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Tidy up news and announcement files

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hadley committed Apr 11, 2009
1 parent b30ef29 commit 4b87deafb88f129d59d755f33c50a9c9432036a1
Showing with 21 additions and 36 deletions.
  1. +5 −28 ANNOUNCE
  2. +16 −8 NEWS
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@@ -1,38 +1,15 @@
-plyr is a set of tools that solves a common set of problems: you need to break a big problem down into manageable pieces, operate on each pieces and then put all the pieces back together. This is useful if you want to:
+plyr is a set of tools for a common set of problems: you need to break down a big data structure into manageable pieces, operate on each piece and then put all the pieces back together. For example, you might want to:
* fit the same model to subsets of a data frame
* quickly calculate summary statistics for each group
* perform group-wise transformations like scaling or standardising
* eliminate for-loops in your code
-It's already possible to do this with split and the apply functions, but plyr just makes it all a bit easier with:
+It's already possible to do this with built-in functions (like split and the apply functions), but plyr just makes it all a bit easier with:
- * consistent names, arguments and outputs
+ * absolutely consistent names, arguments and outputs
* input from and output to data.frames, matrices and lists
* progress bars to keep track of long running operations
- * built-in error recovery
- * the choice of passing chunks as rows or as variables
+ * built-in error recovery, and informative error messages
-plyr functions are named according to the type of object they input (first letter) and output (second letter):
-
- * llply = from a list to a list
- * alply = from an array (or vector, or matrix) to a list
- * ldply = from a list to a data.frame
- * d_ply = from a data.frame, ignore output
- * and so on for llply, laply, ldply, l_ply, alply, aaply, adply, a_ply, dlply, daply, dply, d_ply
-
-plyr also provides:
-
- * m*ply which works in a similar way to mapply
- * r*ply which works in a similar way to replicate
-
-plyr also has a number of helper functions that operate on functions, returning functions
-
- * colwise to turn functions that operate on a single vector of numbers into functions that operate on columns
- * each to return a named vector containing the results of multiple functions
-
-You can find out more at http://had.co.nz/plyr/, including a 20 page introductory guide, http://had.co.nz/plyr/plyr-intro.pdf.
-
-Regards,
-
-Hadley
+You can find out more at http://had.co.nz/plyr/, including a 20 page introductory guide, http://had.co.nz/plyr/plyr-intro.pdf. You can ask questions about plyr (and data-manipulation in general) on the plyr mailing list. Sign up at http://groups.google.com/group/manipulatr
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24 NEWS
@@ -1,15 +1,23 @@
plyr 0.1.6 (2008-XX-XX) ---------------------------------------------------
-* use list names where present
-* failwith now accepts a function name, as well as a function itself
-* each now accepts function names, as well as a functions
-* fix typo that was causing a 50% speed penalty for d*ply
-* aaply now works with vectors
-* fix bug in daply which prevented it from working correctly when data frame was split by multiple variables
+Improvements:
+
* all ply functions deal more elegantly when given function names: can supply a vector of function names, and name is used as label in output
+* failwith and each now work with function names as well as functions (i.e. "nrow" instead of nrow)
+* l*ply will use list names where present
+* error messages now give you information about where the error actual occred in your data structure - hopefully this will make problems easier to track down
+
+Speed-ups
+
+* massive speed ups for splitting large arrays
+* fixed typo that was causing a 50% speed penalty for d*ply
+
+Bug fixes:
+
+* daply: now works when the data frame is split by multiple variables
+* aaply: now works with vectors
* ddply: first variable now varies slowest as you'd expect
-* massive speed ups for splitting large arrays, in a similar way to data frames
-* first attempt at informative error messages
+
plyr 0.1.5 (2008-02-23) ---------------------------------------------------

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