TopoJSON is an extension of GeoJSON that encodes topology.

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How to load big geo-data file into web application

I am building a web app where I show details in map. I load data using geojson file (190 mb). I was looking in different possibilities to show the data, here there are: Leaflet GeoJSon: it should ...
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23 views

Simplifying TopoJSON causes leak of Natural Earth in d3

I'm working with topoJSON and D3 to display Natural Earth data on a globe. Obviously, we need to simplify our geometries while still keeping borders consistent. We've created a script as based on ...
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1answer
116 views

Which plugin can draw topoJson right within Leaflet without conversion?

I already have asked how to reduce file size and increase performance for publishing spatial data on the web using Leaflet, here. A conversion to TopoJSON has reduced the file size by approximately ...
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1answer
81 views

How to convert cartesian to lat-lon with Topojson?

I've been following the "Let's Make a Map" tutorial by mbostock about converting files for use for d3.js. I have been able to get things working with files from Natural Earth, but when trying to ...
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0answers
41 views

Filtering a Topojson on server-side. Which part of topology I need?

I have a big Topojson which I want to avoid loading it at page load. Instead I would like to parse on server-side at user request, sending back chunks of this original Topojson to be ploted. So I ...
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369 views

D3 adding topojson - no data visible

Yesterday I asked what would be the best method of creating an overlay in a web map that would allow for some interactivity. Create interactive map with no server Thanks to a variety of people who ...
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3answers
159 views

Batch processing Topojson

Can i convert more than one shape file .shp to topojson. Can this be performed using batch processing.?? I can convert shape file to topojson one by one but i have about 6000 files and i don't want ...
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346 views

OGR merge shapefiles of different geom type into a single GeoJSON feature collection

I'd like to merge shapefiles of different geometry types into a single geojson feature collection, but OGR says it doesn't support update of GeoJSON files: $ ogr2ogr -f GeoJSON -t_srs crs:84 -lco ...
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1answer
228 views

topojson editor/viewer

I'm converting a map from geojson to topojson, and I'd like to validate that the conversion is ok. Unfortunately qgis doesn't seem to support topojson yet. I've found this excellent application ...
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1answer
65 views

simplilfy geojson file [duplicate]

I have a geojson file, but it's way too heavy for the app I need to develop I'd like to know what alternative do I have to make it lighter. I was thinking about simplifying it's shapes, and also ...
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2answers
374 views

How to merge TopoJSON features?

I currently have a coordinate based map of the US and it's states for topojson (https://github.com/mbostock/topojson). The coordinates are a JSON array (as topojson works), data looks like this: ...
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195 views

How to convert Shapefile to TopoJSON with grouping neighbor shapes by some criteria

I have a shapefile with countries, which I convert to GeoJSON using ogr2ogr and then converting that json to another TopoJSON, using topojson command-line tool. Everything works like charm, but now I ...
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3answers
2k views

D3 for maps---at what stage to bring in data to the geo?

I'd like to map a world choropleth for display with D3, a la: http://bl.ocks.org/mbostock/4206573 http://bl.ocks.org/jasondavies/4188334 I have a dataset I'd like to display that's keyed to ...
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2answers
475 views

What is topojson and how is it different than geojson?

This is a conceptual question. What are the differences between these? and what are the pros and cons of these formats?
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2answers
188 views

TopoJSON: how to calculate scale and translate?

Context: I'm using the topojson file format along with d3. Since I could not find a library in Python that handles this format, I'm writing one. I've got the topojson to other formats working. ...
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1answer
174 views

geojson -> topojson : no output

Trying to convert my geoJSON file into topoJSON so I downloaded topojson from npm and followed the instructions on gis.stackexchange Convert GeoJSON to TopoJSON basically the same as the topoJSON ...
2
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1answer
917 views

Conversion from Shapefile to TopoJSON format results in incorrect map when rendered using d3js

I am trying to build a map of Canada showing FSA boundaries using d3js. I got shape data from Statistics Canada ...
2
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1answer
1k views

Either GeoJson to TopoJson conversion problem, or projection-issue with D3.js

My 'handcrafted' cartogram (How to create contiguous area cartograms in QGIS or R?) is ready to embed in code - I want to present it online with D3.js. Therefore I produced a topoJSON file of it - ...
2
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1answer
259 views

Converting from shp to geojson fails

I'm following Mike Bostock's tutorial, let's make a map, but for a map of Mexico. I want to display state boundaries. I was able to get the map of Mexico from Natural Earth Data's world maps. My ...
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1answer
261 views

TopoJSON without Quantization

I have been investigating using TopoJSON files to map floor plans for various buildings. As GeoJSON these files render perfectly, however after converting to TopoJSON they are missing a lot of the ...
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3answers
437 views

How to properly convert landmass NaturalEarth data into GeoJSON?

100% Newbie. I've been following Mike's d3 Map Tutorial and I've come up against a challenge. I guess my question essentially boils down to: how does one generate the proper GeoJSON/TopoJSON files ...
3
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1answer
641 views

How to avoid corrupt geometries when translating between TopoJSON and GeoJSON?

I'm trying to display some geojson vector features on a leaflet map. The size of my GeoJSON is too big (25.4mb of data, 8.47mb gzipped), so I'm trying to use a TopoJSON format to reduce the size ...
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4answers
1k views

GeoJSON too bulky - what to do?

I am using leaflet.js to allow web users to select a region. Valid regions are US states, Canadian providences, and world countries (except for US and Canada). I constructed a shapefile myself using ...
22
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1answer
3k views

Convert GeoJSON to TopoJSON

Question How do you convert GeoJSON data to TopoJSON? Why Topojson files are often smaller than geojson and the conversion allows you to incrementally simplify a dataset, if you wish.
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2answers
677 views

How to reduce the file size of GeoJSON data?

For my project I am trying to convert the tiger shapefile information for us states into GeoJSON format However when I use the ogr2ogr tool the data file is about 20 MB. I have seen the geoJSON file ...