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VisualizaçõesD3.js Heatmap colors based on variable value instead of value for the whole table
I want to create a heatmap which shows the heat/color based on the value of one variable over all groups but not over all variables.
Currently I have the following, where the color is based on the value over all values in the map:
Thats why almost everything is yellow because the Household net wealth in Luxembourg is just to high. My code for the rectangles is the following:
// Color Scale
var myColor = d3.scaleSequential()
.interpolator(d3.interpolateViridis)
.domain([d3.max(data, d=>d.value),d3.min(data, d=>d.value)]);
// add the squares
svg.selectAll()
.data(data, function (d) { return d.Country + ':' + d.variable; })
.enter()
.append("rect")
.attr("x", function (d) { return x(d.Country) })
.attr("y", function (d) { return y(d.variable) })
.attr("rx", 4)
.attr("ry", 4)
.attr("width", x.bandwidth())
.attr("height", y.bandwidth())
.style("fill", function (d) { return myColor(d.value) })
.style("stroke-width", 4)
.style("stroke", "none")
.style("opacity", 0.8)
.on("mouseover", mouseover)
.on("mousemove", mousemove)
.on("mouseleave", mouseleave)
}
My data is in long format like this:
| Country | Variable | Value |
|---|---|---|
| Australia | Var 1 | Value 1 |
| Australia | Var 2 | Value 2 |
| ... | ... | ... |
| Australia | Var 24 | Value 24 |
| Austria | Var 1 | Value 25 |
| ... | ... | ... |
| South Africa | Var 24 | Value 960 |
Do you have any ideas of how to change this so this would work? I could also transform the data.
Thanks you so much for your help and have great Tuesday!
1 Respostas
Responde à pergunta0
I changed the data I am supplying to the front end, by adding two columns: one column regarding the minimum value of the variable over all groups/countries and one column regarding the maximum value of the variable over all groups/countries. My dataset now looks the following way:
| Country | Variable | Value | min | max |
|---|---|---|---|---|
| Australia | Var 1 | Value 1 | Min(Var1) | Max(Var1) |
| Australia | Var 2 | Value 2 | Min(Var2) | Max(Var2) |
| ... | ... | ... | ... | ... |
| Australia | Var 24 | Value 24 | Min(Var24) | Max(Var24) |
| Austria | Var 1 | Value 25 | Min(Var1) | Max(Var1) |
| ... | ... | ... | ... | ... |
| South Africa | Var 24 | Value 960 | Min(Var24) | Max(Var24) |
By including a function which gives me the color variable based on the current variables min and max value I changed the code to the following:
//Color scale function
function colorPerVariable(minimun, maximum, value) {
var myColor = d3.scaleSequential()
.interpolator(d3.interpolateViridis)
.domain([minimum, maximum]);
return myColor(value);
}
// add the squares
svg.selectAll()
.data(data, function (d) { return d.Country + ':' + d.variable; })
.enter()
.append("rect")
.attr("x", function (d) { return x(d.Country) })
.attr("y", function (d) { return y(d.variable) })
.attr("rx", 4)
.attr("ry", 4)
.attr("width", x.bandwidth())
.attr("height", y.bandwidth())
//Changed part
.style("fill", function (d) { return colorPerVariable(minimum = d.min, maximum = d.max, value = d.value) })
//
.style("stroke-width", 4)
.style("stroke", "none")
.style("opacity", 0.8)
.on("mouseover", mouseover)
.on("mousemove", mousemove)
.on("mouseleave", mouseleave)
}