Forum Discussion
Deneb - Vega Lite Color Gradient Per Category
Hi,
Just wondering if and how it is possible to set the color gradient for category within a visual rather than across the full visual.
The below example shows the gradient based all all categories but is is possible for the color gradient to be applied on each individual category.
{ "data": {"url": "data/cars.json"},
"mark": "rect",
"encoding": { "y": {"field": "Origin", "type": "nominal"},
"x": {"field": "Cylinders", "type": "ordinal"},
"color": {"aggregate": "mean", "field": "Horsepower"} },
"config": { "axis": {"grid": true, "tickBand": "extent"}
} }
Thanks in advance
DW868990, oh wow, apologies. It was so similar to an example on the vega-lite page, that I missed what you were actually after. Let me know if this is better. Happy to make additional tweaks if necessary. I took out the text in the boxes to match what you have. Can add it back in though if you like.
{ "$schema": "https://vega.github.io/schema/vega-lite/v5.json", "data": {"url": "data/cars.json"}, "facet": {"row": {"field": "Origin", "title": null}}, "title": { "text": "Mean Horsepower per Cylinder per Origin", "orient": "top", "anchor": "middle" }, "spec": { "encoding": { "y": {"field": "Origin", "type": "ordinal", "axis": null}, "x": {"field": "Cylinders", "type": "ordinal"} }, "layer": [ { "mark": "rect", "encoding": { "color": { "field": "Horsepower", "aggregate": "average", "type": "quantitative", "legend": { "direction": "horizontal", "orient": "right", "gradientLength": 100, "title": null } } } } ] }, "resolve": {"scale": {"y": "independent", "color": "independent"}}, "config": {"axis": {"grid": true, "tickBand": "extent"}} }
10 Replies
Hi DW868990. Not quite sure if this is what you're after (see below), this implementation utilizes faceting. If it is, consider marking this as the solution. If not, could you please clarify what you mean? I'm making the assumption that you want your category to be Cylinders.
{ "$schema": "https://vega.github.io/schema/vega-lite/v5.json", "data": {"url": "data/cars.json"}, "transform": [ { "aggregate": [{"op": "count", "as": "num_cars"}], "groupby": ["Origin", "Cylinders"] }, { "window": [{"field": "num_cars", "op": "average", "as": "avg num_cars"}], "groupby": ["Cylinders"], "frame": [null, null] }, { "window": [ {"field": "num_cars", "op": "count", "as": "record ct per cylinders"} ], "groupby": ["Cylinders"], "frame": [null, null] }, { "calculate": "((datum['num_cars']-datum['avg num_cars']))", "as": "variance" }, { "sort": [ {"field": "Cylinders"}, {"field": "num_Cars", "order": "descending"} ] } ], "facet": {"column": {"field": "Cylinders", "title": null}}, "title": { "text": "Count of Cars per Cylinder per Origin", "orient": "top", "anchor": "middle" }, "spec": { "encoding": { "y": {"field": "Origin", "type": "ordinal"}, "x": {"field": "Cylinders", "type": "ordinal", "axis": null} }, "layer": [ { "mark": "rect", "encoding": { "color": { "field": "num_cars", "type": "quantitative", "legend": { "direction": "vertical", "orient": "bottom", "gradientLength": 100, "title": null } } } }, { "mark": "text", "encoding": { "text": {"field": "num_cars", "type": "quantitative"}, "color": { "condition": {"test": "datum['variance'] < 0", "value": "black"}, "value": "white" } } } ] }, "resolve": {"scale": {"x": "independent", "color": "independent"}}, "config": {"axis": {"grid": true, "tickBand": "extent"}} }Thank you. Yes its nearly what i am after. Although the category i would be using is Origin in this example.
So for example say Europe ranged from 1 to 100
and then USA ranged from 1 to 1000
The color for the highest value for each category would be the same gradient/colour.Thanks for your help.
DW868990, how about this?
{ "$schema": "https://vega.github.io/schema/vega-lite/v5.json", "data": {"url": "data/cars.json"}, "transform": [ { "aggregate": [{"op": "count", "as": "num_cars"}], "groupby": ["Origin", "Cylinders"] }, { "window": [{"field": "num_cars", "op": "average", "as": "avg num_cars"}], "groupby": ["Origin"], "frame": [null, null] }, { "window": [ {"field": "num_cars", "op": "count", "as": "record ct per cylinders"} ], "groupby": ["Origin"], "frame": [null, null] }, { "calculate": "((datum['num_cars']-datum['avg num_cars']))", "as": "variance" }, { "sort": [ {"field": "Cylinders"}, {"field": "num_Cars", "order": "descending"} ] } ], "facet": {"row": {"field": "Origin", "title": null}}, "title": { "text": "Count of Cars per Cylinder per Origin", "orient": "top", "anchor": "middle" }, "spec": { "encoding": { "y": {"field": "Origin", "type": "ordinal", "axis": null}, "x": {"field": "Cylinders", "type": "ordinal"} }, "layer": [ { "mark": "rect", "encoding": { "color": { "field": "num_cars", "type": "quantitative", "legend": { "direction": "horizontal", "orient": "right", "gradientLength": 100, "title": null } } } }, { "mark": "text", "encoding": { "text": {"field": "num_cars", "type": "quantitative"}, "color": { "condition": {"test": "datum['variance'] < 0", "value": "black"}, "value": "white" } } } ] }, "resolve": {"scale": {"y": "independent", "color": "independent"}}, "config": {"axis": {"grid": true, "tickBand": "extent"}} }
Hi, looking at this question, I'm trying to create a similar image, but using one color.
Is there a way to duplicate the chart on the right, and if so, how?
Is Deneb the key to doing this?Hey TheBIGuy_PBI, this could definitely be accomplished with Deneb, but the Filled map core visual should suffice.
