ggplot2 0.9.2.1
----------------------------------------------------------------

BUG FIXES

* find_global now searches for objects in the namespace environment
  instead of the package environment. This fixes problems when ggplot2
  is imported to another package but not attached.

ggplot2 0.9.2
----------------------------------------------------------------

THEME SYSTEM

* The theme system has been completely rewritten. (Winston Chang)

* The functions `theme_text`, `theme_line`, and so on have been renamed to
  `element_text`, `element_line`, and so on.

* The `opts()` function has been renamed to `theme()`.

* To set the plot title, use `labs(title = "...")` or `ggtitle("...")
  instead of `opts(title = "...")`.

* Elements are now just lists of properties, instead of functions that
  return grobs.

* Theme elements now can inherit properties. For example, `axis.title.x`
  inherits properties from `axis.title`, which in turn inherits from
  `text`. The inheritance tree is stored in ggplot2::.element_tree.

* Theme objects can now be added to each other with `+`, without a ggplot
  object. There is also a new `%replace%` operator for adding theme
  objects together.

* Vertical and horizontal grid lines can now be controlled independently,
  with `axis.grid.major.x`, `axis.grid.major.y` (and the same for minor);
  `axis.ticks.x` and `axis.ticks.y`; and `axis.line.x` and `axis.line.y`.

* The `size` property of theme elements can be defined relative to the
  parent objects, using the `rel()` function.

MINOR FEATURES

* ggplot2 now uses the external gtable package instead of internal gtable
  functions.

* The condition that set parameters (e.g. `colour = "red"`) could only be of
  length one has been relaxed - they may now be of length one, or exactly the
  same length as the data. Recycling is not done because it makes it harder to
  spot problems. This makes `annotate` considerably more flexible. (Fixes
  #489)

* `stat_contour` is now somewhat faster

* new stat class `stat_ecdf` that shows empirical cumulative distribution
  function. (Kohske Takahashi)

* Dependency on `gpclib` removed, and `fortify.SpatialPolygonsDataFrame` will
  now use `rgeos` if available - this is particularly useful if you're not
  able to use the non-free `gpclib`.

* `ggsave` now supports emf output files.

* all "template" plots (`plotmatrix`, `ggorder` etc) have been deprecated and
  will be removed in a future version. These plots are poorly tested and
  poorly supported and really belong in a separate package.

* The default guide for continuous color/fill scale is now colourbar.
  (Kohske Takahashi. Fixes #555)

* The arrowhead of geom-path and geom-segment with `arrow = TRUE` is
  now filled with the same colour as the path.

* The algorithm for calculating breaks locations has been changed from
  `pretty_breaks()` to `extended_breaks()` from the 'labeling' package
  by Justin Talbot. (Winston Chang. Fixes #580)

* `scale_type`, the function used to pick which type of scale should be
   used for a given type of input variable is now an S3 generic. That
   means that if you want to add a new default type of scale you can
   provide a method - it should return a string giving the name of the
   scale to use (e.g. "continuous", "discrete", "date")

* When there are multiple guides (legends), the order that they are
  displayed can now be controlled manually. (Kohske Takahashi. Fixes
  #470)

* When a scale for a given aesthetic is added to a plot more than once,
  display a message indicating that the first scale will be replaced.
  (Winston Chang. Fixes #518)

DOCUMENTATION

* All geoms and stats now document their aesthetics. (Thanks to joranE.
  Fixes #447)

BUG FIXES

* `scale_x_continuous` now respects `na.value` (Fixes #522)

* `geom_map` now correctly uses set aesthetics (e.g. `colour = "green"`)

* Setting breaks outside the limits of the x or y axis no longer causes
  errors. (Kohske Takahashi. Fixes #552)

* `facet_locate` no longer evaluates unneeded expressions. (Winston
  Chang. Fixes #565)

* `annotation_map` now gets group id from munched data. (Winston Chang.
  Fixes #568)

* `geom_raster` now supports alpha. (Kohske Takahashi. Fixes #596)

* Both axis lines are now drawn above the plotting area panel.
  (Winston Chang. Fixes #585)

* The jitter resolution is now correctly calculated when the data
  does _not_ include zero. (Thanks to Karl Ove Hufthammer. Fixes #572)

* Legend icons for `geom_boxplot` now display linetype. (Kohske
  Takahashi. Fixes #608)

* Facets now appear in the correct order when layers with different
  factor levels are added. (Winston Chang. Fixes #543)

* Distances in polar coordinates are calculated along spiral arcs,
  instead of straight-line distance. (Winston Chang. Fixes #471)

* `fortify.SpatialPolygonsDataFrame` now uses the correct ordering.
  (Charlotte Wickham. Fixes #434)

* `stat_vline` and `stat_hline` no longer throw errors when
  `xintercept` and `yintercept` are passed to them. (Winston Chang.
  Fixes #624)

ggplot2 0.9.1
----------------------------------------------------------------

MINOR FEATURES

* `ggstructure` and `ggorder`, which call `ggpcp`, no longer have a 
  `scale` argument since `ggpcp` does not have one.

* built in datasets have been checked to make sure they use characters,
  factors and ordered factors appropriately

* `geom_raster` and `annotation_raster` gain new `interpolate` argument for
  controlling whether or not rasters are interpolated

* Added `plot` as an alias for `print` for ggplot objects.

* Visual tests have been moved to /visual_test and modified to work with the
  vtest package. (Thanks to Winston Chang)

* `geom_dotplot`: now supports stacking. It uses `stackgroups = TRUE` instead
  of the usual position="stack", for technical reasons. It also will stack in
  the x direction when binning along the y axis. (Thanks to Winston Chang)

* `geom_rug` now allows control over which sides to put the rug lines, with
  the `sides` argument. (Thanks to Winston Chang)

* `annotation_logticks`: a new geom that adds tick marks on the inside of the
  plotting rectangle that have diminishing spacing for log-10 axes. (Thanks
  to Winston Chang)

* Coordinate expansion is now handled by an interaction of the scale and
  coord, rather than by the scale only. Also, the `wise` argument is no
  longer needed. (Thanks to Winston Chang and Kohske Takahashi)

BUG FIXES

* `facet_grid` no longer drops duplicate cases (Fixes #443)

* `munch_range` properly reports the x and y range. (Thanks to Winston Chang)

* `stat_bin2d` handles data with NA in the position variables. Error was
  triggered when scale was limited to a range smaller than the range of
  the data. (Bug reported by Tao Gao; diagnosed and fixed by Brian Diggs)

* `scale_*_identity` will now produce a legend when `guide = "legend"` and no
  breaks or labels are supplied (Fixes #453)

* `geom_map` now works with `coord_map` (Fixes #480)

* discrete scales now accept named vectors of labels again (Fixes #427)

* `geom_raster` works better with categorical input (Fixes #463)

* `qplot` no longer uses non-standard evaluation for geom/stat arguments - it
  doesn't seem to be needed and was causing problems when qplot was used in
  special environments (e.g. in knitr) (Fixes #377)

* `coord_train.polar` and `coord_train.trans` remove NAs from breaks.
  (Thanks to Winston Chang. Fixes #422)

* Theta breaks with `coord_polar` have equal angular spacing. (Thanks to
  Winston Chang and Kohske Takahashi. Fixes #288)

* Empty data frames are now handled correctly: layers with empty data are
  dropped silently, instead of inheriting data from the plot. (Thanks to
  Winston Chang. Fixes #31, #332, #506 and #507)

* The alpha value of set colours is now preserved by default. To return to the
  old behaviour, set `alpha = 1`. (Fixes #475)

* `scale_*_manual` will throw an error if you have too few values. (Fixes
  #512)
  
* `facet_wrap` gets the `as.table` argument back. (Fixes #497)

* `resolution` now returns 1 when range is zero. (Fixes #526)

* Titles are displayed above legend when legend is on top. (Thanks to
  Kohske Takahashi. Fixes #432)

* Specifying breaks outside coord limits works. (Thanks to Kohske Takahashi.
  Fixes #430)

* `renames_aes` now uses exact matching instead of partial matching. (Thanks
  to Winston Chang. Fixes #529)

* `labs()` now works with American spellings. (Thanks to Winston Chang.
  Fixes #521)

* `stat_density2d` sets the limits for `kde2d` from the limits of the x and
  y scales. (Thanks to Winston Chang)

ggplot2 0.9.0
----------------------------------------------------------------

NEW FEATURES

* `annotation_custom`: a new geom intended for use as static annnotations that
  are the same in every panel. Can be used to add inset plots, tables, and
  other grid-based decorations inside the plot area (Contributed by Baptiste
  Auguié).

* `geom_map`: a new special case of `geom_polygon` useful when you are drawing
  maps, particularly choropleth maps. It is matched with `annotation_map`, an
  even faster special case when you want the same map drawn in each panel.

* `geom_raster` is a special case of `geom_tile` for equally sized rectangular
  tiles. It uses the raster functionality of R graphics devices for massively
  increased speed and much decreased file sizes. It is matched with
  `annotation_raster`, an even faster special case, for when you want to draw
  the same raster in each panel.

* `geom_violin`: an implementation of violin plots, which are a way of
  visualizing kernel density estimates. (Thanks to Winston Chang)

* `geom_dotplot`: dot plots, as described in Wilkinson (1999). To bin the
  data, it uses `stat_bindot` to bin the data, which has two methods: histodot
  and dot-density. Histodot binning uses fixed-width bins just like
  `stat_bin`, while dot-density binning uses variable-width bins. A new grob,
  `grob_dotstack` is used to render the dots. (Thanks to Winston Chang)

* New fortify methods have been added for objects produced by the `multcomp`
  package.

* `stat_summary2d` and `stat_summary_hex`. These are work like `stat_bin2d`
  and stat_binhex but allow any summarisation function (instead of just
  count). They are 2d analogs of `stat_summary`

* `facet_grid`: The space argument now supports `free_x` and `free_y` next to
  `free` and `fixed, this allows the user to adjust the spatial scaling of the
  facets in either the x or y direction. This is especially useful when the
  scales are very different. In this case space = `free` could make some
  facets very small. (Thanks to Willem Ligtenberg)

DOCUMENTATION

* Thorough clean up and checking, including documenting all arguments, adding
  systematic cross-references, and adding commonly requested examples. Thanks
  to Jake Russ and Dennis Murphy for the help.

* Complete series of aesthetics pages (grouped subsets of aesthetics) with
  examples of how to use the major ones, see e.g. `?fill`, `?shape`, `?x`,

* Added a complete list of theme opts with usage examples in `?opts`

* Added "translate" pages to demonstrate usage between qplot and ggplot, GPL,
  base and lattice graphics: `?translate_qplot_base`, `?translate_qplot_gpl`,
  `?translate_qplot_lattice`, `?translate_qplot_ggplot`,

SCALES

* Scales have been rewritten to use the new `scales` package, which does a
  much better job at defining what a scale is and making it easier for you to
  create your own scales. Scales should now behave much more consistently, and
  it should be easier for me to add new features in the future.

* `breaks` parameter can now be a function, which will be passed the scale
  limits and expected to return a character vector of breaks

* `labels` parameter can now be a function - this replaces the previous
  formatter function that only some scales possessed, and the `major` argument
  to the data time scales. This function should take a vector of breaks as
  input, and return a character vector or list of expressions as output. See
  `comma_format`, `dollar_format`, `percent_format`, `scientific_format`,
  `parse_format` and `math_format` for examples

* Transformations are now provided by the scales package - see `?trans_new`
  for list of available transformations, and how to create your own. The
  transformations in this package should do a better job at computing default
  breaks.

* Transformations for continuous scales are now detected automatically when
  the default scales are added. This ensures that dates and date times will
  display correctly when used for any aesthetic - previously they only worked
  with position scales. The system is now also easier to extend to new types
  of continuous data that you might want to plot.  (Fixes #48)

* All scales now accept a `na.value` parameter which provides an aesthetic
  value to be used for `NA` values in the data. Colour/fill scales default to
  grey, which should stand out as different from non-missing values.

* The new `oob` (out of bounds) parameter controls how scales deals with
  values outside the limits. The default action is `censor` - see `clip` for
  another option.

* Only `scale_x_log10`, `scale_x_sqrt` and `scale_x_reverse` provided as
  convenience functions for x and y scales. Use e.g. `scale_x_continuous(trans
  = "log")` to access others

* `set_default_scale` has been removed. If you want to change the default
  scale for an aesthetic, just create a function called
  `scale_aesthetic_continuous` or `scale_aesthetic_discrete` that returns the
  scale that you want.  For example:
  
      p <- qplot(mpg, wt, data = mtcars, colour = factor(cyl))
      p
      scale_colour_discrete <- scale_colour_brewer
      p

* Scales now automatically shrink to what is actually displayed on the plot,
  not the underlying data used for statistical transformation. If you want the
  old behaviour, supply `shrink = FALSE` to the facetting specification.
  (Fixes #125)

* `scale_colour_gradient` and `scale_fill_gradient` now use a colour scheme
  with constant hue but varying chroma and luminance. This is better because
  it creates a natural ordering inline with the order of the colour values.

FACETS

* Converted from proto to S3 objects, and class methods (somewhat) documented
  in `facet.r`. This should make it easier to develop new types of facetting
  specifications.

* The new `facet_null` specification is applied in the default case of no
  faceting. This special case is implemented more efficiently and results in
  substantial performance improvements for non-facetted plots.

* Facetting variables will no longer interfere with aesthetic mappings - 
  `facet_wrap(~ colour)` will no longer affect the colour of points.

DEVELOPMENT

* ggplot2 has moved away from the two (!!) homegrown documentation systems
  that it previously relied on, and now uses roxygen extensively. The current
  downside is that this means that ggplot2 website can no longer be updated,
  but I hope work with the `helpr` package will resolve that shortly.

* ggplot2 now uses a `NAMESPACE`, and only exports functions that should be
  user visible - this should make it play considerably more nicely with other
  packages in the R ecosystem. Note that this means you now need to explicitly
  load `plyr` (and other packages) if you are using them elsewhere in your
  code.

* ggplot2 now has a start on a set of automated tests. As this test suite
  expands it will help me ensure that bugs stay fixed, and that old bugs don't
  come back in new versions. A test suite also gives me more confidence when
  I'm modifying code, which should help with general code quality.

COORDS

* Converted from proto to S3 objects, and class methods (somewhat) documented
  in `coord.r`. This should make it easier to develop new types of coordinate
  systems.

* Added a new method `coord_range` for finding the x and y range even after
  coordinates have been transformed to other names (eg., theta and r). (Thanks
  to Winston Chang)

RENDERING 

* When printing a ggplot2 object, the rendered plot information is returned
  invisibly. You can capture this with (e.g.) `x <- print(qplot(mpg, wt, data
  = mtcars))` and in the future will be able to use it to get information
  about the plot computations, such as the range of all the scales, and the
  exact data that is plotted.

* Drawing a plot takes place in three documented steps: `ggplot_build` which
  creates a list of data frames ready for rendering builds, `ggplot_gtable`
  which creates a `gtable` of grobs, and `grid.draw` which renders the grobs
  on screen. Each of these returns a data structure which should be useful for
  understanding and modifying the rendered plot. This is still a work in
  progress, so please ask questions if anything is confusing.

* The `drop` and `keep` parameters to `ggsave` and `print.ggplot` have been
  dropped, as the data structure returned by `ggplot_gtable` is sufficiently
  rich enough to remove the need for them.

* Axis labels are now centred underneath the panels (not the whole plot), and
  stick close to the panels regardless of the aspect ratio.

GUIDES

* Guides (particularly legends) have been rewritten by Kohske Takahashi to
  provide considerably more layout flexibility.

* `guide_legend` now supports multi-row/column legend and reversed order,
  gives more flexible positioning of title and label, and can override
  aesthetics settings. This is useful, for example, when alpha value in a
  panel is very low but you want to show vivid legend.

* `guide_colorbar` is a guide specially for continuous colour scales as
  produced by colour and fill scales.

MINOR CHANGES

* `geom_text` now supports `fontfamily`, `fontface`, and `lineheight`
  aesthetics for finer control over text display. (Thanks to Kohske Takahashi
  for the patch. Fixes #60)

* `collide`, which powers `position_dodge` and `position_stack`, now does not
  error on single x values (Thanks to Brian Diggs for a fix. #157)

* `...` in `ggplot` now passed on to `fortify` method when used with an object
  other than a data frame

* `geom_boxplot`: outlier colour and shape now default to values set by the
  aesthetic mapping (thanks to suggestion by Ben Bolker), the width of the
  median line is now `fatten` times the width of the other lines (thanks to
  suggestion by Di Cook), and the line type can now be set. Notched box
  plots are now supported by setting `notch = TRUE` (thanks to Winston Chang
  for the patch).

* `ggsave` can work with cm and mm `units` (Thanks to patch from Jean-Olivier
  Irisson)

* `scale_shape` finally returns an error when you try and use it with a
  continuous variable

* `stat_contour` no longer errors if all breaks outside z range (fixes #195).

* `geom_text` remove rows with missing values with warning (fixes #191)

* New generic function `autoplot` for the creation of complete plots
  specific to a given data structure. Default implementation throws
  an error. It is designed to have implementations provided by other
  packages.  (Thanks to suggestion by Brian Diggs)
  
* `ggpcp` loses the `scale` argument because it relied on reshape(1) code

* `map_data` passes `...` on to `maps::map` (Fixes #223)

* `coord_fixed` accepts `xlim` and `ylim` parameters to zoom in on x and y
  scales (Fixes #91)

* ggplot2 will occasionally display a useful hint or tip on startup.  Use
  `suppressPackageStartupMessages` to eliminate

* `stat_binhex` uses correct bin width for computing y axis bounds. (Fixes
  #299, thanks to Dave Henderson for bug report and fix.)

* `stat_smooth` now adjusts confidence intervals from `loess` using a 
  t-based approximation

* `stat_smooth` reports what method is used when method is "auto". It also
  picks the method based on the size of the largest group, not individually by
  group. (Thanks to Winston Chang)

* `stat_bin` and `geom_histogram` now use right-open, left-closed intervals by
  default. Use `right = TRUE` to return to previous behaviour. 

* `geom_vline`, `geom_hline`, and `geom_abline` now work with non-Cartesian
  coordinate systems. (Thanks to Winston Chang)
