Saturday, July 30, 2016

Streetcars of San Francisco

For some reason I've always imagined that there were a lot more streetcar lines in San Francisco. The good news is that there are actually more routes now than in 1960. However the present coverage is not a patch on the number of streetcar routes that existed in the city back in 1940.

Where the Streetcars Used to Go is a lovely interactive map which allows you to view the streetcar transit network as it existed in 1940 & 1960 and as it exists today. Streetcar fans will be delighted to learn that the map also allows you to view vintage photos of streetcars in San Francisco.

You can actually browse through these wonderful photos of San Francisco's historical streetcars by the different streetcar routes. If you click on a streetcar route on the map the photos, running along the bottom of the map, are filtered to only show photos taken along the chosen line. The name of the selected route is also displayed on the map alongside the dates when the route was operational.

Mapping Child Poverty in London

Steven Feldman of KnowWhere has mapped the changes to child poverty rates in London between 2008 and 2013. The results suggest that child poverty has decreased in most London wards over this period. As Steven mentions in his commentary on the data this is good news - and rather surprising considering the UK government's austerity measures.

Child Poverty in London includes a number of maps of the data. These include three static maps created with QGIS (showing child poverty in 2008, 2013 and the changes in child poverty 2008-2013), an OpenLayers map (showing the changes in child poverty rates), and a Leaflet map which allows you to view the 2008 & 2013 child poverty rates and also view the changes in child poverty 2008-2013.

The maps are accompanied by Steven's commentary on the child poverty data and on the process of creating the maps with PostGIS, QGIS, the QGIS2Web plugin and Leaflet.js.

Friday, July 29, 2016

Whose Being Evicted in San Francisco?

The Anti-Eviction Project has created a lot of interesting maps around the issue of housing in San Francisco. For their latest map the Anti-Eviction Project has teamed up with Carto to visualize eviction rates in the city by neighborhood, demographic segment and median rent.

The Evictions by Demographic Segment map shows a choropleth view of the number of evictions in San Francisco by area. However, by using census data from the American Community Survey, the map can also show you demographic information about each neighborhood. Using the two sets of data together it is possible to get a good idea of where people are being evicted and why.

Using the filter controls in the map sidebar you can view the number of evictions by demographic segment. The most evictions in 2015 took place in areas of 'high rise, dense urbanites'. You can also use the median rent filter to view evictions by rental cost. This shows that there is a higher rate of evictions where rents are high. In other words in San Francisco there is a strong trend by landlords to evict people in areas with wealthy residents and high rental returns.

Which are the Squarest & Roundest Countries?

Sierra Leone is the roundest country in the world. The most rectangular country is Egypt.

Forget the battle between Clinton & Trump. The biggest online debate over the last few weeks has been over which are the most rectangular and round countries.

The controversy started earlier this month when David Barry posted his research into The Rectangularness of Countries. Barry used the shapefile data from Natural Earth to discover which country's boundaries were the most rectangular using a 'simple algorithm'. His results suggest that Egypt is the most rectangular country, closely followed by the Vatican.

Gonzalo Ciruelos was inspired enough by Barry's work to attempt to discover the most round countries in the world. In What is the Roundest Country? Ciruelos also used Natural Earth's shapefile data. He found that Sierra Leone is the roundest country. With Nauru coming in a close second.

Now all we need to know is 'Which is the most triangular country in the world?'

Thursday, July 28, 2016

Election Chartograms

The major winner in the last UK general election was the tiled grid map. My bet for this year's U.S. election is the 'chartogram'.

For example this week the Wall Street Journal has created an historical U.S. election map which represents each state as a bar chart showing the state winners in previous elections. A Field Guide to Red and Blue America is similar to a traditional tiled grid map, except dynamic bar charts have been used instead of colored grids. At the risk of butchering the English language I'm going to refer to this type of grid map as a 'chartogram'.

This isn't the first time that individual grids have been used to visualize historical election data. For example, after the Scottish Election in May, The Guardian used Sankey diagrams in a tiled grid map of Scotland to show the historical percentage of votes by each political party over previous elections in each electoral district.

Esri has also been experimenting with using different types of charts and graphs within individual tiled map grids to visualize U.S. election history data. US Election History is an interactive tiled grid map which visualizes the historical voting pattern of each state in a number of different ways.

My favorite view in this tiled grid map is the Waffle Grid, which presents the historical election data in each state with a series of small colored squares. Each square is colored red or blue to show how the state voted in previous US elections.

The Wall Street Journal is showing similar historical election data, only it is using bar charts rather than 'waffle grids'.

I have a feeling that we might be seeing quite a few of these types of tiled grid maps or chartograms in the next six months. If you want to create an interactive version of this type of map then it might be a good idea to start honing your d3.js skills and practice adding an SVG overlay pane to Leaflet maps.

The Impact of the Olympics on Rio

Esri has produced a great interactive presentation exploring Rio de Janeiro's preparations for the 2016 Olympic Games. Ready or Not, Let the Games Begins examines the impact on Rio, both positive and negative, of the infrastructure developments being made for the games and how these changes are affecting the city and its citizens.

The interactive is divided into five main sections looking at; the impact of construction projects, the displaced people living in the favelas, the spread of the Zika virus, pollution and security issues in the city.

Because the presentation is created by Esri many of these issues are, of course, illustrated with accompanying interactive maps. The interactive uses a story map format, so that as you scroll through the presentation the maps automatically update to illustrate the accompanying text. I particularly like how Map Swipe is used in some of the maps to automatically reveal and compare different base map layers.

Wednesday, July 27, 2016

The Living Dead of Andorra

After looking at average heights around the world earlier today it seems like a good idea to look at the average life expectancy of different countries across the globe. Unfortunately this 3DFx Widget - Life Expectancy map is as bad as Le Pais' average height map is good.

It's hardly ever a good idea to try and visualize data on a 3d globe with vertical towers. It is in fact a really bad idea when the difference between the different values you want to show is very small. It is an even worse idea to then perpetually bounce your vertical bars up and down.

I defy anyone to accurately read the average life expectancy of a country on this 3d globe using the vertical towers on the map. I find it next to impossible to even judge which countries have taller towers than other countries.

Luckily this average life expectancy map does have a little table running along the bottom of the map showing the average life expectancy of countries in order (with Hong Kong having the highest). If I was 3DFx I would get rid of the 3d globe and just display this list.

I feel really sorry for anyone living in the last 16 countries in this list - including the Isle of Man, San Marino and Andorra. Apparently if you are from any of these countries you have a life expectancy of 0 and are therefore presumably dead.

BTW - it also took me an age to work out how to view the data on top of the 3d globe. You appear to need to click on the little globe icon in the top right-hand corner of the globe before the data is displayed.

Hat-tip: Google Street View World

NYC: Travel Time & Jobs

Eighteen of the top Twenty neighborhoods for job access in New York City are in Manhattan. If you live in Manhattan there are an average of 4,128,263 jobs accessible within one hour by public transit.

You can use the Rudin Center's NYC Neighborhoods: Mobility and Economic Opportunity interactive map to view the number of jobs available within one hour of travel in each of NYC's neighborhoods. If you select a neighborhood on the map you can view a basic isochrone layer showing the neighborhoods in range of 30, 45 and 60 minutes of travel on public transit.

You can also view details on the number of jobs accessible within 60 minutes of travel and the types of job (by industry). The information panel includes other details about the neighborhood, such as the population total, median income and the unemployment rate of the selected neighborhood.

The map reveals that neighborhoods with good transit links, such as those in Manhattan, are most likely to have the best access to jobs. Conversely neighborhoods with limited transit links (neighborhoods ranked 60-119 on the map) have higher unemployment rates than those neighborhoods with the best transit links.

You can read more about the findings of the mapped data in this Rudin Center report (pdf).

Height Mapping

El Pais has mapped out the average heights of men and women in countries around the world. The Average Height for Countries map reveals the average heights of 30 year old men and women across the globe. It also shows how much the average height of men and women has increased in each country over the last 100 years.

The map includes four different layers. which you can view by selecting the four buttons at the top of the map. The four layers show: the average height of men in 2014, the growth in average male height compared to 100 years ago, the average height of women in 2014 and the growth in average female height compared to 100 years ago.

According to the El Pais map the tallest men and women are in European countries. Women in South Korea have shown the biggest increase in average height over the last 100 years. For men the biggest increase in average height over the last 100 years has been in Iran.

Tuesday, July 26, 2016

Extract a Map

MapXtract is a really neat tool to style a map and then download it as a png, svg or GeoJSON. The MapExtract editor uses OpenStreetMap data so should work for any location in the world.

To use MapXtract you just need to pan and zoom the map to the location that you want for a map. A location search function is missing from MapXtract. This means that you need to find the location that you require for yourself on the map.

Once you have panned the map to the required location you can style the colors of map features using an easy to use color picker tool. MapXtract allows you to color roads, water features, natural features, buildings, the background layer and an admin layer.

Once you've picked your location and chosen your map colors you're done.  All you need to do now is choose to download your map as a png, svg of GeoJson file.