hadley

hadley has asked 13 questions and find answers to 426 problems.

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I'm chief scientist at RStudio.

hadley questions

Working with rich objects in data.table columns
Combined aggregated and non-aggregate query in SQL
ActiveRecord::StatementInvalid: Could not find table 'tablename'
Efficiently locate group-wise constant columns in a data.frame
Determine if a transaction is active (Postgres)
Blinding a latex paper
Automatically escape unicode characters
Which packages make good use of S4 objects?
Preventing performance regressions in R
Perform a semi-join with data.table

hadley answers

How to get the difference in value between subsequent observations (country-years)?
generate variable names (something like get())
how do tell if its better to standardize your data matrix first when you do principal component analysis in R?
plyr summarize only calls global functions
R: ggplot2, how to add a number of layers to a plot at once to reduce code
Ranking elements within a data.frame
Create and Call Linear Models from List
How to change fill / shade of ggplot2 plot to use/look like Semiotic [duplicate]
ggplot: Pallete Greyscale On Print, Colourful on Screen [duplicate]
Change how R stacks Transparency