From 967173555da75c300f776a737738f8b01fd492f8 Mon Sep 17 00:00:00 2001
From: Julia Haas <83269984+juleshaas@users.noreply.github.com>
Date: Thu, 12 Oct 2023 09:21:31 +0200
Subject: [PATCH] change calculation of tree diameter (#63)

---
 .../v.trees.param.worker/v.trees.param.worker.py              | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/grass-gis-addons/m.analyse.trees/v.trees.param.worker/v.trees.param.worker.py b/grass-gis-addons/m.analyse.trees/v.trees.param.worker/v.trees.param.worker.py
index 8a66035..f06f58b 100644
--- a/grass-gis-addons/m.analyse.trees/v.trees.param.worker/v.trees.param.worker.py
+++ b/grass-gis-addons/m.analyse.trees/v.trees.param.worker/v.trees.param.worker.py
@@ -215,7 +215,7 @@ def crowndiameter(list_attr, treecrowns):
     grass.run_command(
         "v.to.db",
         map=treecrowns,
-        option="perimeter",
+        option="area",
         columns=col_diameter,
         quiet=True,
     )
@@ -224,7 +224,7 @@ def crowndiameter(list_attr, treecrowns):
         "v.db.update",
         map=treecrowns,
         column=col_diameter,
-        query_column=f"{col_diameter}/{math.pi}",
+        query_column=f"2*(sqrt({col_diameter}/{math.pi}))",
     )
     grass.message(_("Crown diameter was calculated."))
     return col_diameter