From bc4227342ec6d46bf0049966659b6f33273674ed Mon Sep 17 00:00:00 2001
From: tomrink <rink@ssec.wisc.edu>
Date: Wed, 1 Sep 2021 15:51:06 -0500
Subject: [PATCH] snapshot...
---
modules/util/lon_lat_grid.py | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/modules/util/lon_lat_grid.py b/modules/util/lon_lat_grid.py
index 66254434..0cf2d2c7 100644
--- a/modules/util/lon_lat_grid.py
+++ b/modules/util/lon_lat_grid.py
@@ -19,7 +19,7 @@ class MyGenericException(Exception):
class LonLatGrid:
# grd_lons, grd_lats: the longitude, latitude of each grid point (must be 2D grids), must have same shape
# Incoming longitude must be in range: 0 - 360 degrees
- # Can have NaN for off Earth grid points.
+ # Can have NaN for off Earth grid points (these are handled internally).
def __init__(self, grd_lons, grd_lats):
if grd_lons.shape != grd_lats.shape:
raise MyGenericException('incoming lons,lats must have same shape')
@@ -50,9 +50,10 @@ class LonLatGrid:
# locate nearest neighbor for incoming target in earth coordinates (Should not have NaNs)
# lons, lats can be flat or 2D
+ # closeness_threshold: if < distance of located_point to target, return off grid
# incoming longitude must be in range: 0 - 360 degrees
# returns NN indexes relative to the grid determined in the ctr.
- def value_to_index(self, lons, lats):
+ def value_to_index(self, lons, lats, closeness_threshold=2000):
if lons.shape != lats.shape:
raise MyGenericException('incoming lons,lats must have same shape')
@@ -65,8 +66,9 @@ class LonLatGrid:
xy = np.stack([lons, lats], axis=1)
dist, indices = self.kd.query(np.deg2rad(xy))
+ dist *= 6370000 # convert unit radius to meters
- valid = indices < self.map_indexes.size
+ valid = (indices < self.map_indexes.size) & (dist < closeness_threshold)
indices = indices[valid]
return self.map_indexes[indices], indices
--
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