Getting error on interpolation function

[yoursweater]

I'm trying to change the fill-color of my layer based on two properties, and I'm getting an odd error:

Error: layers.fullcitylayer.paint.fill-color: color expected, array found

The Documentation is very clear that interpolation expressions can validly be used in place of a color.

Here's the code I'm attempting to enter in:

map.setPaintProperty('fullcitylayer', 'fill-color', ['interpolate',['linear'],['/', ['get', 'B19001_017'], ['/', ['get', 'ALAND'], 1000000]],10,'#00adef',100,'#212529',1000,'#ea950b',5000,'#e94e34'] )

Is this just a bug?

[jfirebaugh]

Hi @yoursweater. I'm not able to reproduce that error running that code. Could you provide a self-contained JSFiddle that demonstrates the issue?

[yoursweater]

This is embarrassing, but for some reason I'm having difficulty getting that set up as well. I can add a layer or load in a map without any difficulty locally, but my jsfiddle is refusing to work. Even using someone else's map, just doing this causes the map to fail to load:

    map.addLayer({
        "id": "pop-data",
        "type": "fill",
        "source": {
            type: 'vector',
            url: 'mapbox://yoursweater.6h1mo1cs'
        },
        "source-layer": "fullCityLayer",
        "paint": {
            "fill-color": "#ff69b4"
        }
    });

[anandthakker]

Thanks @yoursweater. I was able to reproduce this issue locally using the expression you provided in the original post. It looks like the issue is that, for one of the features, ALAND is 0, and we're failing to handle the resulting NaN properly. I'll retitle this issue to reflect that bug.

Meanwhile, a temporary workaround would be to replace ["get", "ALAND"] with ["max", ["get", "ALAND"], 1] (or some other suitable placeholder value besides 1)

[anandthakker]

Actually looks like we have an issue for this for functions already -- let's use that to track.

Duplicate of #4172