NEWS

## Version 0.2.23

- `DropNA` should now be compatible with `tbl_df` data frames.

- Introduced (a largely internal function) `pull` for extracting single columns
from data frames (including `tbl_df`) and returning them as vectors.
The function is based on Tommy O'Dell's:
<http://stackoverflow.com/a/24730843/1705044>.

## Version 0.2.22

- Fixed a bug in `CasesTable` where multiple variables would cause an error.

- Minor example update and internal code formatting improvements to
`TimeFill`.

## Version 0.2.21

- `CasesTable` function added to report cases after listwise deletion of
missing values for time-series cross-sectional data.

- Fixed a bug where `CountSpell` would fail if all `SpellVar` values were
the same.

- Improved documentation.

## Version 0.2.20

- Internal changes to enable compatability with dplyr version 0.4.4.

- The `Var` argument in `dMerge` is deprecated. Use `by` instead to match
`merge` syntax more closely.

- `DropNA` drops all NAs from the supplied data frame if `Var` is missing.

## Version 0.2.19

- Fixed a bug in `dMerge` that overwrote users `suffixes` specification.
Thanks to @hplieninger for spotting this.

- `FillIn` intelligently fails if `Var1` and `Var2` do not exist in their
respective data.frames.

## Version 0.2.18

- `SpreadDummy` now starts by coercing the `data` to a data frame, so that it
works more smoothly with dplyr data tables.

## Version 0.2.17

- `change` calculate the changes (absolute, percent, and proportion) changes
from a specified lag, including within groups. Replaced `PercChange` which
has the same syntax, but did not find absolute changes.

## Version 0.2.16

- `FindDups` code and documentation improvements.

## Version 0.2.15

- `FindDups` for finding duplicated values in a data frame and subsetting it
to either include or not include them.

## Version 0.2.14

- `grepl.sub` now uses dot notation to pass arguments to `grepl`.

## Version 0.2.13

- Improved error handling and documentation in `CountSpell`.

## Version 0.2.12

Improved error handling in `FillDown` for missing variables.

## Version 0.2.11

Allow arguments for `slide` to be passed throught `StartEnd`.

## Version 0.2.10

`slide` convert with tbl_df.

## Version 0.2.9

Fixed a bug in `slide` when using factor class variables as `GroupVar`.

## Version 0.2.8.3

Minor change to `PercChange` allowing arguments to be passed to `slide`.

Minor internal code improvements.

## Version 0.2.8.2

`FillDown` down accepts just vectors. This is useful when used with dplyr's
`group_by` and `mutate`/`summarize` functions.

## Version 0.2.8.1

Added `TimeVar` argument to `slide`. The argument is optional. When the
argument is specified, then the data is ordered by `Var`-`TimeVar` before
sliding.

- Internal code improvements.

## Version 0.2.8

Added function `TimeExpand`. This expands a data set so that it includes an
observation for each time point in a sequence. Works with grouped data.

## Version 0.2.7.2

- Error message added to `slide` when using grouped data.

## Version 0.2.7.1

Added dplyr version depedency >= 0.3.

Minor `FillIn` change checking for `missing` rather than `NULL` for `Var2`.

## Version 0.2.7

Fixed a bug in `slide` when there are invalid sliding values.

## Version 0.2.6

- Fixed a misspelling in the `CountSpell` documentation. Thanks to
Sascha Schuster.

## Version 0.2.5

- Minor error handling improvements to `grepl.sub`.

## Version 0.2.4

- Added `FillDown` a function that fills in missing (NA) values with the
previous non-missing value.

- Internal code formating improvements.

## Version 0.2.3

- `keepInvalid` argument added to `slide`. This allows the user to specify
whether or not to keep observations for groups for which no valid lag/lead can
be created due to an insufficient number of time points. If TRUE then these
groups are returned to the bottom of the data frame and NA is given for their
new lag/lead variable value.

## Version 0.2.2

Minor internal improvement where slide (and associated functions) return only
data frame class objects

## Version 0.2.1

Minor documentation improvements to `slideMA`.

Internal improvements to `MoveFront`.

## Version 0.2

Added `CountSpell`, a function that returns a variable counting the spell number
for an observation. Works with grouped data.

Added an `OnlyStart` argument to `StartStop` to return only a new `Spell_Start`
variable.

Documentation and internal code improvements.

## Version 0.1.27

`FillIn` internal code improvements.

## Version 0.1.26

!!! `grepl.sub` argument `patterns` changed to `pattern`. !!!

`InsertRow` function allows user to insert a row into a data frame.
Largely implements: http://stackoverflow.com/a/11562428.

Minor documentation improvements.

Minor internal code cleaning.

## Version 0.1.25

No longer depends on the forecast package.

## Version 0.1.24

`slide` and `slideMA` now rely on `dplyr` rather than `plyr` for speed
improvements.

## Version 0.1.23

Minor `StartEnd` bug fix.

## Version 0.1.22

`StartEnd` function added. Finds the starting and ending time points of a spell.

Small improvement to `slide` to drop temporary 'fake' variable' before returning the data frame.

## Version 0.1.21

Small improvement to `FillIn` so that it doesn't attempt to find correlations if Var2 is not numeric.

Error message improvements.

## Version 0.1.20

Added `SpreadDummy` to spread a dummy variable (1's and 0') over a specified time period and for specified groups.

Improved error handling in `slide` for when the number of rows in a group is smaller than the argument set with `slideBy`.

Minor argument default changes in `FindReplace`.

## Version 0.1.19

Added `slideMA` for creating a moving average for a period before or after each time point for a given variable.

Message improvements to `shift`

## Version 0.1.18

Added `NaVar` for creating new variable(s) indicating if there are missing values in other variable(s).

Minor internal improvements to `rmExcept`.

## Version 0.1.17

Added `TimeFill` for creating a continuous Unit-Time-Dummy data frame from a
data frame with Unit-Start-End times.

## Version 0.1.16

Added `message` option to `DropNA`. Allows the user to turn of the drop message.

## Version 0.1.15

Added `VarDrop` for dropping one or more variables from a data frame.

Added `dMerge` which merges 2 data frames and reports/drops/keeps only
duplicates.

## Version 0.1.14

Improve messages for `slide`.

## Version 0.1.13

Added `exact`, `ignore.case`, and `fixed` arguments to `MoveFront` for more flexible variable name matching. Thanks to Felix Haas for the suggestion.

Minor documentation improvements.

## Version 0.1.12

Added `PercChange` for calculating the percentage change from a specified lag, including within groups.

## Version 0.1.11

Added `exact` argument to `FindReplace` to only replace exact pattern matches. Also added argument `vector` to return a vector of the replacement variable
rather than the whole data frame.

Improved warnings for `FindReplace`.

## Version 0.1.10

Added `FindReplace` function to replace multiple patterns found in a character string column of a data frame

## Version 0.1.9

Minor documentation improvements.

## Version 0.1.8

Added `grepl.sub` function to subset a data frame if a specified pattern is
found in a character string.

## Version 0.1.7

Added the utility `rmExcept` for removing all objects from a workspace except
for those specified by the user.

## Version 0.1.6

Speed improvements made to `slide`. Thanks to briatte.

## Version 0.1.5.2

`FillIn` now allows you to drop variables from `D2` in the resulting data set.

## Version 0.1.5.1

`MoveFront` can now move more than one variable to the front of a data frame.

Minor bug fixes in `FillIn`.

Bug fix for `slide` argument `NewVar`.

Documentation improvements.

## Version 0.1.5

Added `slide` and `shift` functions for lagging and leading variables. `shift`
is largely based on TszKin Julian's `shift` function:
<http://ctszkin.com/2012/03/11/generating-a-laglead-variables/>.

## Version 0.1.3

Added `DropNA` to drop observations in a data frame with missing values for
given variables.

## Version 0.1.2

Stop message for `MoveFront` when variable does not exists. Other minor
documentation changes.

## Version 0.1.1

Minor update to `FillIn` for data.frame 1.8.8.

## Version 0.1

First version including the `FillIn` and `MoveFront` commands.