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@mbostock
Last active Nov 8, 2019
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Zip Codes
license: gpl-3.0

The Census Bureau provides a 797M shapefile for national zip code tabulation areas. Simplified using TopoJSON (with -q 1e5 -s 3e-7), the resulting file is only 7.2M, a reduction of 99.1%. The distribution of zip codes is a rough proxy for population density. Part of the U.S. Atlas project.

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@mittenchops
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mittenchops commented Aug 3, 2013

I followed the reduction using topojson---but what did you use for rendering the PNG? Also, would an SVG of this size and complexity be suitable for an interactive graphic with D3, if I had to do dynamic coloration on the fly? Or is this something you'd recommend processing to non-vector format first, such as you have here?

@huertanix
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huertanix commented Oct 28, 2016

I used https://github.com/mbostock/us-atlas and ran make shp/us/zipcodes-unmerged.shp to get a shapefile for us zip code boundaries.

When I ran this to get topojson...

topojson -o zips.json -q 1e5 -s 3e-7 shp/us/zipcodes-unmerged.shp

...I got this:

<--- Last few GCs --->

6606 ms: Scavenge 1398.4 (1458.0) -> 1398.4 (1458.0) MB, 0.5 / 0 ms (+ 6.6 ms in 1 steps since last GC) [allocation failure] [incremental marking delaying mark-sweep].
7190 ms: Mark-sweep 1398.4 (1458.0) -> 1398.3 (1458.0) MB, 584.1 / 0 ms (+ 11.0 ms in 5 steps since start of marking, biggest step 6.6 ms) [last resort gc].
7772 ms: Mark-sweep 1398.3 (1458.0) -> 1398.3 (1458.0) MB, 581.7 / 0 ms [last resort gc].

<--- JS stacktrace --->

==== JS stack trace =========================================

Security context: 0x21cfaeab4629 <JS Object>
1: /* anonymous */(aka /* anonymous */) [/usr/local/lib/node_modules/topojson/node_modules/shapefile/shp.js:~92] [pc=0x1d09df473a1e] (this=0x21cfaea041b9 <undefined>,record=0x130f64716379 <an Uint8Array with map 0x6eeee4048e9>)
2: readRecord(aka readRecord) [/usr/local/lib/node_modules/topojson/node_modules/shapefile/shp.js:40] [pc=0x1d09df462fe7] (this=0x21cfaea041b9 <undefined>,error=...

FATAL ERROR: CALL_AND_RETRY_LAST Allocation failed - process out of memory
Aborted (core dumped)

Any idea what's going on?

@tabrewer
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tabrewer commented Jul 12, 2018

Do you have the topoJSON stored in a repository? I would like to use it for a visualization and need the link to the file. Thanks!

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