wboykinm

WITH hgrid AS
  (SELECT CDB_HexagonGrid(ST_Expand(CDB_XYZ_Extent(/* INSERT TILE XYZ SOMEHOW */), CDB_XYZ_Resolution(/* CURRENT ZOOM */) * 15), CDB_XYZ_Resolution(/* CURRENT ZOOM */) * 15) AS cell)
SELECT hgrid.cell AS the_geom_webmercator,
       count(i.cartodb_id) AS points_count,
       count(i.cartodb_id)/power(15 * CDB_XYZ_Resolution(/* CURRENT ZOOM */), 2) AS points_density,
       1 AS cartodb_id
FROM hgrid,
  (SELECT *
   FROM /* TABLE NAME HERE */) i
WHERE ST_Intersects(i.the_geom_webmercator, hgrid.cell)

jlivni

// gmaps js api v2 polygon overlays -> geojson
overlayToGeoJSON = function(o){
  var feature={type:'Feature', geometry:{ type:'Polygon', coordinates:[[]]}};
  for (var i=0; i < o.latlngs.length; i++){
    feature.geometry.coordinates[0].push([o.latlngs[i].lng + o.reflng, o.latlngs[i].lat + o.reflat])
  }
  feature.properties = {hint:o.hint, html: o.infohtml}
  return feature;
}
var results={type: "FeatureCollection", features: []};

mourner

function getTileUrls(bounds, tileLayer, zoom) {
    var min = map.project(bounds.getNorthWest(), zoom).divideBy(256).floor(),
        max = map.project(bounds.getSouthEast(), zoom).divideBy(256).floor(),
        urls = [];

    for (var i = min.x; i <= max.x; i++) {
        for (var j = min.y; j <= max.y; j++) {
            var coords = new L.Point(i, j);
            coords.z = zoom;

mbostock

license: gpl-3.0

officeofjane

D3.js small multiple bar charts with tooltips. Follows Mike Bostocks's small multiples example. Tooltip code from here.

mhkeller

-- Census tract population is column dp0010001

WITH op AS
  (SELECT the_geom,
          cartodb_id,
          dp0010001,
          Row_number() OVER (
                             ORDER BY Cdb_latlng(/* Starting latitude */, /* Starting longitude */) <-> the_geom) AS row_number
   FROM /* Table name */ LIMIT /* Max census tracts queryable */),
     sm AS

kerryrodden

license: apache-2.0

benbalter

# Bulk convert shapefiles to geojson using ogr2ogr
# For more information, see http://ben.balter.com/2013/06/26/how-to-convert-shapefiles-to-geojson-for-use-on-github/

# Note: Assumes you're in a folder with one or more zip files containing shape files
# and Outputs as geojson with the crs:84 SRS (for use on GitHub or elsewhere)

#geojson conversion
function shp2geojson() {
  ogr2ogr -f GeoJSON -t_srs crs:84 "$1.geojson" "$1.shp"
}

caseycesari

These commands are all run within the psql command line tool.

Create table for tax year 2013 data

CREATE TABLE tx_2013 (
  Acct_Num varchar(9),
  Address text,
  Unit text,
  Homestd_Ex text,

Prop_Cat text,

tmcw

AJAX For Cats

I will assume that you are familiar with Javascript and HTML - read up on jsforcats.com if you need Javascript chops, and Learn HTML for HTML.

AJAX is a feature of Javascript and your browser that downloads new data after you initially request a page: so you live-update content and pull in new bits of content a user requests. AJAX is how the Pinterest home page keeps loading content when you scroll, and it's how Gmail can ring in new emails without requiring you to click 'refresh' all the time.

Let's clear things up. Like Javascript for Cats, it's best to use Google Chrome for this, and to use your web developer extensions.

Requests