barChart
Appends a vertical bar chart.
Each entry in series becomes one filled bar whose height is proportional to its value relative to the largest value in the set. A baseline axis line is stroked along the bottom of the plot. Bar captions are laid out in a row of equal-width weighted slots so every label sits centred under its bar, and — when showValues is on — the numeric value is drawn above each bar.
The whole drawing is emitted through freeDraw / text, so the output stays crisp vector at any zoom.
An empty series, or one whose values are all <= 0, draws nothing.
When showAxis is on, a baseline is stroked along the bottom. When gridLines is greater than 0, that many faint horizontal value-grid lines are drawn across the plot and the min (0) and max value are labelled at the left edge so the bar heights can be read against a scale.
Parameters
the bars, left to right.
total width of the plot area.
total height of the plot area (bars + value captions live inside this; the label row is added beneath it).
when true (default), draws each bar's value above it.
when true (default), strokes the baseline axis line.
number of faint horizontal value-grid lines (and the min/max axis labels). 0 (default) draws no grid.
colour of the baseline axis line.
colour of the faint value-grid lines.