Update CRS

app.py

@@ -78,6 +78,58 @@ with st.expander("EVI/EVI2 Parameters"):
 ############################################
 # Functions
 ############################################
+
+# Function of find best suited statewise EPSG code
+def find_best_epsg(geometry):
+    if geometry.geom_type == 'Polygon':
+        centroid = geometry.centroid
+    else:
+        st.error("Geometry is not Polygon !!!")
+        st.stop()
+    common_epsg_codes = [7756, #Andhra Pradesh
+                         7757, #Arunachal Pradesh
+                         7758, #Assam
+                         7759, #Bihar
+                         7760, #Delhi
+                         7761, #Gujarat
+                         7762, #Haryana
+                         7763, #HimachalPradesh
+                         7764, #JammuAndKashmir
+                         7765, #Jharkhand
+                         7766, #MadhyaPradesh
+                         7767, #Maharastra
+                         7768, #Manipur
+                         7769, #Meghalaya
+                         7770, #Nagaland
+                         7772, #Orissa
+                         7773, #Punjab
+                         7774, #Rajasthan
+                         7775, #UttarPradesh
+                         7776, #Uttaranchal
+                         7777, #A&N
+                         7778, #Chattisgarh
+                         7779, #Goa
+                         7780, #Karnataka
+                         7781, #Kerala
+                         7782, #Lakshadweep
+                         7783, #Mizoram
+                         7784, #Sikkim
+                         7785, #TamilNadu
+                         7786, #Tripura
+                         7787, #WestBengal
+                         7771, #NE India
+                         7755, #India
+                         ]
+
+    
+    for epsg in common_epsg_codes:
+      crs = pyproj.CRS.from_epsg(epsg)
+      area_of_use = crs.area_of_use.bounds  # Get the bounding box of the area of use
+
+      #check if centroid of polygon lies in teh bounds of the crs
+      if (area_of_use[0] <= centroid.x <= area_of_use[2]) and (area_of_use[1] <= centroid.y <= area_of_use[3]):
+          return epsg  # Return the best suitable EPSG code
+    
 def daterange_str_to_dates(daterange_str):
     start_date, end_date = daterange_str.split("-")
     start_date = pd.to_datetime(start_date)
@@ -101,10 +153,10 @@ def shape_3d_to_2d(shape):
     else:
         return shape
 
-
 def preprocess_gdf(gdf):
-    gdf = gdf.to_crs(epsg=7761)  # epsg for Gujarat
     gdf["geometry"] = gdf["geometry"].apply(shape_3d_to_2d)
+    epsg_code = find_best_epsg(gdf["geometry"])
+    gdf = gdf.to_crs(epsg=int(epsg_code))  #Find best EPSG code
     gdf["geometry"] = gdf.buffer(0)  # Fixes some invalid geometries
     return gdf
 
@@ -368,10 +420,11 @@ if isinstance(file_url, str):
 
 buffer = st.number_input("Buffer (m)", value=50, min_value=0, step=1)
 
-input_gdf = preprocess_gdf(gpd.read_file(file_url))
+
 if len(input_gdf) > 1:
     st.warning(f"Only the first polygon in the KML will be processed; all other geometries will be ignored.")
 
+input_gdf = preprocess_gdf(gpd.read_file(file_url))
 # input_geometry_idx = st.selectbox("Select the geometry", input_gdf.index, format_func=format_fn)
 
 for i in range(len(input_gdf)):