GEOG 315, GIS Programming, Fall 2020; Lecture 4

Transcript

1. GEOG 315: GIS Programming and Web Mapping Lecture 4 – Geoprocessing, finally
2. GEOG 315: GIS Programming and Web Mapping Lecture 4 – Geoprocessing, finally For Today… 1. Some housekeeping 2. Geoprocessing, done three ways: 2a. With ArcMap/ArcPro Dialogs 2b. With Modelbuilder 2c. With Python
3. Some Items to Review… The things that are in a for loop get done every time through that loop. …so think carefully about what’s in the loop at what’s not!
4. For Loops [for every item in a list, do something to that item] here’s a plate, two glasses, a salad bowl, a spatula, a knife, three forks, a cutting board, six spoons, and a crock pot
5. For Loops [for every item in a list, do something to that item] here’s a plate, two glasses, a salad bowl, a spatula, a knife, three forks, a cutting board, six spoons, and a crock pot Make soapy water for each dish in the list of dishes: wash dish with sponge rinse with hot water place in drying rack
6. For Loops [for every item in a list, do something to that item] for each dish in the list of dishes: make soapy water wash dish with sponge rinse with hot water place in drying rack make soapy water for each dish in the list of dishes: wash dish with sponge rinse with hot water place in drying rack
7. For Loops [for every item in a list, do something to that item] for each dish in the list of dishes: make soapy water wash dish with sponge rinse with hot water place in drying rack Make soapy water for each dish in the list of dishes: wash dish with sponge rinse with hot water place in drying rack This one is efficient This one takes forever
8. Some Items to Review… The things that are in a for loop get done every time through that loop. …so think carefully about what’s in the loop at what’s not! How can we tell what’s in this loop?
9. Some Items to Review… The things that are in a for loop get done every time through that loop. …so think carefully about what’s in the loop at what’s not! How can we tell what’s in this loop?
10. Some Items to Review… The things that are in a for loop get done every time through that loop.
11. Some Items to Review… The things that are in a for loop get done every time through that loop.
12. Some Items to Review… The things that are in a for loop get done every time through that loop.
13. Some Items to Review… You don’t need to turn in code that produces errors/the wrong output!
14. Some Items to Review… You don’t need to turn in code that produces errors/the wrong output!
15. Some Items to Review… You don’t need to turn in code that produces errors/the wrong output*! *Unless you’re unable to get the answer! Then turn in what you’ve got (and comment it) so I can give partial credit
16. GEOG 315: GIS Programming and Web Mapping Lecture 4 – Geoprocessing, finally For Today… 1. Some housekeeping 2. Geoprocessing, done three ways: 2a. With ArcMap/ArcPro Dialogs 2b. With Modelbuilder 2c. With Python
17. 2. Geoprocessing, done three ways: 2a. With ArcMap/ArcPro Dialogs
18. 2. Geoprocessing, done three ways: 2a. With ArcMap/ArcPro Dialogs
19. 2. Geoprocessing, done three ways: 2a. With ArcMap/ArcPro Dialogs REQUIRED INPUTS This tool takes 7 inputs 3 are required 4 are optional
20. 2. Geoprocessing, done three ways: 2a. With ArcMap/ArcPro Dialogs REQUIRED INPUTS This tool takes 7 inputs 3 are required 4 are optional
21. 2. Geoprocessing, done three ways: 2a. With ArcMap/ArcPro Dialogs REQUIRED INPUTS This tool takes 7 inputs 3 are required 4 are optional
22. 2. Geoprocessing, done three ways: 2a. With ArcMap/ArcPro Dialogs This is great – but in reality I… 1.downloaded the elevation data 2.reprojected it from lat/long to meters (project raster) 3.hillshaded it (hillshade) 4.contoured it (contour)
23. 2. Geoprocessing, done three ways: 2a. With ArcMap/ArcPro Dialogs If I wanted to do this for ten (or 20, 100, 200) DEMs, it would get old quickly.
24. 2. Geoprocessing, done three ways: 2a. With ArcMap/ArcPro Dialogs Batch Processing can help with this, but only for one tool at a time.
25. 2. Geoprocessing, done three ways: 2b. With Model Builder I specify input and output dataset names and “link” tools together to form a workflow
26. 2. Geoprocessing, done three ways: 2b. With Model Builder Modelbuilder exists in ArcPro too. It’s a bit clunky.
27. 2. Geoprocessing, done three ways: 2b. With Model Builder Modelbuilder exists in ArcPro too. It’s a bit clunky. But Model Builder still requires that we tell it every input filename, intermediate filename, and output filename!
28. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy You can access Python from both ArcMap and ArcPro
29. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy Python shell in ArcMap and Pro
30. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy Python shell in ArcMap and Pro Pro also has Jupyter! …but it’s easier to save notebooks using regular Jupyter
31. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy Let’s look at the contour tool more closely. Anybody ever click this button?
32. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy Let’s look at the contour tool more closely. Anybody ever click this button?
33. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy REALLY HELPFUL INFORMATION
34. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy HOW TO MAKE A PYTHON STATEMENT WITH THIS TOOL
35. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy “PYTHON WINDOW” “STAND-ALONE SCRIPT” What’s the difference? You can run #1 in the PYTHON WINDOW You can run #2 in JUPYTER
36. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy This will run in ArcMap/Pro if you have the Python Window open
37. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy This will run in Jupyter AND MORE IMPORTANTLY You can send this script to anyone with ArcMap/Pro and they can run it too.
38. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy Let’s talk about what’s going on here – and you’ll try this in lab. import arcpy #import the arcpy module #just like math, datetime, random
39. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy Let’s talk about what’s going on here – and you’ll try this in lab. from arcpy.sa import * # import all the tools (*) # from spatial analyst toolbox
40. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy Let’s talk about what’s going on here – and you’ll try this in lab. env.workspace = “C:/sapyexamples/data” # define the workspace (aka ‘environment’) where # we’re going to read/write files
41. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy Let’s talk about what’s going on here – and you’ll try this in lab. Contour(“elevation”, “C:/sapyexamples/output/outcontours.shp, 200,0) # function(in_raster,out_polyline_features, # contour_interval, base_contour)
42. 2. Geoprocessing, done three ways: 2c. With Python/ArcPy Let’s talk about what’s going on here – and you’ll try this in lab. Contour(“elevation”, “C:/sapyexamples/output/outcontours.shp, 200,0) # run the contour function on “elevation”, output the # result to “outcontours.shp, use a contour interval of # 200, and a base contour of 0
43. Lab this week will look a little different. You’ll work through an exercise 1. Geoprocessing with dialog box tools 2. Geoprocessing with model builder 3. Geoprocessing with the Python window You’ll demonstrate all three of these in homework 1. Geoprocessing with dialog box tools 2. Geoprocessing with model builder 3. Geoprocessing with the Python window A single .zip folder with three screenshots (in the Jupyter assignment) A single .zip folder with three geodatabases, a toolbox, and a Jupyter notebook (in the homework assignment)