models. For example, in the case of binary classification, PD plots show the marginal effect of individual predictor variables on the probability of the response. Several packages in R will generate PD plots for Random Forests, but I’ve ...

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A Flurry of Facets

August 7, 2019 | Data Imaginist

When I announced the last release of ggforce I hinted that I would like to transition to a more piecemeal release habit and avoid those monster releases that the last one was. True to my word, I am now thrilled to announce that a new version of ggforce is available ...

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A Comprehensive Introduction to Working with Databases using R

August 7, 2019 | Rsquared Academy Blog

Introduction In a previous post, we had briefly looked at connecting to databases from R and using dplyr for querying data. In this new expanded post, we will focus on the following: connect to & explore database read & write data use RStudio SQL script & knitr SQL engine query data using dplyr ...

[Read more...]

B3 is NOT shutting down its ftp site, for now..

August 7, 2019 | R on msperlin

Surprise, surprise. B3’s ftp site is still up and running. Following previous post regarding the shutdown of B3’s ftp site and its impact over GetHFData, I’m happy to report that the site is up and running. We can check it with code:

library(GetHFData)
library(tidyverse)

df.ftp <- ghfd_get_ftp_contents(type.market = 'equity')

## 
## Reading ftp contents for equity(trades) (attempt = 1|10)

# check time difference
max(df.ftp$dates) - min(df.ftp$dates)

## Time difference of 158 days

Let’... [Read more...]

tikzDevice v0.12.3

August 7, 2019 | R on Ralf Stubner

Yesterday tikzDevice version 0.12.3 made it unto CRAN and is now propagating to the mirrors. The tikzDevice package provides a graphics output device for R that records plots in a LaTeX-friendly format. The device transforms plotting commands issued by R functions into LaTeX code blocks. When included in a paper typeset ... [Read more...]

Community Call – Reproducible Workflows at Scale with drake

August 7, 2019 | rOpenSci - open tools for open science

Ambitious workflows in R, such as machine learning analyses, can be difficult to manage. A single round of computation can take several hours to complete, and routine updates to the code and data tend to invalidate hard-earned resul...

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Data Warehousing and Data Mining

August 7, 2019 | Jonathan

The relationship between data mining tools and data warehousing systems can be most easily seen in the connector options of popular analytics software packages. For example, the image below right shows the many source options from which to pull data in from warehouse backends in Tableau Desktop. Microsoft Power BI ...

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Getting Started with Data Science

August 7, 2019 | Pranjali Galgali

A data scientist is someone who uses computer programming, statistics, and mathematics to derive meaningful insights from large quantities of data. For example, a data scientist might conduct a cluster analysis of customer characteristics to inform a marketing campaign or build a machine learning model to diagnose cancer.

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R-bloggers

R news and tutorials contributed by hundreds of R bloggers

August 2019

How to generate meaningful fake data for learning, experimentation and teaching

A weighty matter

A weighty matter

Correlation is not transitive, in general at least

Automatic ‘testthat’ test skeletons with new R package ‘roxytest’ extending ‘roxygen2’

A New Website

How to Do Mediation Scientifically

Speeding up Bayesian sampling with map_rect

Reversi in R – Part 2: Graphics and Custom Boards

Confusion matrices – evaluating your classification models

Shapiro-Wilk Test for Normality in R

A Comprehensive Introduction to Working with Databases using R

In search of the perfect partial plot

A Flurry of Facets

A Comprehensive Introduction to Working with Databases using R

B3 is NOT shutting down its ftp site, for now..

tikzDevice v0.12.3

Community Call – Reproducible Workflows at Scale with drake

Data Warehousing and Data Mining

Getting Started with Data Science

August 2019

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