From 0a7a46fa6373e8472473c44c2f5be67430006cee Mon Sep 17 00:00:00 2001
From: alanphys <alanphys@yahoo.co.uk>
Date: Thu, 11 Mar 2021 09:21:54 +0200
Subject: [PATCH] commit for rebase

---
 pylinac/fieldparams.py | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/pylinac/fieldparams.py b/pylinac/fieldparams.py
index 2e2af498c..73068c164 100644
--- a/pylinac/fieldparams.py
+++ b/pylinac/fieldparams.py
@@ -9,7 +9,7 @@
 
 import matplotlib.pyplot as plt
 import numpy as np
-import math
+from scipy.interpolate import interp1d
 
 from pylinac.core.utilities import open_path
 from .core.exceptions import NotAnalyzed
@@ -159,8 +159,19 @@ def penumbra_slope_right_infl(profile: SingleProfile, *args):
 
 # Dose point values ----------------------------------------------------------------------------------------------------
 def dose_point_left_20(profile: SingleProfile, *args):
-    left_edge = 0.2*left_edge_infl(profile)*profile.dpmm + profile.center()
-    return
+    """Dose value at 20% of field size from CAX"""
+    left_edge_idx = profile.infl_points(pen_width, 'left')[0]
+    if norm in ['max', 'max grounded']:
+        cax_idx, cax_val = profile.fwxm_center(x=50, interpolate=interpolate)
+    else:
+        cax_idx, cax_val = profile.center()
+    dose_idx = cax_idx - (cax_idx - left_edge_idx)*0.2
+    if interpolate:
+        ydata_f = interp1d(profile._indices, profile.values, kind=profile.interpolation_type)
+        dose_val = ydata_f(dose_idx)
+    else:
+        dose_val = profile.values[round(cax_idx)]
+    return 100*dose_val/cax_val
 
 
 # Field flatness parameters --------------------------------------------------------------------------------------------
@@ -391,7 +402,8 @@ def deviation_max(profile: SingleProfile, ifa: float = 0.8):
     'left penumbra: {:.1f} mm': penumbra_left_infl,
     'right penumbra: {:.1f} mm': penumbra_right_infl,
     'left penumbra slope {:.1f} %/mm': penumbra_slope_left_infl,
-    'right penumbra slope {:.1f} %/mm': penumbra_slope_right_infl
+    'right penumbra slope {:.1f} %/mm': penumbra_slope_right_infl,
+    'left dose point 20%: {:.1f} %': dose_point_left_20
 }
 # ----------------------------------------------------------------------------------------------------------------------
 # End of predefined protocols - Do not change these. Instead copy a protocol, give it a new name, put it after these