def flatness_elekta(profile: SingleProfile):
"""The Elekta specification for calculating flatness"""
try:
dmax = profile.field_calculation(field_width=0.8, calculation='max')
dmin = profile.field_calculation(field_width=0.8, calculation='min')
except ValueError:
raise ValueError(
"An error was encountered in the flatness calculation. The image is likely inverted. Try inverting the image before analysis with <instance>.image.invert()."
)
flatness = 100 * (dmax / dmin)
lt_edge, rt_edge = profile.field_edges()
return flatness, dmax, dmin, lt_edge, rt_edge
def symmetry_pdq_iec(profile: SingleProfile):
"""Symmetry calculation by way of PDQ IEC"""
values = profile.field_values(field_width=0.8)
lt_edge, rt_edge = profile.field_edges(field_width=0.8)
max_val = 0
sym_array = []
for lt_pt, rt_pt in zip(values, values[::-1]):
val = max(abs(lt_pt / rt_pt), abs(rt_pt / lt_pt))
sym_array.append(val)
if val > max_val:
max_val = val
symmetry = 100 * max_val
return symmetry, sym_array, lt_edge, rt_edge
def symmetry_point_difference(profile: SingleProfile):
"""Calculation of symmetry by way of point difference equidistant from the CAX"""
values = profile.field_values(field_width=0.8)
lt_edge, rt_edge = profile.field_edges(field_width=0.8)
cax = profile.fwxm_center()
dcax = profile.values[cax]
max_val = 0
sym_array = []
for lt_pt, rt_pt in zip(values, values[::-1]):
val = 100 * abs(lt_pt - rt_pt) / dcax
sym_array.append(val)
if val > max_val:
max_val = val
symmetry = max_val
return symmetry, sym_array, lt_edge, rt_edge