Editing Multimodal distribution (section)

===Bimodality parameter===

This parameter (''B'') is due to Wilcock.<ref name=Wilcock1993>{{cite journal | last1 = Wilcock | first1 = PR | year = 1993 | title = The critical shear stress of natural sediments | journal = Journal of Hydraulic Engineering | volume = 119 | issue = 4| pages = 491–505 | doi=10.1061/(asce)0733-9429(1993)119:4(491)}}</ref>

<math display="block"> B = \sqrt{ \frac{ A_r }{ A_l } } \sum_i P_i </math>

where ''A''<sub>l</sub> and ''A''<sub>r</sub> are the amplitudes of the left and right peaks respectively and ''P''<sub>''i''</sub> is the logarithm taken to the base 2 of the proportion of the distribution in the i<sup>th</sup> interval. The maximal value of the ''ΣP'' is 1 but the value of ''B'' may be greater than this.

To use this index, the log of the values are taken. The data is then divided into interval of width Φ whose value is log 2. The width of the peaks are taken to be four times 1/4Φ centered on their maximum values.