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I'm not too familiar with the D3 mercator projection function, and I'm getting some unexpected results. I'd like to project the following latitude and longitude (somewhere in Mexico):

var geo = [19, -99]

I define my mercator projection using d3

var projection = d3.geo.mercator();
projection(geo)
> [529.7418836818384, NaN]

which is a point obviously not on a map. What exactly am I doing wrong? Thanks!

Michael
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1 Answers1

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Javascript has it's lat and long round the opposite way to the rest of the world, so what you've given D3 is a longditue of 19 and a latitude of -99. Obviously there is no latitude of -99 hence the NaN. Now if you just reverse your geo variable to 

var geo = [-99, 19]

all should be good.

user1614080
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