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psmat

Matrix / Array from Panel Series

Description

psmat efficiently expands a panel-vector or plm::pseries into a matrix. If a data frame or plm::pdata.frame is passed, psmat returns (default) a 3D array or a list of matrices.

Usage

psmat(x, ...)

## Default S3 method:
psmat(x, g, t = NULL, transpose = FALSE, ...)

## S3 method for class 'pseries'
psmat(x, transpose = FALSE, ...)

## S3 method for class 'data.frame'
psmat(x, by, t = NULL, cols = NULL, transpose = FALSE, array = TRUE, ...)

## S3 method for class 'pdata.frame'
psmat(x, cols = NULL, transpose = FALSE, array = TRUE, ...)


## S3 method for class 'psmat'
plot(x, legend = FALSE, colours = legend, labs = NULL, ...)

Arguments

`x`	a vector, panel series (`plm::pseries`), data frame or panel data frame (`plm::pdata.frame`).
`g`	a factor, `GRP` object, atomic vector (internally converted to factor) or a list of vectors / factors (internally converted to a `GRP` object) used to group `x`. If the panel is balanced an integer indicating the number of groups can also be supplied. See Examples.
`by`	data.frame method: Same input as `g`, but also allows one- or two-sided formulas using the variables in `x`, i.e. `~ idvar` or `var1 + var2 ~ idvar1 + idvar2`.
`t`	same inputs as `g`, to indicate the time-variable(s) or second identifier(s). `g` and `t` together should fully identify the panel. If `t = NULL`, the data is assumed sorted and `seq_col` is used to generate rownames for the output matrix.
`cols`	data.frame method: Select columns using a function, column names, indices or a logical vector. Note: `cols` is ignored if a two-sided formula is passed to `by`.
`transpose`	logical. `TRUE` generates the matrix such that `g/by -> columns, t -> rows`. Default is `g/by -> rows, t -> columns`.
`array`	data.frame / pdata.frame methods: logical. `TRUE` returns a 3D array (if just one column is selected a matrix is returned). `FALSE` returns a list of matrices.
`...`	arguments to be passed to or from other methods, or for the plot method additional arguments passed to `ts.plot`.
`legend`	logical. Automatically create a legend of panel-groups.
`colours`	logical. Automatically colour by panel-groups.
`labs`	character. Provide a character-vector of variable labels / series titles when plotting an array.

Details

For plm::pseries, the first index variable is taken to be the group-id and the second the time variable. If more than 2 index variables are attached to plm::pseries, the last one is taken as the time variable and the others are taken as group-id's and interacted.

Value

A matrix or 3D array containing the data in x, where by default the rows constitute the groups-ids (g/by) and the columns the time variable or individual ids (t). 3D arrays contain the variables in the 3rd dimension. The objects have a class 'psmat', and also a 'transpose' attribute indicating whether transpose = TRUE.

Note

The pdata.frame method only works for properly subsetted objects of class 'pdata.frame'. A list of 'pseries' won't work. There also exist simple aperm and [ (subset) methods for 'psmat' objects. These differ from the default methods only by keeping the class and the 'transpose' attribute.

Examples

## World Development Panel Data
head(wlddev)                                                    # View data
qsu(wlddev, pid = ~ iso3c, cols = 9:12, vlabels = TRUE)         # Sumarizing data
str(psmat(wlddev$PCGDP, wlddev$iso3c, wlddev$year))             # Generating matrix of GDP
r <- psmat(wlddev, PCGDP ~ iso3c, ~ year)                       # Same thing using data.frame method
plot(r, main = vlabels(wlddev)[9], xlab = "Year")               # Plot the matrix
str(r)                                                          # See srructure
str(psmat(wlddev$PCGDP, wlddev$iso3c))                          # The Data is sorted, could omit t
str(psmat(wlddev$PCGDP, 216))                                   # This panel is also balanced, so
# ..indicating the number of groups would be sufficient to obtain a matrix

ar <- psmat(wlddev, ~ iso3c, ~ year, 9:12)                      # Get array of transposed matrices
str(ar)
plot(ar)
plot(ar, legend = TRUE)
plot(psmat(collap(wlddev, ~region+year, cols = 9:12),           # More legible and fancy plot
           ~region, ~year), legend = TRUE,
     labs = vlabels(wlddev)[9:12])

psml <- psmat(wlddev, ~ iso3c, ~ year, 9:12, array = FALSE)     # This gives list of ps-matrices
head(unlist2d(psml, "Variable", "Country", id.factor = TRUE),2) # Using unlist2d, can generate DF
 
## Using plm simplifies things
pwlddev <- plm::pdata.frame(wlddev, index = c("iso3c","year"))  # Creating a Panel Data Frame
PCGDP <- pwlddev$PCGDP                                          # A panel-Series of GDP per Capita
head(psmat(PCGDP), 2)                                           # Same as above, more parsimonious
plot(psmat(PCGDP))
plot(psmat(pwlddev[9:12]))
plot(psmat(G(pwlddev[9:12])))                                   # Here plotting panel- growth rates

collapse

Advanced and Fast Data Transformation

v1.5.3

GPL (>= 2) | file LICENSE

Authors

Sebastian Krantz [aut, cre], Matt Dowle [ctb], Arun Srinivasan [ctb], Laurent Berge [ctb], Dirk Eddelbuettel [ctb], Josh Pasek [ctb], Kevin Tappe [ctb], R Core Team and contributors worldwide [ctb], Martyn Plummer [cph], 1999-2016 The R Core Team [cph]

Initial release

2021-03-05