rbanick

Background

QGIS's Atlas feature and ArcGIS's Data Driven Pages allow you to create a series of maps, one per geography, based off a single map style. Titles, labels, and styles within the maps can be created based on the attributes of key layers and/or the scale of the map, imparting some customization and flexibility to an otherwise automated process. Atlas geographies can be points, polygons, and scales can be adjusted.

But what if you want to create multiple maps for a single geography, or multiple maps for multiple geographies? How can you vary not just the extent but the contents of what's shown?

This walkthrough will detail two complementary methods for filtering the display of datasets across multiple geographies using QGIS's Atlas Tool. This is a deep dive into a few specific Atlas techniques that I thought were poorly documented elsewhere and useful, not an exhaustive guide to the Atlas Tool. I have no idea if any or all of these techniques can be replicated using ArcGIS's Data Driven Pages.

rbanick

CREATE TABLE comparison AS
select aug29_clean.cluster, 
count(*) as total,
sum(case when aug29_clean.b_materials=exposure_matching.b_materials then 1 else 0 end) as building_materials,
sum(case when aug29_clean.b_levels=exposure_matching.b_levels then 1 else 0 end) as building_levels,
sum(case when aug29_clean.b_category=exposure_matching.b_category then 1 else 0 end) as building_type,
sum(case when aug29_clean.b_foundation=exposure_matching.b_foundation then 1 else 0 end) as building_foundation,
sum(case when aug29_clean.b_age=exposure_matching.b_age then 1 else 0 end) as building_age,
sum(case when aug29_clean.r_shape=exposure_matching.r_shape then 1 else 0 end) as roof_shape,
sum(case when aug29_clean.r_materials=exposure_matching.r_material then 1 else 0 end) as roof_materials

rbanick

# easy way

https://github.com/AmericanRedCross/OpenMapKitServer/blob/master/docs/api.md
and then
http://everygoodusernameistaken.tumblr.com/post/52805666711/exporting-openstreetmap-roads-to-shapefile

# longer way

## tar the folder

rbanick

-- You update the SRID for your table first. Then you reverse that update within a SQL query so you can transform the actual coordinates to their new EPSG. 
-- Otherwise you'll have Lat/Long coordinates for a metric projection or vice-versa.

SELECT Updategeometry_columnetrySRID('table','geometry_column',new_EPSG);
ALTER TABLE table
    ALTER COLUMN geometry_column TYPE geometry(geometry_type,new_EPSG) USING ST_Transform(ST_SetSRID(geometry_column,old_EPSG),new_EPSG);
SELECT ST_AsText(geometry_column) FROM table;

rbanick

import os
import fnmatch
import json 
import shutil

source_folder = 'your/survey/folder/directory'
osm_files = '/your/osm/files/folder'
fixed_folders = '/where/to/put/rescued/survey/folders'

def out(f, arr, name):

rbanick

Field Mapping Order of Operations

Attanagalu Oya Project, Sri Lanka

1. Select your area to cover and prepare a base map of that area in QGIS (to capture admin boundaries not in OSM).
2. Prepare field papers for this area.
3. Do one day pass through the area with field papers and GPS, mapping only roads, landuses, major points of interest and other features that will help orient map users.
4. Input this data into OSM.
5. After the data has been synchronized and reflected in the OSM map, prepare new Field Papers, OMK maps and OMK data after the data has been processed and the OSM map updated (this may take several hours).

rbanick

QGIS Atlas Techniques

Basics

Creating an Atlas Layer

1. Create a shapefile that includes ONLY the features you want to create an atlas of (e.g. only the districts you want maps of)
2. Open a new print composer. Give it a name you can remember, like 'Atlas'
3. Go to the 'Atlas Generation' tab and check the box next to "Generate Atlas".

rbanick

// Use Gists to store code you would like to remember later on
console.log(window); // log the "window" object to the console

rbanick

## create summary table

CREATE TABLE temp_table AS 
(select 
	 	count(id) AS features_per_ADMIN, 
		avg(master_table.thing_to_average) AS avg_thing_to_average, 
		sum(master_table.thing_to_sum) AS sum_thing_to_sum, 
		count(master_table.thing_to_count) AS count_thing_to_count, 
		COUNT(DISTINCT master_table.thing_to_count_distinct) AS cntd_thing_to_count_distinct, 	
		## ...add as many summary fields as you want here

rbanick

#### getting intersects of roads from a district. To eliminate bordering things using ST_Contains

DROP TABLE chitawan_roads_intersect;

CREATE TABLE chitawan_roads_intersect
WITH (OIDS)
AS
	SELECT osm_roads_4326.*
	FROM osm_roads_4326, districts
		WHERE