Posts Tagged ‘ R ’

Le Monde puzzle [#1003]

April 17, 2017
By
Le Monde puzzle [#1003]

A purely arithmetic Le Monde mathematical puzzle: Find the four integers w, x, y, z such that the four smallest pairwise sums among the six pairwise sums are 59, 65, 66, and 69. Similarly, find the four smallest of the five integers v, x, y, z such that the five smallest pairwise sums among the […]

Read more »

Encoding categorical variables: one-hot and beyond

April 15, 2017
By
Encoding categorical variables: one-hot and beyond

(or: how to correctly use xgboost from R) R has "one-hot" encoding hidden in most of its modeling paths. Asking an R user where one-hot encoding is used is like asking a fish where there is water; they can’t point to it as it is everywhere. For example we can see evidence of one-hot encoding … Continue reading Encoding categorical variables: one-hot and beyond

Read more »

optimultiplication [a riddle]

April 13, 2017
By
optimultiplication [a riddle]

The riddle of this week is about an optimisation of positioning the four digits of a multiplication of two numbers with two digits each and is open to a coding resolution: Four digits are drawn without replacement from {0,1,…,9}, one at a time. What is the optimal strategy to position those four digits, two digits […]

Read more »

optimultiplication [a riddle]

April 13, 2017
By
optimultiplication [a riddle]

The riddle of this week is about an optimisation of positioning the four digits of a multiplication of two numbers with two digits each and is open to a coding resolution: Four digits are drawn without replacement from {0,1,…,9}, one at a time. What is the optimal strategy to position those four digits, two digits […]

Read more »

optimultiplication [a riddle]

April 13, 2017
By
optimultiplication [a riddle]

The riddle of this week is about an optimisation of positioning the four digits of a multiplication of two numbers with two digits each and is open to a coding resolution: Four digits are drawn without replacement from {0,1,…,9}, one at a time. What is the optimal strategy to position those four digits, two digits […]

Read more »

pandas “transform” using the tidyverse

April 12, 2017
By
pandas “transform” using the tidyverse

Chris Moffit has a nice blog on how to use the transform function in pandas. He provides some (fake) data on sales and asks the question of what fraction of each order is from each SKU. Being a R nut and a tidyverse fan, I thought to compare and contrast the code for the pandas […]

Read more »

pandas “transform” using the tidyverse

April 12, 2017
By
pandas “transform” using the tidyverse

Chris Moffit has a nice blog on how to use the transform function in pandas. He provides some (fake) data on sales and asks the question of what fraction of each order is from each SKU. Being a R nut and a tidyverse fan, I thought to compare and contrast the code for the pandas […]

Read more »

Teaching pivot / un-pivot

April 11, 2017
By
Teaching pivot / un-pivot

Authors: John Mount and Nina Zumel Introduction In teaching thinking in terms of coordinatized data we find the hardest operations to teach are joins and pivot. One thing we commented on is that moving data values into columns, or into a “thin” or entity/attribute/value form (often called “un-pivoting”, “stacking”, “melting” or “gathering“) is easy to … Continue reading Teaching pivot / un-pivot

Read more »

Statlearn17, Lyon

April 6, 2017
By
Statlearn17, Lyon

Today and tomorrow, I am attending the Statlearn17 conference in Lyon, France. Which is a workshop with one-hour talks on statistics and machine learning. And which makes for the second workshop on machine learning in two weeks! Yesterday there were two tutorials in R, but I only took the train to Lyon this morning: it […]

Read more »

Software for honours students

April 4, 2017
By
Software for honours students

I spoke to our new crop of honours students this morning. Here are my slides, example files and links.   Managing References Mendeley Zotero Paperpile Data analysis and computation Download R Download Rstudio Online R tutorial R packages for time series R packages for econometrics R packages for finance Writing your thesis LaTeX Windows: Download MikTeX […]

Read more »


Subscribe

Email:

  Subscribe