Welcome to Methods 3, Lecture 13

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Methods 3

Final projects

Final projects

Presentations 12/8

Final projects

Final submission 12/10

OpenStreetMap

open data

open data

data that is:

• accessible (online, in a widely-used format)

open data

data that is:

• accessible (online, in a widely-used format)
• licensed freely

open data

data that is:

• accessible (online, in a widely-used format)
• licensed freely
• usually created by a large entity

data.cityofnewyork.us/Business/Filming-Locations-Scenes-from-the-City-/qb3k-n8mm

collaborative data

source

what is OpenStreetMap (OSM)?

show me the way

"the free wiki map of the world"

source

source

source

source

source

started in 2004 in the UK

started in 2004 in the UK

first State of the Map conference in 2007

started in 2004 in the UK

first State of the Map conference in 2007

over 1 million registered users in 2013

started in 2004 in the UK

first State of the Map conference in 2007

over 1 million registered users in 2013

over 4 million registered users in 2017

source

source

license

license

Open Database License (ODbL)

source

what does the data look like?

shapes

• nodes (points)
• ways (lines)
• closed ways (polygons)

nodes, ways, closed ways

are just shapes with no meaning until you give them attributes, as in any GIS

so you have to add attributes

an attribute table wouldn't work because:

• there would be thousands of columns

an attribute table wouldn't work because:

• there would be thousands of columns
• and most of those columns would be empty (eg 'electrified')

an attribute table wouldn't work because:

• there would be thousands of columns
• and most of those columns would be empty (eg 'electrified')
• what you could map would be predetermined

tags

key-value pairs

tags

leisure=park

tags

name=Union Square West

tags

we make them up as we go!

folksonomy

folksonomy

a collaborative system of categorization

you can tag things any way you want

source

source

source

source

let's do a little mapping

go to openstreetmap.org

sign up for an account

go somewhere you know, click Edit and look for something unmapped

(buildings are easy if you don't find something else)

looking for something to map?

source

filtering data

here's some data to follow along with

sometimes you have more data than you need

or you want to do something different with data depending on attribute values

previously, we've selected by expression

then exported that selection

another way

you could do this as many times as you like

the data isn't duplicated—it uses the same file on your computer

you can filter by text (but be careful)

ilike: "fuzzy" matching

i is short for "ignore case"

% matches any text

if you're only filtering to set styles, there might be a better way

rule-based styles

like filtering and styling that filtered layer, but you don't have duplicate layers