
A command to draw a histogram from the rows in the selected TableOfReal object.
The histogram will consist of groups of bars. The number of groups will be determined by the number of selected columns from the table, while the number of bars within each group will be determined from the number of selected rows.
The following arguments are all relative to the width of a bar in the histogram.
If you want to put the labels yourself you will need the following information.
The width of a bar is determined as follows:
width = 1 / (nc · nr + 2 · hoffset + (nc  1)· intergroup +nc·(nr 1)· interbar), 
where nc is the number of columns (groups) to draw, nr is the number of rows to draw (the number of bars within a group), hoffset is the horizontal offset, intergroup the distance between each group and interbar the distance between the bars within a group.
The spacing between the bars drawn from a row:
dx = (intergroup + nr + (nr 1) · interbar) * width 
The first bar for the kth row starts at:
x1 = hoffset · width + (k  1) · (1 + interbar) · width 
© djmw 20030619