[GIS] Visualizing layer using categorized AND graduated styles in QGIS

Question

I have a layer with road segments that come in five different classes and each have a value. I am trying to get a graduated color for the values (say, light blue for low and dark blue for high values) and at the same time make the highways (class 0) thicker than local roads (class 4) etc.

Now, usually I visualize the colors using about 10 classes (quantiles), so I'd end up defining somewhere around 50 rules: road class 1, value 0-100 – road class 1, value 100-500 and so on.

Is there a way to get there any quicker?

Using Version 2.18.10

Answer 1

Not sure if this is what you are aiming to:

(1) Select Graduate and choose "values" for Columns.

(2) Set your Color ramp to Blues, perhaps

(3) Click on Symbol: --Change... button to activate Symbol selector

(4) Click on the small Epsilon button (i.e. Data defined override) right to Width

(5) Enter suitable expression something like: (5 - "classes") * 2. (Probably 2 is too much...)