SOC 4650/5650 - Lecture-12 - Clip and Dissolve

Transcript

1. CLIP AND DISSOLVE INTRO TO GISC CHRISTOPHER PRENER, PH.D. SPRING 2019 WEEK 12 LECTURE 12
2. AGENDA 1. Front Matter 2. Clip 3. Dissolve 4. Back Matter INTRO TO GISC / WEEK 12 / LECTURE 12
3. 1 FRONT 
 MATTER
4. Due Next Lecture: Lab-11 (from today), PS-04 (from last lecture) 1. FRONT MATTER ANNOUNCEMENTS Due in Two Lectures: Lab-12 (from next week), PS-05 (from today) Final project draft materials are due next week!
5. CLIP 2
6. KEY TERM The clip tool is used to 
 edit geometric data 
 without modifying the underlying attributes. It is typically used with line and polygon data.
7. CLIP WITH POLYGONS (CONCEPTUAL) Input Features ID Shape Type 104 Polygon A 105 Polygon B 106 Polygon A 107 Polygon B 104 105 106 107 ID Shape Zone 23 Polygon 2 Clip Features 23
8. CLIP WITH POLYGONS (CONCEPTUAL) Output Features 104 105 106 23 ID Shape Type 104 Polygon A 105 Polygon B 106 Polygon A ID Shape Zone 23 Polygon 2 Clip Features
9. CLIP WITH LINES (CONCEPTUAL) Input Features ID Shape Type 104 Line Interstate 105 Line State 106 Line Interstate 107 Line Interstate 108 Line State 109 Line US 110 Line Interstate 111 Line Interstate 112 Line US 113 Line Interstate 114 Line State ID Shape 23 Polygon Clip Features 23
10. CLIP WITH LINES (CONCEPTUAL) Output Features ID Shape Type 108 Line State 109 Line US ID Shape 23 Polygon Clip Layer
11. ▸ Polygon data • All Census Tracts • Census Tract 124100 ▸ Line data - street centerlines 2. CLIP CLIP EXAMPLE
12. CLIP WITH LINES (EXAMPLE)
13. 3 DISSOLVE
14. KEY TERM The dissolve tool is used 
 to edit both the geometric 
 data and the underlying attributes by combining them based on a shared attribute. It is typically used with line and polygon data.
15. 3. DISSOLVE DISSOLVE POLYGONS This is the more common use for dissolve - a lower order polygon is dissolved into a higher order one. Tract CBG Shape 1 A Polygon 1 B Polygon 1 C Polygon Input Features Census 
 Block
 Group A Census 
 Block 
 Group B Census 
 Block 
 Group C
16. Census 
 Tract 3. DISSOLVE DISSOLVE POLYGONS This is the more common use for dissolve - a lower order polygon is dissolved into a higher order one. Tract Shape 1 Polygon Output Features
17. 3. DISSOLVE DISSOLVE LINES This is the less common use for dissolve - a lower order line is dissolved into a higher order one. Street Block Shape Main 101 Line Main 102 Line Main 103 Line Input Features 101 102 103
18. 3. DISSOLVE DISSOLVE LINES This is the less common use for dissolve - a lower order line is dissolved into a higher order one. 1 Street Shape Main Line Output Features
19. ▸ Polygon data • All census tracts • A group of census tracts in Downtown St. Louis ▸ We can use the STATEFP attribute for the dissolve since it is common across all of the tracts in the downtown layer. You may have to make your own attribute occasionally. 3. DISSOLVE DISSOLVE
20. DISSOLVE
21. DISSOLVE