README.md

v2r

Vector to Raster Interpolation Routines

Features

v2r contains two algorithms with an associated testing suite.

• Inverse Distance Weighting (IDW)
• Cleaner

IDW

The interpolation becomes more drastic as p increases.

Equation

$z_p= \frac{\displaystyle\sum_{i=1}^{n} (\frac {z_i}{d_i^p}) } {\displaystyle\sum_{i=1}^{n} (\frac {1}{d_i^p})}$

Read from txt file
./v2r idw -f [FILEPATH]

Read from geopackage
./v2r idw -f [FILEPATH] -g --layer [LAYERNAME] --field [FIELDNAME]

Default usage for one exponent
./v2r idw -f [FILEPATH] -g --layer [LAYERNAME] --field [FIELDNAME] --es [EXPONENT]

Usage for range of exponents
./v2r idw -f [FILEPATH] -g --layer [LAYERNAME] --field [FIELDNAME] --es [START] --ee [END] --ei [INCREMENT]

Flags

Shorthand	Full Name	Type	Default	Description
-c	--concurrent	bool	false	Run concurrently?
	--cx	int	200	Set chunk size in x-direction
	--cy	int	200	Set chunk size in y-direction
	--ee	float		Set end for exponent (exclusive)
	--ei	float	1.5	Set exponential increment for calculations between start and end
	--epsg	int	2284	Set EPSG
	--es	float	0.5	Set start for exponent (inclusive)
	--excel	bool	false	Perform an additional write to excel spreadsheet?
	--field	string		Set name of field in geopackage file
-f	--file	string	required	File to run
-g	--gpkg	bool	false	Read from gpkg (true) or txt file (false)?
	--layer	string		Set name of layer in geopackage file
	--outPath	string	data/idw	Set outfile directory
	--sx	float	100.0	Set step size in x-direction
	--sy	float	100.0	Set step size in y-direction

Notes

• txt file input requires special formatting (example idw_in.txt)
• cx, cy only used if --concurrent=true
• invalid chunk sizes are converted to 1/4 of respective direction (~16 subprocesses)
• epsg only used if --gpkg=false
• field, layer required if --gpkg=true
• not recommended to run ascii or excel prints for large datasets

Cleaner

This program cleans islands (dry spots) and voids (wet spots) that do not meet the tolerance thresholds.

Usage
./v2r clean -f [FILEPATH]

Flags

Shorthand	Full Name	Type	Default	Description
-a	--adjacent	int	8	Set adjacency type to include ordinal directions [4 | 8]
-c	--concurrent	bool	false	Run concurrently?
	--cx	int	2560	Set chunk size in x-direction
	--cy	int	2560	Set chunk size in y-direction
-f	--file	string	required	File to run
	--ti	float	40,000.0	Set tolerance level for islands (sq. footage)
	--tv	float	22,500.0	Set tolerance level for voids (sq. footage)

Notes

• monitor memory usage (process can use up to 80% of free memory)
• cx, cy only used if --concurrent=true
• cx, cy number of columns, rows to partition file into for subprocess calculations
• invalid chunk sizes are converted to 1/4 of respective direction (~16 subprocesses)

Testing Suite

Usage
go test ./...

Run Specific Test
go test ./features/idw

Test Locations

• features/idw
  • subtest name: "{ Serial | Conc }_step{ 1-1 | 2-2 }"
• features/cleaner
  • subtest name: "{ Serial | Conc }_T{ 4 | 9 }_A{ 4 | 8 }"
  • "T" is for tolerance island threshold
  • "A" is for adjacency type
• tools/processing
  • subtest name: "{ data | proj | xInfo | yInfo }"
  • tests geopackage reader

Notes

• outputs ascii files to compare against correct outputs

Logging

By default, logs are sent to Stdout at the INFO level.

Flags

Shorthand	Full Name	Type	Default	Description
-d	--debug	bool	false	Set logging level to DEBUG
-e	--error	bool	false	Set logging level to ERROR
-l	--log	bool	false	Log outputs to separate file

Notes

• output logs written to logs/
• sample log filename: 2022-24-06_22:06:25.txt
• if -d or -e are not passed, level=INFO used