Class 10 | Methods 3

Welcome to Methods 3, Lecture 10

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let's talk about project progress

show what you have so far
talk about what's going well
talk about roadblocks

come back prepared to share one concrete piece of progress a group member made

so how does a web map work?

(a few of these slides are adapted from these excellent Maptime slides)

most webmaps start with a basemap

tiles are 256 x 256 pixel images

they use the same zoom, x, and y values, so they're interchangeable

as you zoom in, the number of tiles quadruples

if you made tiles for all of zoom 18 you'd have nearly 69 billion images

that's why browsers only load what you need to see

source

each tile is just an image on the internet

http://{s}.tile.stamen.com/toner/{z}/{x}/{y}.png

http://a.tile.stamen.com/toner/0/0/0.png

these tiles use OpenStreetMap data

+ CartoCSS

so how do you make base maps?

in theory you can make tiles on your own

but many mapmakers turn to Mapbox

Mapbox provides modified OpenStreetMap data

not free, but free up to a point

source

creating styles in Mapbox

like most GISs, Mapbox maps are layer-based

layers are grouped into similar feature types, a layer group is called a component

you can change all of the layers in a component simultaneously

or you can view the layers that make up that component

layers have a lot more settings than components

by default, a layer in a component is locked

you can "override" individual settings and change them

not sure which component or layer a feature is on?

want to see exactly which features are in a layer?

first, go to the layer

green features will appear on the map, pink are on the layer but filtered out

click a feature to see the data behind it

some settings can't be changed without "ejecting" a layer from a component

for the most part, cartographic conventions hold with basemaps

scale
hierarchy
color
symbology

but with basemaps, be aware that zooming and panning change how it will be viewed

using Mapbox tiles in Carto

you can add your own data to Mapbox basemaps

for example, when you have too much data to put in Carto, and you don't want popups on the data

I recommend adding data as a tileset

1. Upload data (such as a zipped shapefile)

2. Add the tileset to your style

Methods 3

let's talk about project progress

let's talk about project progress

come back prepared to share one concrete piece of progress a group member made

so how does a web map work?

most webmaps start with a basemap

basemaps are tiled

tiles are 256 x 256 pixel images

they use the same zoom, x, and y values, so they're interchangeable

as you zoom in, the number of tiles quadruples

if you made tiles for all of zoom 18 you'd have nearly 69 billion images

that's why browsers only load what you need to see

each tile is just an image on the internet

these tiles use OpenStreetMap data

+ CartoCSS

so how do you make base maps?

it depends!

in theory you can make tiles on your own

but many mapmakers turn to Mapbox

Mapbox provides modified OpenStreetMap data

not free, but free up to a point

creating styles in Mapbox

like most GISs, Mapbox maps are layer-based

layers are grouped into similar feature types, a layer group is called a component

you can change all of the layers in a component simultaneously

or you can view the layers that make up that component

layers have a lot more settings than components

by default, a layer in a component is locked

you can "override" individual settings and change them

not sure which component or layer a feature is on?

click it!

want to see exactly which features are in a layer?

first, go to the layer

click Select Data

green features will appear on the map, pink are on the layer but filtered out

click a feature to see the data behind it

some settings can't be changed without "ejecting" a layer from a component

in-class exercise

for the most part, cartographic conventions hold with basemaps

but with basemaps, be aware that zooming and panning change how it will be viewed

using Mapbox tiles in Carto

in-class exercise

you can add your own data to Mapbox basemaps

for example, when you have too much data to put in Carto, and you don't want popups on the data

I recommend adding data as a tileset

in-class exercise

Urban Reviewer

Edgemere Urban Renewal Park

call Parks and say "where's our park?"

Edgemere Urban Renewal Park

today

today

today

today

let's map them!

we weren't the first to have this idea

Community Development Program Progress Report (1968)

Atlas of Urban Renewal (1984)

FOIL

FOILed!

thanks, volunteers!