I have this geometric shape file, so no map of a city.
I store it in a GIS database as GeoJson. Now, I want to visualize the geojson data. I created the GeoJson data first with QGIS and exported it as Coordinate Reference System WGS 84 EPSG:4326. This is an example data of Shapefile one:
{
"type":"FeatureCollection",
"crs":{
"type":"name",
"properties":{
"name":"urn:ogc:def:crs:OGC:1.3:CRS84"
}
},
"features":[
{
"type":"Feature",
"properties":{
"Membership":0.000000,
"Membership_1":0.000000,
"Membership_2":0.000000,
"Membership_3":0.000000,
"Membership_4":0.000000,
"Membership_5":0.000000,
"Membership_6":0.000000,
"Membership_7":0.000000,
"Membership_8":0.000000,
"Membership_9":0.997638,
"Asymmetry":0.622090,
"Elliptic_F":0.368607,
"Density":1.720265,
"Radius_of_":2.122269,
"Rectangula":0.701797,
"Radius_of__1":0.341230,
"Main_direc":63.913780,
"Mean_red":251.683422,
"Mean_green":253.246326,
"Mean_blue":251.654027,
"Shape_inde":1.663047,
"Compactnes":2.373016,
"Roundness":1.781040,
"Border_ind":1.603306
},
"geometry":{
"type":"MultiPolygon",
"coordinates":[
[
[
[
0.0,
293.0
],
[
116.0,
293.0
],
[
116.0,
288.0
],
[
117.0,
288.0
],
[
117.0,
287.0
],
GeoJson Shapefile two the geometry is at the end:
{
"type":"FeatureCollection",
"crs":{
"type":"name",
"properties":{
"name":"urn:ogc:def:crs:OGC:1.3:CRS84"
}
},
"features":[
{
"type":"Feature",
"properties":{
"Ratio_red":0.337287,
"Ratio_gree":0.324566,
"Ratio_blue":0.338147,
"Asymmetry":0.233023,
"Elliptic_F":0.835821,
"Density":2.111246,
"Radius_of_":1.191572,
"Max_diff":0.040743,
"Rectangula":0.958607,
"Ratio_DSM_":1.001866,
"Diff_DSM_w":0.604676,
"LengthWidt":1.266667,
"Radius_of__1":0.894812,
"Main_direc":0.507535,
"Standard_d":4.209384,
"Standard_d_1":13.755727,
"Standard_d_2":12.358206,
"Standard_d_3":16.194083,
"Standard_d_4":21.437695,
"Standard_d_5":0.486436,
"Mean_slope":195.593284,
"Mean_slope_1":34.988806,
"Mean_red":143.451493,
"Mean_green":138.041045,
"Mean_blue":143.817164,
"Mean_DSM":324.615672,
"Shape_inde":1.038440,
"Mean_Diff_":0.604676,
"Compactnes":1.063433,
"Brightness":141.769900,
"Roundness":0.296759,
"Area_m2":1.715200,
"Border_ind":1.000000
},
"geometry":{
"type":"MultiPolygon",
"coordinates":[
[
[
[
-1.796831198293312,
46.775409744271464
],
[
-1.796815938387422,
46.775411620389058
],
The geometry is at the end of the file. I already tried things from this post but this works only for polygons and not multipolygons:
Venue/Indoor Map using D3.js and Geojson
I tried to visualize both with the following code:
<!DOCTYPE html>
<meta charset="utf-8">
<body>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script>
//Width and height
var w = 800;
var h = 800;
var colors = d3.scale.category20();
var projection = d3.geo.mercator()
.translate([w/2, h/2]);
var path = d3.geo.path()
.projection(projection);
//Define path generator
var path = d3.geo.path();
//Create SVG element
var svg = d3.select("body").append("svg").attr({width: w, height: h});
//Load in GeoJSON data
d3.json("imageOne.json", function(json) {
//Bind data and create one path per GeoJSON feature
svg.selectAll("path")
.data(json.features)
.enter()
.append("path")
.attr("d", path)
.style("fill", function(d,i){return colors(i)});
});
</script>
After running the script I get for the first data the following result:
Trying the script for the second image I get a white page.
I uploaded the two shape files Shapefiles
I struggled with this type of issue for days. Turns out the coordinate system used to serialize the map was projected instead of geometric, meaning that the data was already stored as x and y values on a 2d plane, not coordinates on a sphere.
Mike Bostock explains it very where in this google groups post:
https://groups.google.com/forum/#!topic/d3-js/OSp_sMZjfok
The issue is that d3.geo.projection is primarily intended for converting spherical coordinates to Cartesian coordinates, so when you create a d3.geo.projection instance from a raw projection function, it assumes spherical coordinates. Meaning, it assumes your raw projection function takes radians λ and φ as input, converts the input coordinates from degrees to radians, and performs adaptive resampling on the output.
All of which makes it great for implementing new geographic projections, but you’ll probably want to take a different route for implementing a custom Cartesian projection.
One approach is to implement a custom geometry stream. This is a lower-level API that lets you control exactly how the geometry is transformed, and is suitable for a simple scale and translate:
So armed with this knowledge, of course pumping the points thru a projection that expects the data to be spherical is going to result in a big mess.
If I viewed the shapefile or geojson in QGIS application, at the bottom right it shows the Coordinate Reference System (CRS) used to encode the values. In my case it was using 5320 (which is projected/2d) instead of something like 4326 (which is a geographic coordinate system)
来源：https://stackoverflow.com/questions/30359640/geojson-and-d3-js-multipolygon