raster picker configuration readme

README.md

@@ -124,10 +124,51 @@ As well as these stylesheets.
 
 * All data comes from the Berkeley Ecoinformatics API, documented at https://ecoengine.berkeley.edu/docs/quickstart.html
 
-### Static Assets
-
-* /explore/index.html
-* /explore/config.js
+### Raster Picker Configuration
+
+The raster picker is configured in `js/configure-explore.js` as a data structure called `ECO.rasterPicker`.
+
+The `models` show up in the Scenario dropdown in Explore. The  `metrics` show up as Climate Models in Explore.
+
+Only `metrics` with the value `nex` set to `true` will appear in the dropdown. The slugs from `metrics` and `models` are combined to create valid slugs for the [Ecoengine Series API](https://ecoengine.berkeley.edu/api/series/).
+
+`metrics` can also take a `palette` to change the default color ramp. See available values in the `colormap` variable in `js/color-ramp.js`. These colors are passed as the API parameter `style` to Ecoengine to get tiles using that palette. The color ramp can also be configured in Explore using the dropdown below the color legend.
+
+```javascript
+ECO.rasterPicker = {
+  "models": [
+    {
+      "name": "modern",
+      "slug": "historical"
+    },
+    {
+      "name": "RCP 4.5",
+      "slug": "rcp45"
+    },
+    {
+      "name": "RCP 8.5",
+      "slug": "rcp85"
+    }
+  ],
+  "metrics": [
+    {
+      "name": "precipitation yearly average",
+      "slug": "pr_yr_ens-avg_amon",
+      "nex": true,
+      "palette": "YlGnBu",
+    },
+    {
+      "name": "maximum temperature ensemble average",
+      "slug": "tasmax_ens-avg_amon",
+      "nex": true,
+      "palette": "YlOrRd",
+    },
+
+    /* ... */
+
+  ]
+};
+```
 
 ## Photos