Wednesday, May 24, 2017

Urban Picture

Sunday, May 21, 2017

The impressive expansion of subway systems in China

I have posted in the past a GIF that compares the expansion of the subway systems of Rio and Shanghai between 1979 and 2014. This is a bit embarrassing for Rio, for sure, but let's be honest. Pretty much any developing county and even the USA in their efforts to develop mass transport infrastructure pales in comparison to China. Needless to say that massive expansion of infrastructure like this usually comes at high social and environmental costs that should not be neglected.

Peter Dovak (twitter) has created a new GIF that shows the expansion of subway systems in China between 1990 and 2020, giving a glimpse of the Chinese urban powerhouse. Peter has other great projects you might want to check out, including the Mini Metro Maps of the world.

ps. I saw this on the Transportation Planning and Analysis Facebook group, via Gonçalo Correia

Saturday, May 13, 2017

Time-lapse: night-flight over Europe

Great shot, by Thomas Pesquet.

Wednesday, May 10, 2017

Message of the Day

Dedicated to a dear friend, Claudia Comberti. From London to the Amazon forest.

Friday, May 5, 2017

Changing relation between wealth and left-wing vote: Piketty's guess on the French elections

I don't usually post about politics in the blog, but I had the chance to attend Thomas Piketty's presentation at the Marshall Lectures over the last two days and he dedicated a few minutes of his speech to talk about the 2017 French elections happening this weekend. 

He presented these two slides, where he shows the changing relationship between wealth + education and left-wing vote in France. The slides show what is Piketty's guess on what is going to happen in the French elections.  Hi guess are the red lines in both charts, suggesting that Macron will win the election. I think I'll just leave this here, for the record.

update after the elections: so, apparently, Piketty was correct.

photos: by Rafael H M Pereira

Thursday, May 4, 2017

Urban Picture

Street Chalking Games, New York city 1950

credit: ?, via MicropolisNYC

Wednesday, April 26, 2017

Map of Population Density Lines in R

If you are familiar with this famous Joy Division cover, you might remember that last year we shared a link that shows you how to reproduce the cover using R ggplot2. If you are a big fan of Joy Division and R, you should know that there is an R package just for that (by @mikefc).

About three years ago in 2014, James Cheshire created the Population Lines Print, a stylized map using lines to show population density in the world. It uses roughly the same data visualization style used in the Joy Division cover. 

credit: James Cheshire

How can you create a nice-looking map like this? Ask no more. James has recently shared the R script and a bit of the history behind his mapHenrik Lindberg has also generously written a gist with a simple and reproducible code to create a map with the same style showing the distribution of the population density in Europe, using R and ggplot2.

and you get this:

credit: Henrik Lindberg

UPDATE: Carson Sievert‏ shows how you can add two (2!) more lines of code to make this map interactive.

Tuesday, April 25, 2017

An unorthodox approach to spatial clustering

I left a question on gis.stackexchange about an unorthodox approach to spatial clustering that came to my mind a couple of days ago. I would be glad to hear if you have any thoughts on this. If you have any comments/answers, this time I'll ask you to write them on the gis.stackexchange website.

Monday, April 24, 2017

There is a boom in bicycle research

Although we don't know how the 'bicycle literature' has been growing relative to all publications in transport/mobility, there is a good sign there is boom in bicycle research! The method used by Jennifer to identify the publications is not supper systematic but it's insightful anyway. Jennifer's blog post is a quick and interesting read.

credit: Jennifer Dill

Thursday, April 20, 2017

Quote of the day: programming

Monday, April 10, 2017

A glimpse into the future of autonomous vehicles

Cesar Hidalgo (Twitter) has shared this mesmerizing video by People's Daily, China. It shows hundreds of autonomous robots sorting parcels in a warehouse of a Chinese delivery company.

It makes you think about many things related the technology density of the Chinese economy and the coming changes in the labor market of China and beyond. The obvious thought that occurred to me, though, is how these warehouses can be thought as a super simplified beta-version of integrated systems of autonomous vehicles we might see in cities in 100 years form now... maybe 50.

Wednesday, April 5, 2017

Two new libraries for working with Spatial data in R

A quick heads up for those interested in using R for spatial analysis and mapping data. There are two relatively new libraries you might want to check out:

  • The first one is the ggspatial library, created by Dewey Dunnington. ggspatial is a great package that makes it super simple to create maps using ggplot. It uses a single geom_spatial() for all types of spatial objects (polygons, lines, dots, etc.) and it dispenses the use fortify(), making things much faster.

  • Another library some of you might find useful is sf (as in simple features), created by Edzer Pebesma. This library makes it much faster to conduct several spatial operations, like reading/writing data, intersecting spatial objects, computing shortest distance matrices etc. The sf library is integrated with ggplot2 for creating maps with geom_sf() and it also makes it easy to connect to spatial data bases. This promises to be a real game changer for spatial analysis in R.

Monday, April 3, 2017

Saturday, April 1, 2017

Google Self-Driving Bike

This is from last year, but we can always use it on April 1st :)

Wednesday, March 29, 2017

On my way to Boston

Hi all. I'm flying to Boston in the next few days to participate at the AAG conference.

I'm very excited about this because I'll participate in a panel with Susan Fainstein and others. In the panel, I'll be talking about transportation equity and accessibility in the just city. My talk will be based on the 1st paper of my thesis and some future research questions on the topic.

I will also be at the session 3650 presenting the preliminary results of the 2nd paper of my thesis, where I analyze the distributional impacts of the transport legacy of recent mega-events in Rio de Janeiro (Brazil) in terms of their impacts in inequalities in access to opportunities. The paper combines population census data with geolocated time-tables in GTFS format in order to conduct a before-and-after comparison of Rio's public transport system between 2014 and 2017. The paper examines how the newly implemented transport investments have reconfigured the catchment areas of the Olympic sports venues and of healthcare facilities by public transport and walking, looking specifically at how the population composition within those areas has changed in terms of income categories.

The other papers of my PhD will focus on inequalities in accessibility to employment and educational opportunities, adding some new elements regarding methods and theoretical discussions. More info to come as I make progress on the research.

ps. In case you're in Boston next week and would like grab a  coffee  beer, drop me line or a tweet.

Saturday, March 25, 2017

Creating an animated world map of life expectancy changes from 1950 to 2100 in R

I've created this map after a couple of hours  procrastinating  testing the gganimate package in R, which makes it ridiculously simple to create this type animation in .gif or .mp4 format.

The map shows how the life expectancy of each country has changed from 1950 to 2015 and how it is expected to increase up to 2100. It looks better in full screen, but it's still a bit clunky.

I've also created a gist that shows how you can create this map yourself:

Thursday, March 23, 2017

cfp: special issue on informality in urban transport

Heads up. The Journal of Transport Geography has opened a call for papers for a special issue on "Concepts and methods on informality in urban transport across world regions".

Focus of the Special Issue:
The special issue intends to close the gap. Building on a set of original papers, it seeks to establish an account of the state-of-the-art of which concepts and methods are applied for what topics/aspects of informality in urban transport, an in-depth review of selected specific methods and their application in the field and the identification of their strengths and limitations, and the identification of lessons and directions for future research on the subject. The Symposium positions a set of overarching questions:
  • How and how well do existing concepts and methods capture the phenomenon of informality in urban transport? What are they missing out? What is the promise of new /emerging technology in data gathering? What can be won by combining methods?
  • What are the strengths and the limitations of approaches in specific case study contexts but also across cases and contexts?
  • How can case study and experiential-based methodologies inform network-scale analyses in more conventional transport geography?
  • What methods help to transfer knowledge from the research community across to policy making?

I saw this info on the new twitter account of the International Network for Transport and Accessibility in Low Income Communities, a research group recently created by Karen Lucas. You might wanna follow them.

Wednesday, March 22, 2017

Humans of Simulated New York: comprehensive ABM model of city life

Here is a very interesting project that aims towards building agent based models to simulate cities and the impacts of policies on them. The project is available on GitHub. Kudos to the authors, who are all on Twitter btw Francis TsengFei Liu and Bernardo Furtado.

Tseng, F., Liu, F., & Furtado, B. A. (2017). Humans of Simulated New York (HOSNY): an exploratory comprehensive model of city life. arXiv preprint arXiv:1703.05240.

The model presented in this paper experiments with a comprehensive simulant agent in order to provide an exploratory platform in which simulation modelers may try alternative scenarios and participation in policy decision-making. The framework is built in a computationally distributed online format in which users can join in and visually explore the results. Modeled activity involves daily routine errands, such as shopping, visiting the doctor or engaging in the labor market. Further, agents make everyday decisions based on individual behavioral attributes and minimal requirements, according to social and contagion networks. Fully developed firms and governments are also included in the model allowing for taxes collection, production decisions, bankruptcy and change in ownership. The contributions to the literature are multifold. They include (a) a comprehensive model with detailing of the agents and firms' activities and processes and original use of simultaneously (b) reinforcement learning for firm pricing and demand allocation; (c) social contagion for disease spreading and social network for hiring opportunities; and (d) Bayesian networks for demographic-like generation of agents. All of that within a (e) visually rich environment and multiple use of databases. Hence, the model provides a comprehensive framework from where interactions among citizens, firms and governments can be easily explored allowing for learning and visualization of policies and scenarios.

credit: Francis Tseng

Sunday, March 19, 2017

Quote of the day: the idea of community

A passage of the book "The Just City", where Susan Fainstein quotes D. Harvey to draw attention to how the idea of "Community" is a double-edged value. At the same time a community provides its members with social support, it is also exclusionary.

" 'Community' has ever been one of the key sites of social control and surveillance, bordering on overt social repression. Well-founded communities often exclude, define themselves against others, erect all sorts of keep-out signs (if not tangible walls) .... As a consequence, community has often been a barrier to rather than facilitator of progressive social change, and much of the populist migration out of villages (both rural and urban) arose precisely because they were oppressive to the human spirit and otiose as a form of sociopolitical organization". (David Harvey, 1997)

Friday, March 17, 2017

Chart of the Day: the gender gap in science

Elsevier has recently published the report "Gender in the Global Research Landscape", in which they analyze 'research performance through a gender lens across 20 years, 12 geographies, and 27 subject areas'. The team at The Economist wrote a short summary of the report, showing this chart. 

Thanks Claudio Ferraz for the pointer on twitter.

Thursday, March 16, 2017

Demographic fact of the day

Nigeria is the fastest growing countries in the world. The population of Nigeria will nearly double in the next 30 years.

Very interesting episode of BBC's Economic Tectonics on how economic power will shift as the world’s population changes, by Ruth Alexander.

Wednesday, March 15, 2017

Creative Process

This comes in cycles and I'm currently at stage #2, again.

Monday, March 13, 2017

The world's tallest and most densely populated slums

A short video about Tower of David, possibly the tallest slum today, located in Caracas, Venezuelza. (Thanks Telmo Ribeiro and Lucas Mation for the pointer)

And a short video about Kowloon Walled City of Hong Kong, which was of the most densely populated slums in the world until being demolished in 1994.

Thursday, March 2, 2017

Special issue on Human migration and refugees

Nature has a new special issue on migration and refugees (via Nicolsa Perra).

The United Nations has declared that the number of displaced people has surged to unprecedented numbers. But a close examination of data reveals that current flows are just as high as in they were in the 1990s. Because it is difficult to track refugees, official data and statistics must be handled with care, and yet misleading reports are creating unjustified fears about refugees.

source: UNHCR via Nature

Wednesday, March 1, 2017

Alternative Facts

via Daniel Pessini Sobreira on Facebook.

Tuesday, February 28, 2017

Quote of the day: Plans

For when you start your PhD: 
"Plans are worthless, but planning is everything" Eisenhower

When you get close to the end of your PhD:
“Everybody has a plan until they get punched in the face.” Mike Tyson

I could say Mike Tyson is my academic hero right now :)

Monday, February 20, 2017

Analyzing transport accessibility in Sweden, step 1

I've spent a few hours yesterday testing OpenTripPlanner to model transport accessibility by different transport modes in Swedish major metro areas, Stockholm, Gothenburg and Malmo. This is part of a project where I'm collaborating with colleagues from Lund University and K2 - The Swedish Knowledge Centre for Public Transport. Jean Ryan, Anders Wretstrand and I are engaging with the human capabilities approach and conducting a comparative study of transport accessibility of elderly people. Stay tuned.

Latter this year, I will post a detailed step-by-step + code of how I've been conducting accessibility analysis for my PhD and other projects. In short, I estimate travel-time matrices using OpenTripPlanner (I explain how to do this on GitHub). I then process the travel-time matrices with other spatial data in R, mainly using the super fast data.table library and make the plots using ggplot2 and ggmap.

These figures show just some preliminary tests for accessibility by bicycle + public transport. They values are meaningless here but the maps look good, right?

click on the image to enlarge it

Here are a couple of our recent publications related to this topic:

Sunday, February 19, 2017

Monday, February 13, 2017

On the specification of spatial models

One of best sentences I've read in an academic paper in years:
"Without divine intervention it is generally difficult to know with certainty which (if either) of the two above cases are true"
This is from Fotheringham et al (1998) on the specification of spatial models. I find this quite amusing but I must say this is one of the most well written and accessible articles on spatial econometric models I've come across so far. It's not by chance this paper has become a great reference on the topic with more than 500 citations.

I've only started reading more about spatial models recently. Here are four papers I would recommend to get started on the topic.
  • Anselin, L. (2002). Under the hood Issues in the specification and interpretation of spatial regression models. Agricultural Economics, 27(3), 247–267.
  • Fotheringham, A. S., Charlton, M. E., & Brunsdon, C. (1998). Geographically Weighted Regression: A Natural Evolution of the Expansion Method for Spatial Data Analysis. Environment and Planning A, 30(11), 1905–1927.
  • Florax, R. J. G. M., Folmer, H., & Rey, S. J. (2003). Specification searches in spatial econometrics: the relevance of Hendry’s methodology. Regional Science and Urban Economics, 33(5), 557–579. [thanks Leo Monasterio for the recommendation]
  • Páez, A., & Scott, D. M. (2005). Spatial statistics for urban analysis: A review of techniques with examples. GeoJournal, 61(1), 53–67.

This paper is particularly relevant to problem raised in the quote above:

  • Gibbons, S., & Overman, H. G. (2012). Mostly Pointless Spatial Econometrics?*. Journal of Regional Science, 52(2), 172–191

I just happened to like this plot.

Wednesday, February 8, 2017

Quote of the Day

"My interest is not data, it's the world. And part of world development you can see in numbers. Others, like human rights, empowerment of women, it's very difficult to measure in numbers." 
(Hans Rosling in an interview in 2013)

Thanks Sunniva Sandbukt for bringing this quote to my attention.

Tuesday, February 7, 2017

Hans Rosling passed away today

"We are extremely sad to announce that Professor Hans Rosling died this morning. Hans suffered from a pancreatic cancer which was diagnosed one year ago. He passed away early Tuesday morning, February 7, 2017, surrounded by his family in Uppsala, Sweden."
This information comes from Gapminder, which Hans was one the founders in 2006.

Hans was incredibly knowledgeable of social and economic dimensions behind population and health issues. He was also and incredible speaker who gave a great contribution to the public understanding of population studies (his Ignorance Project is one of my favorites). Also thanks to the great relevance of the Gapminder project, he became internationally famous because of his TED talks, to the point he became know as the “Mick Jagger" of TED.

I've included below a few links to some of our previous posts on Hans Rosling's work, but he has has many more incredible videos, material out there on the web that will keep a beautiful memory of Hans and his work.

My sentiments to the Rosling's family and close friends.

Some of our posts on Hans Rosling's work.

Monday, February 6, 2017

How much of the world is covered by cities? not much

Vinicius Netto asked this question a few days ago. Here is the answer I've found based on a paper by Seto and colleagues.

Friday, February 3, 2017

Intro to Spatial Data Science

Seven recorded lectures on Spatial Data Science by Luc Anselin at the University of Chicago (October 2016). It might be of interest to some readers of this blog as well. 

By the way, the Center for Spatial Data Science is also on Twitter.

Thursday, February 2, 2017

Urban Picture

Flatland: a beautiful project by the photographer and digital artist Aydın Büyüktaş, who creates Inception-like photos of Turkish Cityscapes (via Colossal).

Saturday, January 28, 2017

A glance of the street art murals of Sao Paulo

The video was made by Kico Santos and his team at Cinema de Rua. The current city policy towards the city's graffiti has been a complete joke, by the way. Thanks Vinicius Netto (Twitter) for the pointer.

Monday, January 23, 2017

How writing to your PhD supervisor feels

In case my supervisor sees this, this is meant to be a joke of bad taste.

An open dataset with 6,000 years of global urbanization

Patrick Gerland points to a new paper/open dataset that provides the first spatially explicit archive of the location and size of urban population settlements over the last 6,000 years. We have previously posted in this blog about the fantastic work of Karen Seto and her group at Yale at the Seto lab on Urbanization and Global Change (here and here). This one adds up to a great and continuous effort on improving spatially explicit models of population growth and urbanization, with important contributions to historical and prospective research.

Reba, M., Reitsma, F., & Seto, K. C. (2016). Spatializing 6,000 years of global urbanization from 3700 BC to AD 2000. Scientific data, 3.

How were cities distributed globally in the past? How many people lived in these cities? How did cities influence their local and regional environments? In order to understand the current era of urbanization, we must understand long-term historical urbanization trends and patterns. However, to date there is no comprehensive record of spatially explicit, historic, city-level population data at the global scale. Here, we developed the first spatially explicit dataset of urban settlements from 3700 BC to AD 2000, by digitizing, transcribing, and geocoding historical, archaeological, and census-based urban population data previously published in tabular form by Chandler and Modelski. The dataset creation process also required data cleaning and harmonization procedures to make the data internally consistent. Additionally, we created a reliability ranking for each geocoded location to assess the geographic uncertainty of each data point. The dataset provides the first spatially explicit archive of the location and size of urban populations over the last 6,000 years and can contribute to an improved understanding of contemporary and historical urbanization trends.

credit: Reba, Reitsma and Seto

Friday, January 20, 2017

off-topic: Inauguration Day


credit: unknown

Tuesday, January 17, 2017

Extreme poverty worldwide has more than halved since 1990

The percentage of people living in extreme poverty around the world has fallen by more than half over the past three decades (via Dina Pomeranz). According to a recent study, a significant majority of respondents from several countries are unaware of this achievement. I wasn't aware either!

On a side note, Oxfam is on the news again with their report on wealth inequality. Oxfam's method is quite questionable and there are lots of articles out on the web criticizing it. Last year, Tim Harford addressed this issue in his podcast More or Less (brilliant podcast, btw). You can listen to this explanation in this 10 minute-audio.

ps. the shortcomings of Oxfam's estimates do not imply we face low levels of global inequality, but they do distort the numbers in a way that attracts lots of headlines.

Sunday, January 15, 2017

Music for the weekend

Good soundtrack for coding and data analysis.

Saturday, January 14, 2017

Who uses active transportation in Brazil?

The proportion of workers who cycle or walk to work in Brazil is approximately 33%, a similar proportion found in France (34.9%) and Holland (37.9%). Yet, cycling and walking as modes of transport are strongly associated with lower income groups in Brazil. Depending on the metropolitan area, the use of active transportation is two to five times more frequent among low-income individuals than among high-income individuals.

In a recent paper, some colleagues and I discuss the socioeconomic and regional differences in active transportation in Brazil using nationally representative data from 2008 (here is the paper in Portuguese). We've been working on a new paper that updates these data and analyzes the relationship between active transport and health outcomes in the country.

click on the image to enlarge it

Wednesday, January 11, 2017

Two open positions at TSU Oxford

Heads ups: there are currently two open positions at the Transport Studies Unit (TSU) at Oxford University:

Sunday, January 8, 2017

PhD status report

My  procrastination  blogging activity has been lower than the usual for PhD reasons. Bear with me :)

Monday, January 2, 2017

Urban Picture

Cinematic Photographs of Tokyo, by Masashi Wakuiby (via Christopher Jobson - Colossal)

credit: Masashi Wakuiby