Geocoding and Reverse Geocoding Addresses in QGIS - Revision history

Jacobjohnson: /* Attribute Table */

2021-12-21T15:25:46Z

Attribute Table

Jacobjohnson at 19:43, 20 December 2021

2021-12-20T19:43:36Z

Jacobjohnson: /* Reverse Geocoding */

2021-12-20T19:21:44Z

Reverse Geocoding

Jacobjohnson at 19:19, 20 December 2021

2021-12-20T19:19:07Z

Jacobjohnson: /* Attribute Table */

2021-12-20T18:30:05Z

Attribute Table

Jacobjohnson: /* Attributes */

2021-12-20T18:29:14Z

Attributes

Jacobjohnson at 18:26, 20 December 2021

2021-12-20T18:26:51Z

Jacobjohnson: /* Geocoding the Addresses */

2021-12-20T18:12:20Z

Geocoding the Addresses

Jacobjohnson: /* Geocoding the Addresses */

2021-12-20T18:12:03Z

Geocoding the Addresses

Jacobjohnson: /* Geocoding the Addresses */

2021-12-20T18:06:27Z

Geocoding the Addresses

@@ Line 67: / Line 67: @@
 ===Attribute Table===
 You'll notice that even though we have our latitude and longitude, their formatting in the attribute table is not ideal, as they are both located in the same column. To adjust the columns to show Lat and Long separately, open the attribute table and select the Field Calculator.
 [[File:table1.PNG]]

@@ Line 88: / Line 88: @@
 [[File:reverse3.PNG]]
 [[File:reverse4.PNG]]
+==Conclusion==
+Geocoding is a very simple, effective way to collect latitude and longitude coordinates which can be further used for GIS analysis, cartography, decision making workflow, transaction mash-up, or injected into larger business processes. Or, geocoding can be used in services such as routing and local search. The MMQGIS plugin within QGIS is one of the easiest and most user-friendly geocoding services available for GIS programs. The ease of use and access, combined with the freely available software makes QGIS an easy choice to execute address geocoding.
+==References==
+* ArcMap. What is geocoding?-ArcMap | Documentation. (n.d.). Retrieved December 20, 2021, from https://desktop.arcgis.com/en/arcmap/latest/manage-data/geocoding/what-is-geocoding.html
+* Goldberg, D. W. (n.d.). From Text to Geographic Coordinates: The Current State of Geocoding. Retrieved December 20, 2021, from https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.117.471
+* McKie, D. (n.d.). Geocoding using QGIS . Geocoding Using QGIS. Retrieved December 20, 2021, from http://www.davidmckie.com/Geocoding%20Using%20QGIS_New.pdf
+* University of Western Ontario. (n.d.). Process for Geocoding in QGIS  Using Google and OpenStreetMap Web Map Services. Geocoding Using QGIS. Retrieved December 20, 2021, from https://www.lib.uwo.ca/madgic/projects/gis/Geocoding%20Using%20QGIS.pdf
+* What is geocoding? definition and faqs. OmniSci. (n.d.). Retrieved December 20, 2021, from https://www.omnisci.com/technical-glossary/geocoding

@@ Line 84: / Line 84: @@
 * Input our restaurants CVS file as the layer input. Choose OpenStreetMap again for the web service.
 [[File:reverse2.PNG]]
+* We should the new "Reverse" feature layer aligned with our old point locations. To make sure they are correct, we can use the Identify tool to display the attributes.
+[[File:reverse3.PNG]]
+[[File:reverse4.PNG]]

@@ Line 74: / Line 74: @@
 * After creating our new fields, we should be able to see our changes in the attribute table.
 [[File:table3.PNG]]
+===Reverse Geocoding===
+Reverse geocoding is simply the process by which geographic coordinates are converted into a physical address.
+Since we have extrapolated our latitude and longitude coordinates from our addresses in the step above, we can  use these coordinates to check and make sure our data point locations line up correctly.
+* Open MMQGIS, and select Reverse Geocode.
+[[File:reverse1.PNG]]
+* Input our restaurants CVS file as the layer input. Choose OpenStreetMap again for the web service.
+[[File:reverse2.PNG]]

@@ Line 71: / Line 71: @@
 * We will create a new field, and call it X, for latitude. Change the “Output field type” to “Decimal number (real)”. And the “Precision”, 5. In the Expression field, type '''$X'''. Hit OK. Repeat for longitude, but call the field Y.
 [[File:table2.PNG]]
+* After creating our new fields, we should be able to see our changes in the attribute table.
+[[File:table3.PNG]]

@@ Line 64: / Line 64: @@
 * If we check our output CVS file, it will show us the addresses that were unable to be geocoded, for whatever reason.
 [[File:points3.PNG]]
+===Attributes===
+You'll notice that even though we have our latitude and longitude, their formatting in the attribute table is not ideal, as they are both located in the same column. To adjust the columns to show Lat and Long separately, open the attribute table and select the Field Calculator.
+[[File:table1.PNG]]
+* We will create a new field, and call it X, for latitude. Change the “Output field type” to “Decimal number (real)”. And the “Precision”, 5. Hit OK. Repeat for longitude, but call the field Y.
+[[File:table2.PNG]]

← Older revision		Revision as of 18:12, 20 December 2021
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	* If we check our output CVS file, it will show us the addresses that were unable to be geocoded, for whatever reason.		* If we check our output CVS file, it will show us the addresses that were unable to be geocoded, for whatever reason.
	[[File:~~points2~~.PNG]]		[[File:points3.PNG]]

@@ Line 60: / Line 60: @@
 * And if we open the Attribute Table, we see our geocoded addresses, along with some added descriptive attributes, including latitude and longitude.
+[[File:points2.PNG]]
+* If we check our output CVS file, it will show us the addresses that were unable to be geocoded, for whatever reason.
 [[File:points2.PNG]]

@@ Line 56: / Line 56: @@
 This tutorial will not cover how to geocode using Google's API key's, but it is as simple as selecting Google instead of OpenStreetMap, and inserting your API key in the required input box.
-* Now that we have applied our geocoding via MMQGIS, we should see our new feature layer containing our new geocoded point locations.
+* Now that we have applied our geocoding via MMQGIS, we should see our new feature layer containing our new geocoded point locations. It should be noted that the larger the dataset, or the more addresses used, will sometimes take much longer to geocode.
 [[File:points1.PNG]]