Revfad Blog

Tag: maps

  • California cities from CDTFA

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    David Faden
    in

    At least based on the dates listed on https://lab.data.ca.gov/dataset/california-city-boundaries-and-identifiers — still says “03/24/25” — I’m guessing the city boundaries haven’t been updated yet. For a current project, I want the best boundaries available so let’s work directly with the source pointed out by the CIO, GIS: https://gis.data.ca.gov/datasets/CDTFA::city-and-county-boundary-line-changes/explore?layer=0&location=33.924386%2C-118.008294%2C11.67. > library(sf)> d <- read_sf(“~/Downloads/City_and_County_Boundary_Line_Changes_217120214122415134.gpkg”) It turns out…

  • A hole in Los Altos

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    David Faden
    in ,

    Looking at the Census page for Los Altos, something funny caught my eye: there’s a hole in the map for Los Altos: https://data.census.gov/profile/Los_Altos_city,_California?g=160XX00US0643280 Returning to the data from https://lab.data.ca.gov/dataset/california-city-boundaries-and-identifiers, we see the same thing: > library(ggplot2)> library(sf)> cities <- read_sf(“~/Downloads/California_Cities_and_Identifiers_Blue_Version_view_-6943741225906831761.gpkg”)> losAltos <- subset(cities, CDTFA_CITY == “Los Altos”)> ggplot(losAltos) + geom_sf() What’s in that hole? >…

  • What Wittier Whittier

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    David Faden
    in

    I was really impressed to get an almost immediate reply from the CIO, GIS to my note about Whittier appearing to some extra stuff in the geometries provided here: https://lab.data.ca.gov/dataset/california-city-boundaries-and-identifiers. They pointed to the California Department of Tax and Fee Administration as the original source of the geometries, which has been updated in the meantime:…

  • California cities (continued)

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    David Faden
    in

    Let’s get back roughly to where we were with the R session from California cities, reading in a copy of the data pulled from Wikipedia. > library(dplyr)> library(fillpattern)> library(sf)> library(ggplot2)> cities <- read_sf(“~/Downloads/California_Cities_and_Identifiers_Blue_Version_view_-6943741225906831761.gpkg”)> stats <- read.csv(url(“https://raw.githubusercontent.com/fadend/ca_cities_data/refs/heads/main/ca_cities.csv”), stringsAsFactors=FALSE) Oops. There’s some disagreement on names: > setdiff(stats$city_name, cities$city_name)[1] “Angels Camp” “California City” “City of Industry”> setdiff(cities$city_name, stats$city_name)[1]…

  • California cities

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    David Faden
    in

    Here’s something fun: boundaries for cities in California: https://lab.data.ca.gov/dataset/california-city-boundaries-and-identifiers. Working with this in R: > library(sf)> cities <- read_sf(“~/Downloads/California_Cities_and_Identifiers_Blue_Version_view_-6943741225906831761.gpkg”) There are a few columns with the city names; “CENSUS_PLACE_NAME” and “CDTFA_CITY” (CA Department of Tax and Fee Administration?) agree so let’s just use “CDTFA_CITY” > sum(cities$CENSUS_PLACE_NAME != cities$CDTFA_CITY)[1] 0 It’s nice to see that there…

  • Obstetrical care in Iowa

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    David Faden
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    The third article in Kalen McCain’s excellent series on maternal healthcare in southeastern Iowa, Barriers aren’t limited to birthdays, features a map from numbered page 14 of ACCESS TO OBSTETRICAL CARE IN IOWA: A REPORT to the IOWA STATE LEGISLATURE – CALENDAR YEAR 2021 [PDF]. This got me wondering what it would take to reproduce…

  • Iowa county seats

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    David Faden
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    I got the coordinates of the county seats using the utility I previously wrote to get California county seats: The generated CSV is now available here: https://github.com/fadend/county_seat_coords/blob/main/county_seat_coords/generated/ia_usa_county_seats.csv. One complication that it doesn’t handle: Lee County has *two* county seats. A little copying pasting from the R code from the other post produced a pretty okay…

  • ArcGIS map linking

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    David Faden
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    Something I’ve found frustrating with a few different instances of ArcGIS-based maps is the lack of an easy ability to share or link to a particular location. E.g., one of the water districts shares this map: https://valleywater.maps.arcgis.com/apps/webappviewer/index.html?id=39632100ff6d48dcab9405ee080b142b. After some fruitless searching in regular search, Gemini helped get me on the right track in response to…