Geom.density2d with Scale transformation

[Mattriks]

Example from julia discourse

x = [0.025, 0.028, 0.035, 0.036, 0.037, 0.039, 0.039, 0.041, 0.041, 0.041, 0.042, 0.043, 0.045, 0.047, 0.049, 0.051, 0.053, 0.053, 0.055, 0.056, 0.057, 0.057, 0.059, 0.063, 0.063, 0.067, 0.067, 0.069, 0.07, 0.072, 0.073, 0.075, 0.076, 0.076, 0.078, 0.082, 0.083, 0.083, 0.084, 0.085, 0.085, 0.086, 0.09, 0.092, 0.092, 0.093, 0.095, 0.095, 0.096, 0.103, 0.103,
0.104, 0.104, 0.105, 0.105, 0.106, 0.107, 0.107, 0.108, 0.109, 0.11, 0.117, 0.119, 0.119, 0.12, 0.126, 0.133, 0.133, 0.135, 0.135, 0.135, 0.137, 0.138, 0.141, 0.144, 0.144, 0.145, 0.145, 0.146, 0.146, 0.149, 0.151, 0.155, 0.155, 0.159, 0.162, 0.162, 0.163, 0.164, 0.167, 0.17, 0.171, 0.172, 0.179, 0.181, 0.187, 0.187, 0.188, 0.188, 0.201, 0.204, 0.204, 0.205, 0.208, 0.208, 0.213, 0.214, 0.214, 0.218, 0.221, 0.222, 0.23, 0.231, 0.238, 0.239, 0.245, 0.245, 0.25, 0.256, 0.256, 0.258, 0.262, 0.262, 0.263, 0.264, 0.267, 0.269, 0.273, 0.273, 0.276, 0.279, 0.288, 0.292, 0.296, 0.296, 0.297, 0.298, 0.301, 0.322, 0.324, 0.328, 0.332, 0.336, 0.341, 0.347, 0.354, 0.357, 0.365, 0.376]
y = [0.018, 4.0, 0.288, 0.157, 0.037, 0.163, 0.06499999, 1.0, 0.09199999, 0.203, 0.26, 0.028, 0.243, 4.0, 2.0, 0.852, 58.0, 4.0, 0.023, 2.48, 4.0, 3.0, 14.0, 37.3, 0.121, 2.0, 12.0,
4.0, 19.0, 4.0, 0.038, 1.0, 2.0, 0.146, 0.061, 0.127, 2.0, 203.0, 2.0, 2.0, 0.278, 2.0, 0.229, 2.0, 0.3, 4.0, 4.0, 0.146, 289.0001, 4.0, 2.0, 2.0, 0.163, 1.0, 0.266, 4.0, 3.0, 1.0, 9.0, 3.0, 0.171, 1.0, 0.264, 10.0, 0.374, 1.0, 2.0, 2.0, 25.0, 2.0, 0.582, 2.0, 15.0, 2.0, 2.0, 3.0, 2.0, 2.0, 2.0, 1.93, 9.0, 2.0, 19.0, 0.684, 4.0, 2.0, 2.0, 2.0, 19.0, 2.0, 6.0, 2.0, 5.0, 2.0, 4.0, 1351.0, 3.0, 2.0, 4.0, 4.0, 12.0, 9.0, 6.0, 6.0, 6.0, 1291.0, 5.0, 79.00001, 28.0, 7.0, 5.0, 60.0, 16.0, 15.0, 14.0, 49.0, 9.0, 19.0, 26.0, 35.0, 79.00001, 26.0, 4.0, 192.0, 79.00001, 26.0, 35.0, 148.0, 31.0, 46.99999, 79.00001, 456.0, 88.0, 21.0, 149.0, 31.0, 465.0001, 19.0, 81.00001, 48.0, 139.0, 938.9999, 303.0, 214.0, 440.9999, 168.0, 367.0, 196.0, 437.9999]

plot(x=x, y=y, Geom.point, Geom.density2d, Scale.y_log10)

DomainError with -0.014589995486293805: NaN result for non-NaN input.

The issue here actually lies wtih Stat.contour. In Gadfly, the Stats are applied after the scales are transformed, but in these lines, the user supplied Scales are applied a second time. Only a regular scale needs to be applied the second time. I'll open a PR sometime soon.