Latest Contributions by forestknutsen1

I have an area I would like to map. The extent of the area is approximately: -147 to -141 and 69.5 N to 70.5 N (North East Alaska). It falls right between two state plane zones and also between two UTM zones. For now, I just took the Alaska Albers projection and changed the central meridian to -144 and set the standard parallels to 69.6 and 69.8.  So, I am wondering if this is the best choice. Should try and tweak a UTM zone? Or maybe a Lambert projection? I am just trying to pick something that will minimize distortion and be focused on the area of interest. Thanks, Forest ... View more

I need to make a script tool that will consolidate attributes from many rows into to one across a number of columns. The tool will need to be able to let the user select the field "key" field as well as the fields that will be consolidated. I made a quick mockup table as my input table (it has been processed with spatial sort so that parts of the key features that are spatially adjacent to each other are also in adjacent rows in the table).   Mockup table. It has land ownership and PLSS (Public Land Survey System) MTRS (meridian township range section) information. Key_Feature Owner MTR SECTION MTRS MER Facility 1 Private U009N008E 33 U009N008E33 U Facility 1 Federal U009N008E 33 U009N008E33 U Facility 1 Private U009N008E 34 U009N008E34 U Facility 1 Federal U009N008E 34 U009N008E34 U Facility 1 Private U008N008E 4 U008N008E04 U Facility 2 Private U008N008E 3 U008N008E03 U The output should look like this. Key_Feature MTRS Owner Facility 1 U, T09N, R08E: 33, 34 U, T08N, R08E: 4 Federal, Private Facility 2 U, T08N, R08E: 3 Private The question: I would like input on the best method to get the result. And if there are any out of the box Arc tools that I could leverage... My first pass at this was to use arcpy.da.SearchCursor and iterate over the input table and check to see if the current row's key feature is the same as the previous row's key feature. If so, then add it to a string variable. When the key features do not match write the string variable and other fields to the output file. The MTRS roll up is a little more complex because sections needs to rolled up for each unique MTR associated with the key feature. It feels a little wired because you are always looking back in rows as you iterate over the table. So, I used a number of temp_last variables for key features, MTRS, etc. I was thinking that it would be better to read the whole table into a list of lists and then use that to generate the output. That way I could use indexing to look at the next and last rows without having to use the temp_last variables. The below code I made for a similar one off. import arcpy import os arcpy.env.overwriteOutput = True in_path = r"xxxx" out_path ="xxxx" def tsv_write(tsv_row):     for item in tsv_row:         tsv.write(item + "\t")     tsv.write("\n") def rollup(rollup_list):     rollup_list = set(rollup_list)     rollup_list = list(rollup_list)     rollup_list.sort()     rollup_str = ""     for sec in rollup_list:         rollup_str = rollup_str + str(sec) + ", "     rollup_str = rollup_str[:-2]     return rollup_str def from_to_fix(x):     x = round(x, 1)     x = str(x)     return x search_cursor = arcpy.da.SearchCursor(in_path, ["Main_LandOwnership_MTRS_Mbook_Meridian",                                                 "Main_LandOwnership_MTRS_Mbook_Town_Range",                                                 "Main_LandOwnership_MTRS_Mbook_SECTION",                                                 "Main_LandOwnership_MTRS_Mbook_F_MP",                                                 "Main_LandOwnership_MTRS_Mbook_T_MP",                                                 "Main_LandOwnership_MTRS_Mbook_Index_Order",                                                 "Main_LandOwnership_MTRS_Mbook_ROW_Designation"]) tsv = open(out_path, "w") meridian_last = None township_last = None f_mile_last = None t_mile_last = None owner_last = None township_list = [] township_section_list = [] first_row_flag = True township_append_flag = True section_list = [] index_order_list = [] for row in search_cursor:     meridian = row[0]     township = row[1]     section = row[2]     f_mile = row[3]     t_mile = row[4]     index_order = row[5]     owner = row[6]     if first_row_flag:         township_last = township         f_mile_last = f_mile         t_mile_last = t_mile         owner_last = owner         first_row_flag = False     if township == township_last:         township_append_flag = True         section_list.append(int(section))     else:         township_append_flag = False         section_rollup = rollup(section_list)         township_section_list.append(township_last + ": " + section_rollup)         section_list = []         section_list.append(int(section))     if f_mile == f_mile_last:         index_order_list.append(int(index_order))     else:         index_order_rollup = rollup(index_order_list)         write_flag = True         for trs in township_section_list:             if write_flag:                 write_flag = False                 print [from_to_fix(f_mile_last), from_to_fix(t_mile_last), trs, owner_last, index_order_rollup]                 tsv_write([from_to_fix(f_mile_last), from_to_fix(t_mile_last), trs, owner_last, index_order_rollup])             else:                 print ["", "", trs, "", ""]                 tsv_write(["", "", trs, "", ""])         township_section_list = []         index_order_list = []         index_order_list.append(index_order)     if meridian != meridian_last:         print meridian         tsv_write([meridian])         print ["From MP", "To MP", "MTRS", "Ownership", "Map Book Sheet"]         tsv_write(["From MP", "To MP", "MTRS", "Ownership", "Map Book Sheet"])     meridian_last = meridian     township_last = township     f_mile_last = f_mile     t_mile_last = t_mile     owner_last = owner if not township_append_flag:     township_section_list.append(township_last + ": " + str(int(section))) index_order_rollup = rollup(index_order_list) write_flag = True for trs in township_section_list:     if write_flag:         write_flag = False         print [from_to_fix(f_mile_last), from_to_fix(t_mile_last), trs, owner_last, index_order_rollup]         tsv_write([from_to_fix(f_mile_last), from_to_fix(t_mile_last), trs, owner, index_order_rollup])     else:         print ["", "", trs, "", ""]         tsv_write(["", "", trs, "", ""]) township_section_list = [] index_order_list = [] index_order_list.append(index_order) tsv.close() ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Thanks for any input! Forest ... View more

I am wondering about WGS84 as we move through time. My understanding is that any given spot on the earth's surface latitude and longitude will change over time in this system. There are two sources of change: 1) NGA (National Geospatial-Intelligence Agency) will periodically shift the center of the WGS84 ellipsoid to better align with their current best guess for the center of the earth's mass (I think they are using a geoid to find the center of mass). At which time the will release a new version of the WGS84 and note the GPS weeks in the name, e.g. WGS84 (G1150). 2) WGS84 is not locked to any land mass but to the stars. So, as the tectonic plates drift around on the earth's mantle a location on the earth's surfaces can change over time. Does that sound right? So, when I select WGS84 as my GCS what version of WGS84 am I getting? WGS84 (G873) WGS84 (G1150) WGS84 (G1674) WGS84 (G1762) Something else? Thanks! Forest ... View more