Grain Axis Brackets

In some cases, one might wish to group similar grain sizes, for example, sand or ash grains. This is carried out by default for all of the available grain size presets discussed in the previous section, but can also be removed, or adjusted manually by passing a dictionary to the grain_brackets argument of sp.load().

This parameter has default values for all of the available grain size presets, which are illustrated below.

grain_brackets = {'sand': [3, 5], 'gravel': [6, 7.5]}
log = sp.load('tutorial.csv', grain_brackets=grain_brackets)
Sedimentary grain size brackets 
grain_brackets = {'ash': [1, 2.5], 'lapilli': [3, 4]}
log = sp.load('tutorial.csv', grain_brackets=grain_brackets)
Volcanic grain size brackets 
grain_brackets = {}
log = sp.load('tutorial.csv', grain_brackets=grain_brackets)
Geological grain size brackets

The grain brackets functionality can be removed by passing an empty dictionary to the grain_brackets argument:

log = sp.load('file.csv', grain_brackets={})

Alternatively, you can provide a custom dictionary to match either a preset or your own grain sizes provided in x_ticks_dict.

For example, to change the default ‘sedimentary’ preset’s brackets:

grain_brackets = brackets = {
    'powders': (1, 2),
    'sands': (3, 5),
    'rocks': (6, 7.5)
}
log = sp.load('file.csv', grain_brackets=grain_brackets)
Custom grain size brackets

Alternatively, we can specify a custom dictionary of grain sizes and brackets:

x_ticks = { 'mud': .5, 'silt': 1.5, 'v.f.': 3, 'f': 3.5, 'm': 4, 'c': 4.5, 'v.c.': 5, 'peb': 6, 'cob': 6.75, 'bld': 7.5 }
brackets = {
    'powders': (.5, 1.5),
    'sands': (3, 5),
    'rocks': (6, 7.5)
}
log = sp.load('file.csv', x_ticks_dict=x_ticks, grain_brackets=brackets)
Custom grain size brackets