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Posts by Rafael H. M. Pereira 🚡 Urban Demographics

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SENIOR DATA ANALYST & INTEGRATOR (Data Operations) SENIOR DATA ANALYST & INTEGRATOR (Data Operations)

I'm #hiring for #DataOperations to build and maintain transportation data pipelines and the infrastructure they depend on. We use #Airflow & #Python in #AWS and #RHEL to Extract, Validate, Load & Transform our data in a #PostgreSQL database.
Deadline April 27th.
jobs.toronto.ca/job-invite/6...

1 week ago 2 1 1 0
Streamgraph titled "Name Waves: the Ebb and Flow of American Baby Names," displaying the popularity of the top 10 baby names per sex in the USA from 1950 to 2022, sourced from the US Social Security Administration. Stream width reflects total births. Color encodes peak era: warm tones (yellow, orange, red) for early-peak names and cool tones (pink, purple, blue, teal, green) for recent-peak names.

The chart is split into two sections stacked vertically. The upper section, labeled "Girls" in bold teal, shows a wide stream that peaks broadly around the 1980s–1990s before narrowing toward 2022. Names labeled within the streams include Linda, Mary, Susan, Lisa (warm tones, prominent in the 1950s–1960s), Patricia and Jennifer (mid-era, orange to pink), and Sarah, Ashley, Jessica, Elizabeth (cooler tones, prominent from the 1980s onward). The lower section, labeled "Boys," shows a similarly shaped stream widest in the 1950s–1960s and tapering toward 2022. Names labeled include James, John, Robert, William, David, Michael (warm yellow-green tones, dominant in the 1950s–1970s), and Joseph, Matthew, Christopher, Daniel (cooler teal and purple tones, peaking in the 1980s–1990s). Credit text reads: "Data: US Social Security Administration via {babynames} · #30DayChartChallenge 2026 · Day 12 · FlowingData · Ilya Kashnitsky @ikashnitsky.phd."

Streamgraph titled "Name Waves: the Ebb and Flow of American Baby Names," displaying the popularity of the top 10 baby names per sex in the USA from 1950 to 2022, sourced from the US Social Security Administration. Stream width reflects total births. Color encodes peak era: warm tones (yellow, orange, red) for early-peak names and cool tones (pink, purple, blue, teal, green) for recent-peak names. The chart is split into two sections stacked vertically. The upper section, labeled "Girls" in bold teal, shows a wide stream that peaks broadly around the 1980s–1990s before narrowing toward 2022. Names labeled within the streams include Linda, Mary, Susan, Lisa (warm tones, prominent in the 1950s–1960s), Patricia and Jennifer (mid-era, orange to pink), and Sarah, Ashley, Jessica, Elizabeth (cooler tones, prominent from the 1980s onward). The lower section, labeled "Boys," shows a similarly shaped stream widest in the 1950s–1960s and tapering toward 2022. Names labeled include James, John, Robert, William, David, Michael (warm yellow-green tones, dominant in the 1950s–1970s), and Joseph, Matthew, Christopher, Daniel (cooler teal and purple tones, peaking in the 1980s–1990s). Credit text reads: "Data: US Social Security Administration via {babynames} · #30DayChartChallenge 2026 · Day 12 · FlowingData · Ilya Kashnitsky @ikashnitsky.phd."

DAY 12 -- Flowing Data 🌊 #30DayChartChallenge
Explorations of the US names are always fun. Here we look at the most popular names by sex and distinguish them by timing of their peak popularity 🗻
🔗 #rstats code: github.com/ikashnitsky/...
🧙‍♂️ pplx chat: www.perplexity.ai/search/day-1...

1 week ago 14 4 2 0
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Facility and route optimization on road network graphs can solve countless problems across many industries.

However, these solvers often require expensive software to set up and run them, or expensive, rate-limited travel-time matrix APIs.

The spopt-r R package offers a solution.

1 week ago 32 6 1 1
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The Huff model is the classic algorithm in retail spatial analysis - and you can now use it in R.

Predict:
- Which store a customer is likely to visit
- Sales potential per location
- How new stores reshape the competitive landscape

Learn more: walker-data.com/spop...

1 week ago 25 4 0 0

I've been waiting to read something like this for a long time. Thanks, @transportist.org !

1 week ago 3 0 1 0
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Diagonal panning video from a very detailed shaded map of Szczecin, Poland. The full map is 20000 x 20000 pixels with 0.5 m resolution and is available at https://shadedmaps.github.io Data source: https://www.geoportal.gov.pl [Head Office of Geodesy and Cartogr...

2 weeks ago 7 4 0 0

Não dá pra extrapolar nossos resultados não, a gente fala isso no artigo. Mas outros estudo no mundo olhando para a populacao em idade ativa chegam na mesma conclusao

2 weeks ago 3 0 1 0
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New in the R mapgl package: static maps!

I developed mapgl to bring my favorite interactive mapping libraries to R. But - interactive maps are by definition hard to share in non-interactive formats.

I'm rolling out a couple new functions I'm already finding useful:

3 weeks ago 20 3 1 0
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GitHub - ipeaGIT/enderecobr: Pacote de R para padronizar endereços brasileiros Pacote de R para padronizar endereços brasileiros. Contribute to ipeaGIT/enderecobr development by creating an account on GitHub.

Wonderful! Thanks! We're using Rust in this package but I'm not sure we're following good practices github.com/ipeaGIT/ende... Any feedback here would be super welcome !

3 weeks ago 2 0 0 0

Any chance the slides will be shared online ?

3 weeks ago 2 0 1 0

Come to @cascadiarevolting.bsky.social and take my Intro to Rust + Extendr workshop ORRRR contribute to base R your call!

I'll only be offended if you don't come! /s

#rstats

3 weeks ago 7 4 1 0

Paris has just elected another bike-friendly mayor!
After Anne Hidalgo transformed the city, her PS-colleague Emmanuel Grégoire takes over, beating former right-wing minister Rachida Dati by a large margin.

4 weeks ago 113 22 3 0
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Which brings me to my research! What we show in this paper is that AI’s ability to produce expert-looking content at zero cost *raises* the demand for experts who can help you tell apart real from fake. 7/
filipecampante.org/wp-content/u...

2 months ago 78 13 1 2
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This is why I'm so excited about my new R/Python package, {freestiler}.

I connect to a 146M row @duckdb.org database; generate vector tiles for 2.8 million jobs in CO from a query; serve the tiles and visualize on a @maplibre.org map.

All in seconds!

Get started: walker-data.com/freestiler

1 month ago 35 7 1 0
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Coding After Coders: The End of Computer Programming as We Know It

Recomendado por várias pessoas, esse texto na NYTMag sobre a nova era dos agentes de IA é muito bom.

Ele (e algumas conversas entre ddjs) me ajudou a pensar sobre o papel dos agentes de IA numa pesquisa acadêmica de humanidades digitais. (reflexões pessoais abaixo)

www.nytimes.com/2026/03/12/m...

1 month ago 5 2 1 0
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LinkedIn This link will take you to a page that’s not on LinkedIn

- Measuring exposure to extreme heat in public transit
Paper: www.sciencedirect.com/science/arti...
🔓PDF: www.urbandemographics.org/publication/...

- Estimating public transport emissions from GTFS data
Paper: www.sciencedirect.com/science/arti...
🔓PDF: www.urbandemographics.org/publication/...

1 month ago 0 2 1 0
LinkedIn This link will take you to a page that’s not on LinkedIn

My presentation as well as the entire conference is available on Youtube. Here's the link to the recording
www.youtube.com/watch?v=_v19... + and papers👇

1 month ago 1 0 1 0

I had the opportunity to present two recent studies. One paper looking at the exposure to extreme heat of transit users; and another paper where we proposed an open-source computational model to measure transit emissions from GTFS data +

1 month ago 0 0 1 0
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A couple of weeks ago, @harvardsalata.bsky.social convened a conference on Urban Mobility and Climate Change, bringing together leading experts addressing a wide range of challenges at the intersection of transportation and climate change +

1 month ago 7 2 1 0
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We revised our Skyscraper Revolution paper github.com/Ahlfeldt/DPs...
Added indirect inference to estimate the QoL effect of density by matching causal reduced-form estimates in the model => more realistic counterfactuals. Quick read @voxeu.org: cepr.org/voxeu/column... @bsoeberlin.bsky.social

1 month ago 21 10 0 0
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New in the spopt-r #rstats package: route optimization.

Solve the classic Traveling Salesman Problem for a single driver or optimize a fleet by solving the Vehicle Routing Problem.

Written in Rust so they solve fast.

Read the vignette which covers r5r integration: walker-data.com/spop...

1 month ago 18 3 0 0

Yes, I'm starting to use duckspatial in some projects but we're planning a major update in the next few weeks, so I'd say it's not ready to use it in production yet. I'm also quite excited with sedona.db it seems the R support is not really a priority

1 month ago 0 0 0 0
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I had (kinda jokingly?) wondered if there was a Skill that helps write Skills... and there is!

From the Anthropic Skills marketplace: github.com/anthropics/s...

1 month ago 27 5 1 0
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#rstats users will be pleased to know that you can now read anything sf can piped directly into SedonaDB via GDAL's @arrow.apache.org integration. This makes the SedonaDB R package considerably more useful!

1 month ago 6 1 1 0
A dot map of Minneapolis, MN's population by race

A dot map of Minneapolis, MN's population by race

A dot map of Minneapolis, MN's population by race, created using data from the 2020 US Census.

🔵 = White, 🟢 = Black, 🟠 = Hispanic, 🔴 = Asian, 🟤 = Native American/Other, 🟣 = Multiracial

Explore the map: www.censusdots.com/race/minneapolis-mn-demo...

1 month ago 1 2 0 0
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Announcing {freestiler}: a high-performance vector tiling engine for R and Python.

Generate vector tiles for your maps directly from R/Python spatial data, @duckdb queries, and local spatial files.

Check out the docs here: walker-data.com/free...

Some highlights:

1 month ago 45 11 2 1
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The Trays, the most beautiful open office space I've seen. At the Harvard Graduate School of Design GSD

1 month ago 5 0 0 0
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We're kicking off March with two data-driven talks, from 🏙️ cities to ⚾ baseball.
𝗥𝗮𝗳𝗮𝗲𝗹 𝗛. 𝗠. 𝗣𝗲𝗿𝗲𝗶𝗿𝗮 explores spatial accessibility and equitable urban policy.
𝗦𝗰𝗼𝘁𝘁 𝗣𝗼𝘄𝗲𝗿𝘀 applies modern stats to baseball, from pitch models to MLB pickoff strategy and bat-tracking data.
tinyurl.com/mpr87m6t

1 month ago 5 2 0 1
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1 month ago 14 3 0 0
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As of 2025, this analysis of privacy policies indicates that every major AI company uses your private conversations to train their models by default. Every prompt, file, photo, personal detail: all of it feeds directly into model training. arxiv.org/pdf/2509.05382

1 month ago 15 9 3 2