"""Volume calculations"""
#pylint: disable=invalid-name
# The invalid name linting is disabled since this is a math heavy module
# it makes sense to use short names. Please still use sensible names for non
# mathematical variables
# TODO: Merchantable volume should call the gross total volume functions
from __future__ import division
import numpy as np
DEFAULT_UTILIZATIONS = {
"aw": {
"topDiamInsideBark": 7,
"stumpDiamOutsideBark": 13,
"stumpHeight": 0.3
},
"sw": {
"topDiamInsideBark": 7,
"stumpDiamOutsideBark": 13,
"stumpHeight": 0.3
},
"sb": {
"topDiamInsideBark": 7,
"stumpDiamOutsideBark": 13,
"stumpHeight": 0.3
},
"pl": {
"topDiamInsideBark": 7,
"stumpDiamOutsideBark": 13,
"stumpHeight": 0.3
}
}
def _gross_totalvolume_aw(basal_area, top_height):
''' White Aspen Gross Total Volume
Note that inputs may be scalars, or numpy arrays.
:param float basal_area: basal area
:param float top_height: top height
'''
a1 = 0.248718
a2 = 0.98568
a3 = 0.857278
a4 = -24.9961
tot_vol = a1 \
* (basal_area ** a2) \
* (top_height ** a3) \
* np.exp(1 \
+ (a4 / ((top_height ** 2) + 1)))
return tot_vol
def _gross_totalvolume_sw(basal_area, top_height):
'''White Spruce Gross Total Volume
Note that inputs may be scalars, or numpy arrays.
:param float basal_area: basal area
:param float top_height: top height
'''
b1 = 0.41104
b2 = 0.983108
b3 = 0.971061
tot_vol = b1 \
* (basal_area ** b2) \
* (top_height ** b3)
return tot_vol
def _gross_totalvolume_sb(basal_area, top_height):
'''Black Spruce Gross Total Volume
Note that inputs may be scalars, or numpy arrays.
:param float basal_area: basal area
:param float top_height: top height
'''
b1 = 0.48628
b2 = 0.982962
b3 = 0.910603
tot_vol = b1 \
* (basal_area ** b2) \
* (top_height ** b3)
return tot_vol
def _gross_totalvolume_pl(basal_area, top_height):
'''Lodgepole Pine Gross Total Volume
Note that inputs may be scalars, or numpy arrays.
:param float basal_area: basal area
:param float top_height: top height
'''
a1 = 0.194086
a2 = 0.988276
a3 = 0.949346
a4 = -3.39036
tot_vol = a1 \
* (basal_area ** a2) \
* (top_height ** a3) \
* np.exp(
1 + (a4 / ((top_height ** 2) + 1)))
return tot_vol
[docs]def gross_total_volume(species, *args):
"""Gross total volume
:param str species: species abbreviation
:param *args: additional arguments to species specific gross total
volume functions
"""
return {
'Aw': _gross_totalvolume_aw,
'Sw': _gross_totalvolume_sw,
'Sb': _gross_totalvolume_sb,
'Pl': _gross_totalvolume_pl,
}[species](*args)
def _merchantable_volume_aw(density, basal_area, top_height, total_volume,
stump_dob=13, top_dib=7, stump_height=0.3):
'''Merchantable volume for white aspen
Only new variables are the stump diameter outside bark, stump height and
top diameter inside bark The if below was used (and in other functions) to
avoid division by zero when density is zero, i.e., when the species is
absent in the plot.
:param float density: density
:param float basal_area: basal area
:param float top_height: top height
:param float StumpHeight: stump height
:param float TopDib: top diameter inside bark
:param float total_volume: Gross total volume
:param float StumpDOB: stump diameter outside bark
'''
k = (basal_area * 10000.0 / density) ** 0.5
b0 = 0.993673
b1 = 923.5825
b2 = -3.96171
b3 = 3.366144
b4 = 0.316236
b5 = 0.968953
b6 = -1.61247
k1 = total_volume * (k ** b0)
k2 = (
b1 \
* (top_height ** b2) \
* (stump_dob ** b3) \
* (stump_height ** b4) \
* (top_dib ** b5) \
* (k ** b6)
) + k
merch_vol = k1 / k2
return merch_vol
def _merchantable_volume_sb(density, basal_area, top_height, total_volume,
stump_dob=13, top_dib=7, stump_height=0.3):
'''Merchantable volume black spruce
The if below was used (and in other functions) to avoid division by zero
when density is zero, i.e., when the species is absent in the plot.
:param float density: density
:param float top_height: top height
:param float StumpDOB: stump diameter outside bark
:param float StumpHeight: stump height
:param float TopDib: top diameter inside bark
:param float total_volume: Gross total volume
'''
k = (basal_area * 10000.0 / density) ** 0.5
b0 = 0.98152
b1 = 0.678011
b2 = -1.10256
b3 = 4.148139
b4 = 0.511391
b5 = 1.484988
b6 = -3.26425
merch_vol = (total_volume * (k ** b0)) \
/ (
(b1 \
* (top_height ** b2) \
* (stump_dob ** b3) \
* (stump_height ** b4) \
* (top_dib ** b5) \
* (k ** b6)
) + k
)
return merch_vol
def _merchantable_volume_sw(density, basal_area, top_height, total_volume,
stump_dob=13, top_dib=7, stump_height=0.3):
'''Merchantable volume for white spruce
The if below was used (and in other functions) to avoid
division by zero when density is zero, i.e., when the
species is absent in the plot.
:param float density: density
:param float top_height: top height
:param float StumpDOB: stump diameter outside bark
:param float StumpHeight: stump height
:param float TopDib: top diameter inside bark
:param float total_volume: Gross total volume
'''
k = (basal_area * 10000.0 / density) ** 0.5
b0 = 0.996262
b1 = 7.021736
b2 = -1.77615
b3 = 1.91562
b4 = 0.4111
b5 = 1.024803
b6 = -0.80121
merch_vol = (total_volume * (k ** b0)) \
/ (
(b1 \
* (top_height ** b2) \
* (stump_dob ** b3) \
* (stump_height ** b4) \
* (top_dib ** b5) \
* (k ** b6)
) + k
)
return merch_vol
def _merchantable_volume_pl(density, basal_area, top_height, total_volume,
stump_dob=13, top_dib=7, stump_height=0.3):
'''Merchantable volume for lodgepole pine
The if below was used (and in other functions) to avoid division by zero
when density is zero, i.e., when the species is absent in the plot.
:param float density: density
:param float top_height: top height
:param float StumpDOB: stump diameter outside bark
:param float StumpHeight: stump height
:param float TopDib: top diameter inside bark
:param float total_volume: Gross total volume
'''
k = (basal_area * 10000.0 / density) ** 0.5
b0 = 0.989889
b1 = 1.055091
b2 = -0.19072
b3 = 4.915593
b4 = 0.42574
b5 = 1.006379
b6 = -4.87808
merch_vol = (total_volume * (k ** b0)) \
/ (
(b1 \
* (top_height ** b2) \
* (stump_dob ** b3) \
* (stump_height ** b4) \
* (top_dib ** b5) \
* (k ** b6)
) + k
)
return merch_vol
[docs]def merchantable_volume(species, *args, **kwargs):
"""Merchantable volume
:param str species: species abbreviation
:param *args: additional arguments to species specific gross total
volume functions
"""
return {
'Aw': _merchantable_volume_aw,
'Sw': _merchantable_volume_sw,
'Sb': _merchantable_volume_sb,
'Pl': _merchantable_volume_pl,
}[species](*args, **kwargs)
