Use D3.min to find lowest value that is not 0

问题

I'm trying to use D3 to find the lowest value in my dataset. However, I also have values that are 0, but I want D3 to find the lowest value that is not 0.

Currently I am using:

d3.min(data, function(d) {return d.houseValues; })

But obviously this returns 0 sometimes, when a 0 is found.

Is there a way to do this? Or is the only solution to build a normal for-loop with an if-statement to ignore the 0 values..?

Thanks!

回答1:

You can use the constant Infinity, since Math.min(Infinity, someNumber) always return someNumber (unless someNumber is also infinity). So it'll look like this:

smallest = d3.min(data, function(d) {return d.houseValues || Infinity; })

If needed, you can check smallest == Infinity, which would be true in the case that all house values were 0.

回答2:

Try filtering the data to remove zeroes first, e.g.

var noZeroes = data.filter(function(d) { return d.houseValues !== 0; });
d3.min(noZeroes, function(d) {return d.houseValues; })

来源：https://stackoverflow.com/questions/29261994/use-d3-min-to-find-lowest-value-that-is-not-0