pyRobShrk’s gists

pyRobShrk / invdisttree.py

Created February 10, 2018 18:31

Inverse Distance & K-D Tree Interpolation

	""" invdisttree.py: inverse-distance-weighted interpolation using KDTree
	fast, solid, local
	https://stackoverflow.com/a/3119544
	"""
	from __future__ import division
	import numpy as np
	from scipy.spatial import cKDTree as KDTree
	# http://docs.scipy.org/doc/scipy/reference/spatial.html

	__date__ = "2010-11-09 Nov" # weights, doc

pyRobShrk / mlpIDW.py

Last active May 2, 2018 23:20

multiple linearly projected inverse distance weighting

	import numpy as np
	import pandas as pd

	#~~~~USER INPUT PARAMETERS~~~~
	maxNearPoints = 20
	anisotropyFactor = 15
	searchTransv = 200 #meters
	searchLongitud = searchTransv*anisotropyFactor #meters
	gridSize = 3 #meters
	invDistPower = 1

pyRobShrk / writeFieldAliases.py

Last active March 21, 2018 15:36

arcpy script to write field aliases based on an Excel lookup table using pandas

	# start with an excel table with two columns
	# first row should be headers "FIELD" and "ALIAS"
	# copy both columns to clipboard including headers
	# use copyFieldsToClipboard to get the list
	# optionally add a column called "RENAME" and run renameFields

	import pandas as pd

	def copyFieldsToClipboard(lyr):
	fieldList = [f.name for f in arcpy.ListFields(lyr)]

pyRobShrk / googlePolyline.py

Last active February 28, 2018 00:42 — forked from signed0/gist:2031157

Google Polyline encoder & decoder

	'''Provides utility functions for encoding and decoding linestrings using the
	Google encoded polyline algorithm.
	'''

	def encode_coords(coords):
	'''Encodes a polyline using Google's polyline algorithm

	See http://code.google.com/apis/maps/documentation/polylinealgorithm.html
	for more information.

pyRobShrk / Write Geojson To Feature Class.py

Created March 14, 2018 15:59 — forked from d-wasserman/Write Geojson To Feature Class.py

This gist is intended to share a sample worker function to write Geojson to an ArcGIS Feature Class using Arcpy.

	def write_geojson_to_records(geojson):
	"""Will write geojson to a list of dictionaries with geomtry keys holding coordinates and storing the properties
	to dictionaries."""
	gjson_data = json.loads(geojson, encoding='utf-8')
	records = []
	arc_print("Geojson being read by row...")
	for feature in gjson_data["features"]:
	try:
	row = {}
	row["geometry"] = feature["geometry"]

pyRobShrk / compressSHP.py

Last active March 21, 2018 17:05

ArcMap script to copy a shapefile into a new smaller shapefile (in memory)

	# Compress Shapefile by reducing Text Field lengths, dropping M and Z
	# Unfortunately .management.AlterField only works for unpopulated text fields
	# Process: Copy Table to NumPy array, Determine max length of text fields
	# Create blank feature with previous as template, alter text field length
	# Copy features to new feature class in memory
	import arcpy.management as mg
	import numpy as np

	def compressSHP(inSHP, outSHP):
	fields = [f.name for f in arcpy.ListFields(inSHP) if not f.name == 'Shape']

pyRobShrk / CalcAreaLength.bas

Created May 4, 2018 15:54

This module adds text to a free-form Excel line or polygon, which shows the length or area of that drawing in inches

	Sub CalcLength()
	'Subroutine calculates the distance of straight line or "scribble" line
	'It has not been tested in any other Office software, but it should work with minor modification
	'By Rob Sherrick, 4/12/2018

	Dim dpi As Integer
	dpi = Application.InchesToPoints(1)
	Length = 0
	A = 1
	On Error Resume Next

pyRobShrk / geoid.py

Last active November 14, 2022 22:40

Python classes to calculate geoid height in meters NAVD 88 (Geoid 12b) and EGM 96

	import numpy as np
	from scipy.interpolate import RectBivariateSpline as Spline
	import pygeodesy as geo
	from pygeodesy.ellipsoidalVincenty import LatLon

	class Geoid12B(): #NAD 83 Ellipsoid
	# https://www.ngs.noaa.gov/GEOID/GEOID12B/GEOID12B_CONUS.shtml
	# Download a Geoid Grid in little endian binary format ('g2012bu5.bin')
	def __init__(self, leBinFile):
	glamn, glomn, dla, dlo = np.fromfile(leBinFile,'<f8',4)

pyRobShrk / GIStable2Clipboard.py

Created August 6, 2018 21:19

ArcPy function to copy the attribute table to clipboard for pasting into Excel

	import pandas as pd
	def GIStable2Clipboard(inTable, exportFields="all"):
	desc = arcpy.Describe(inTable)
	if exportFields =="all":
	exportFields = [f.name for f in arcpy.ListFields(inTable) if not f.name == desc.shapeFieldName]
	aliases = [f.aliasName for f in arcpy.ListFields(inTable) if not f.name == desc.shapeFieldName]
	pd.DataFrame.from_records(arcpy.da.TableToNumPyArray(inTable,exportFields),
	index=desc.OIDFieldName, columns=aliases).to_clipboard()

pyRobShrk / encodeLongLatCoords.py

Last active January 5, 2022 17:57

Convert lat/long coordinates into an ascii string. Useful for database storage outside of geodata formats.

	# Objective: A system capable of encoding geographic points, and polylines in ASCII characters
	# Obviously Google and geohash have similar algorithms, but with limited precision
	#
	# A 24-bit integer can store binary integer values up to 16,777,215
	# Using PEM format, 24 bits can be represented as 4 base-64 characters with the alphabet:
	# ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/
	# A polyline can be represented by a string of characters,
	# where each 8 characters is a longitude/latitude location
	# For maximum flexibility, a polyline or point string is prefixed with three characters
	# The first two characters specifies the origin - the lower left corner of a MGRS GZD

Rob pyRobShrk