gnuplot documentation

32 HISTOGRAMS gnuplot 4.3 45
The fsteps style is only relevant to 2D plotting. It
connects consecutive points with two line segments:
the first from (x1,y1) to (x1,y2) and the second from
(x1,y2) to (x2,y2). The input column requires are
the same as for plot styles lines and points. The
difference between fsteps and steps is that fsteps
traces first the change in y and then the change in
x. steps traces first the change in x and then the
change in y.
See also
steps demo.
with fsteps
31 Histeps
The histeps style is only relevant to 2D plotting.
It is intended for plotting histograms. Y-values
are assumed to be centered at the x-values; the
point at x1 is represented as a horizontal line from
((x0+x1)/2,y1) to ((x1+x2)/2,y1). The lines representing
the end points are extended so that the step
is centered on at x. Adjacent points are connected
by a vertical line at their average x, that is, from
((x1+x2)/2,y1) to ((x1+x2)/2,y2). The input column
requires are the same as for plot styles lines
and points.
with histeps
If autoscale is in effect, it selects the xrange from the data rather than the steps, so the end points will
appear only half as wide as the others. See also
steps demo.
histeps is only a plotting style; gnuplot does not have the ability to create bins and determine their
population from some data set.
32 Histograms
The histograms style is only relevant to 2D plotting. It produces a bar chart from a sequence of parallel
data columns. Each element of the plot command must specify a single input data source (e.g. one
column of the input file), possibly with associated tic values or key titles. Four styles of histogram layout
are currently supported.
set style histogram clustered {gap }
set style histogram errorbars {gap } {}
set style histogram rowstacked
set style histogram columnstacked
The default style corresponds to set style histogram clustered gap 2. In this style, each set of
parallel data values is collected into a group of boxes clustered at the x-axis coordinate corresponding
to their sequential position (row #) in the selected datafile columns. Thus if datacolumns are
selected, the first cluster is centered about x=1, and contains boxes whose heights are taken from
the first entry in the corresponding data columns. This is followed by a gap and then a second
cluster of boxes centered about x=2 corresponding to the second entry in the respective data columns,
and so on. The default gap width of 2 indicates that the empty space between clusters is equivalent to
the width of 2 boxes. All boxes derived from any one column are given the same fill color and/or pattern
(see set style fill (p. 131)).