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B_03_histogram package:lattice R Documentation
_H_i_s_t_o_g_r_a_m_s _a_n_d _K_e_r_n_e_l _D_e_n_s_i_t_y _P_l_o_t_s
_D_e_s_c_r_i_p_t_i_o_n:
Draw Histograms and Kernel Density Plots, possibly conditioned on
other variables.
_U_s_a_g_e:
histogram(x, data, ...)
densityplot(x, data, ...)
## S3 method for class 'formula':
histogram(x,
data,
allow.multiple, outer = TRUE,
auto.key = FALSE,
aspect = "fill",
panel = lattice.getOption("panel.histogram"),
prepanel, scales, strip, groups,
xlab, xlim, ylab, ylim,
type = c("percent", "count", "density"),
nint = if (is.factor(x)) nlevels(x)
else round(log2(length(x)) + 1),
endpoints = extend.limits(range(as.numeric(x), finite = TRUE), prop = 0.04),
breaks,
equal.widths = TRUE,
drop.unused.levels = lattice.getOption("drop.unused.levels"),
...,
lattice.options = NULL,
default.scales = list(),
subscripts,
subset)
## S3 method for class 'numeric':
histogram(x, data = NULL, xlab, ...)
## S3 method for class 'factor':
histogram(x, data = NULL, xlab, ...)
## S3 method for class 'formula':
densityplot(x,
data,
allow.multiple = is.null(groups) || outer,
outer = !is.null(groups),
auto.key = FALSE,
aspect = "fill",
panel = lattice.getOption("panel.densityplot"),
prepanel, scales, strip, groups, weights,
xlab, xlim, ylab, ylim,
bw, adjust, kernel, window, width, give.Rkern,
n = 50, from, to, cut, na.rm,
drop.unused.levels = lattice.getOption("drop.unused.levels"),
...,
lattice.options = NULL,
default.scales = list(),
subscripts,
subset)
## S3 method for class 'numeric':
densityplot(x, data = NULL, xlab, ...)
do.breaks(endpoints, nint)
_A_r_g_u_m_e_n_t_s:
x: The object on which method dispatch is carried out.
For the 'formula' method, a formula of the form '~ x | g1 *
g2 * ...' indicates that histograms or Kernel Density
estimates of 'x' should be produced conditioned on the levels
of the (optional) variables 'g1, g2, ...'. 'x' can be
numeric (or factor for 'histogram'), and each of 'g1, g2,
...' must be either factors or shingles.
As a special case, the right hand side of the formula can
contain more than one variable separated by a '+' sign. What
happens in this case is described in details in the
documentation for 'xyplot'. Note that in either form, all
the variables involved in the formula have to have same
length.
For the 'numeric' and 'factor' methods, 'x' replaces the 'x'
vector described above. Conditioning is not allowed in these
cases.
data: For the 'formula' method, an optional data frame in which
variables are to be evaluated. Ignored with a warning in
other cases.
type: Character string indicating type of histogram to be drawn.
'"percent"' and '"count"' give relative frequency and
frequency histograms, and can be misleading when breakpoints
are not equally spaced. '"density"' produces a density scale
histogram.
'type' defaults to '"percent"', except when the breakpoints
are unequally spaced or 'breaks = NULL', when it defaults to
'"density"'.
nint: Number of bins. Applies only when 'breaks' is unspecified or
'NULL' in the call. Not applicable when the variable being
plotted is a factor.
endpoints: vector of length 2 indicating the range of x-values that is
to be covered by the histogram. This applies only when
'breaks' is unspecified and the variable being plotted is not
a factor. In 'do.breaks', this specifies the interval that
is to be divided up.
breaks: usually a numeric vector of length (number of bins + 1)
defining the breakpoints of the bins. Note that when
breakpoints are not equally spaced, the only value of 'type'
that makes sense is density. When unspecified, the default
is to use
breaks = seq_len(1 + nlevels(x)) - 0.5
when 'x' is a factor, and
breaks = do.breaks(endpoints, nint)
otherwise. Breakpoints calculated in such a manner are used
in all panels.
Other values of 'breaks' are possible, in which case they
affect the display in each panel differently. A special
value of 'breaks' is 'NULL', in which case the number of bins
is determined by 'nint' and then breakpoints are chosen
according to the value of 'equal.widths'. Other valid values
of 'breaks' are those of the 'breaks' argument in 'hist'.
This allows specification of 'breaks' as an integer giving
the number of bins (similar to 'nint'), as a character string
denoting a method, and as a function.
equal.widths: logical, relevant only when 'breaks=NULL'. If 'TRUE',
equally spaced bins will be selected, otherwise,
approximately equal area bins will be selected (this would
mean that the breakpoints will *not* be equally spaced).
n: number of points at which density is to be evaluated
panel: The function that uses the packet (subset of display
variables) corresponding to a panel to create a display.
Default panel functions are documented separately, and often
have arguments that can be used to customize its display in
various ways. Such arguments can usually be directly
supplied to the high level function.
allow.multiple, outer, auto.key, aspect, prepanel, scales,: strip,
groups, xlab, xlim, ylab, ylim, drop.unused.levels,:
lattice.options, default.scales, subscripts, subset: See
'xyplot'
weights: numeric vector of weights for the density calculations,
evaluated in the non-standard manner used for 'groups' and
terms in the formula, if any. If this is specified, it is
subsetted using 'subscripts' inside the panel function to
match it to the corresponding 'x' values.
At the time of writing, 'weights' do not work in conjunction
with an extended formula specification (this is not too hard
to fix, so just bug the maintainer if you need this feature).
bw, adjust, kernel, window, width, give.Rkern, from, to, cut,: na.rm:
arguments to 'density', passed on as appropriate
...: Further arguments. See corresponding entry in 'xyplot' for
non-trivial details.
_D_e_t_a_i_l_s:
'histogram' draws Conditional Histograms, while 'densityplot'
draws Conditional Kernel Density Plots. The density estimate in
'densityplot' is actually calculated using the function 'density',
and all arguments accepted by it can be passed (as '...') in the
call to 'densityplot' to control the output. See documentation of
'density' for details. (Note: The default value of the argument
'n' of 'density' is changed to 50.)
These and all other high level Trellis functions have several
arguments in common. These are extensively documented only in the
help page for 'xyplot', which should be consulted to learn more
detailed usage.
'do.breaks' is an utility function that calculates breakpoints
given an interval and the number of pieces to break it into.
_V_a_l_u_e:
An object of class '"trellis"'. The 'update' method can be used to
update components of the object and the 'print' method (usually
called by default) will plot it on an appropriate plotting device.
_N_o_t_e:
The form of the arguments accepted by the default panel function
'panel.histogram' is different from that in S-PLUS. Whereas S-PLUS
calculates the heights inside 'histogram' and passes only the
breakpoints and the heights to the panel function, here the
original variable 'x' is passed along with the breakpoints. This
allows plots as in the second example below.
_A_u_t_h_o_r(_s):
Deepayan Sarkar
_R_e_f_e_r_e_n_c_e_s:
Sarkar, Deepayan (2008) "Lattice: Multivariate Data Visualization
with R", Springer.
_S_e_e _A_l_s_o:
'xyplot', 'panel.histogram', 'density', 'panel.densityplot',
'panel.mathdensity', 'Lattice'
_E_x_a_m_p_l_e_s:
require(stats)
histogram( ~ height | voice.part, data = singer, nint = 17,
endpoints = c(59.5, 76.5), layout = c(2,4), aspect = 1,
xlab = "Height (inches)")
histogram( ~ height | voice.part, data = singer,
xlab = "Height (inches)", type = "density",
panel = function(x, ...) {
panel.histogram(x, ...)
panel.mathdensity(dmath = dnorm, col = "black",
args = list(mean=mean(x),sd=sd(x)))
} )
densityplot( ~ height | voice.part, data = singer, layout = c(2, 4),
xlab = "Height (inches)", bw = 5)