To position the array somewhere else on the graph, the origin keyword directs
gnuplot to position the lower left point of the array at a point specified by a
tuple. The tuple should be a double for plot and a triple for splot.
For example, origin=(100,100):(100,200) is for two records in the file and
intended for plotting in two dimensions. A second example, origin=(0,0,3.5),
is for plotting in three dimensions.