Hi Johannes, thanks so much for your reply! Apologies for my delayed response, I got pulled into another project this week. But I'm still hoping you can help!
PERC_COVER_FIELD and DOM_SPECIES_FIELD are both fields from the input table.
In fact, here's the full script. I'm sure that will be more helpful. Any other suggestions?
import arcpy
# GLOBAL VARIABLES
POINT_ID_FIELD = 'AGCP___Wetland_Determination_Data_Form_v2.sampling_point'
PERC_COVER_FIELD = 'herb_stratum_repeat.abs_perc_cover_herb'
DOM_SPECIES_FIELD = 'herb_stratum_repeat.dom_species_herb'
def unique_values(table, field):
""" Create a list that contains all the unique Sampling_Point id's in the table."""
with arcpy.da.SearchCursor(table, [field]) as cursor:
return sorted({row[0] for row in cursor}) # using a set eliminates duplicates
def calc_veg_dom(perc_cover_values, stratum_layer):
"""Applies the 50/20 rule for calculating vegetation dominance. The function creates a list that identifies the
percent values that are for dominant species for a specific sampling point."""
for sample_id, sample_list in perc_cover_values.items():
total_cover = sum(perc_cover_values[sample_id])
perc_cover_50 = total_cover * 0.5
perc_cover_20 = total_cover * 0.2
dom_list = []
for item in sample_list:
dom_list.append(item)
# stop adding items to the list. All values that are in this list are dominant species (50% rule)
if sum(dom_list) > perc_cover_50:
break
# Identify the species that will be evaluated for the 20% rule.
# Creating a copy of the original sample_id list so we do not modify the original
remaining_vals = list(perc_cover_values[sample_id])
for item in dom_list:
if item in remaining_vals:
remaining_vals.remove(item)
for item in remaining_vals:
if item in dom_list and item < perc_cover_20:
dom_list.append(item)
if item >= perc_cover_20:
dom_list.append(item)
arcpy.management.SelectLayerByAttribute(stratum_layer, "NEW_SELECTION",
f"{POINT_ID_FIELD} = '{sample_id}'")
fields = (PERC_COVER_FIELD, DOM_SPECIES_FIELD)
exit()
with arcpy.da.SearchCursor(stratum_layer, fields) as cursor:
for row in cursor:
print(row)
if int(row[0]) in dom_list:
arcpy.management.CalculateField(stratum_layer, DOM_SPECIES_FIELD, "'Y'", "PYTHON3")
print(f"{int(row[0])} is dominant")
else:
arcpy.management.CalculateField(stratum_layer, DOM_SPECIES_FIELD, "'N'", "PYTHON3")
print(f"{int(row[0])} is not dominant")
###########################################################################################################
def main():
fc = arcpy.GetParameterAsText(0)
stratum_table = arcpy.GetParameterAsText(1)
# Make Layer and Table View for the Join
fc_layer = arcpy.MakeTableView_management(fc, "fc_lyr")
stratum_layer = arcpy.MakeTableView_management(stratum_table, "stratum_lyr")
# Join feature class to stratum table based on the parentglobalID and globalID
arcpy.AddJoin_management(stratum_layer, "parentglobalid", fc_layer, "globalid", "KEEP_ALL")
point_id_list = unique_values(stratum_layer, POINT_ID_FIELD)
perc_covers_dict = {}
for id in point_id_list:
perc_covers_list = []
# Select features based on unique "Sampling_Point" name
arcpy.management.SelectLayerByAttribute(stratum_layer, "NEW_SELECTION", f"{POINT_ID_FIELD} = '{id}'")
# Create a dictionary that has all % cover numbers (value) in a list for a sampling ID (key)
with arcpy.da.SearchCursor(stratum_layer, PERC_COVER_FIELD) as cursor:
for row in cursor:
perc_covers_list.append(int(row[0]))
perc_covers_list.sort(reverse=True) # sort values from highest to lowest
perc_covers_dict[id] = perc_covers_list # adds the list as the value for each key (sample id) in a dict
calc_veg_dom(perc_covers_dict, stratum_layer)
if __name__ == "__main__":
main()
Best,
Katie
“The goal is not simply to ‘work hard, play hard.’ The goal is to make our work and our play indistinguishable.”
- Simon Sinek
