size

Sets the size of each x axis bin. Default behavior: If nbinsx is 0 or omitted, we choose a nice round bin size such that the number of bins is about the same as the typical number of samples in each bin. If nbinsx is provided, we choose a nice round bin size giving no more than that many bins. For date data, use milliseconds or "M" for months, as in axis.dtick. For category data, the number of categories to bin together (always defaults to 1).