Welcome to Advanced GIS, Lecture 10

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Advanced GIS

Class 10

April 28 and May 5: final project presentations

May 9: final projects due

there is a video of the following section

some webmaps use raster tiles

raster tiles are 256 x 256 pixel images

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

each tile is just an image on the internet

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

as you zoom in, the number of tiles quadruples

if you made tiles for all of zoom 18 you'd have billions of images

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

source

so how do you make base maps?

in theory you can make tiles on your own

many mapmakers turn to Mapbox

Mapbox provides (modified) OpenStreetMap data

there is a video of the following section

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

in-class exercise, part 1

how should we design base maps?

not too differently from offline maps

think about:

scale
hierarchy
color
symbology

hierarchy

"Important things must look important, and the most important thing should look the most important."

Understanding Different Geographies

color

Think about what the colors you are using mean to the viewer.

Use contrast to your advantage.

and consider how your data will look on top of it

using Mapbox tiles in Carto

there is a video of the following section

in-class exercise, part 2

there is a video of the following section

in-class exercise, part 3

adding your own data to a Mapbox style

there is a video of the following section

1. Upload data (such as a zipped shapefile)

2. Add the tileset to your style

in-class exercise, part 4

Mapbox isn't free

source

but it has a pretty generous free level

source

by default, Glitch refreshes every time you press a key, which adds another map view

source

Advanced GIS

dates to remember

April 28 and May 5: final project presentations

May 9: final projects due

making base maps

there is a video of the following section

some webmaps use raster tiles

raster tiles are 256 x 256 pixel images

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

each tile is just an image on the internet

as you zoom in, the number of tiles quadruples

if you made tiles for all of zoom 18 you'd have billions of images

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

so how do you make base maps?

it depends!

in theory you can make tiles on your own

many mapmakers turn to Mapbox

Mapbox provides (modified) OpenStreetMap data

creating styles

there is a video of the following section

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, part 1

how should we design base maps?

not too differently from offline maps

think about:

scale

hierarchy

color

symbology

and consider how your data will look on top of it

using Mapbox tiles in Carto

there is a video of the following section

in-class exercise, part 2

there is a video of the following section

in-class exercise, part 3

adding your own data to a Mapbox style

there is a video of the following section

in-class exercise, part 4

Mapbox isn't free

but it has a pretty generous free level

by default, Glitch refreshes every time you press a key, which adds another map view

you might not want to use Mapbox tiles when coding

or turn off automatic refreshing in Glitch