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This diagram image could be re-created using vector graphics as an SVG file . This has several advantages; see Commons:Media for cleanup for more information. If an SVG form of this image is available, please upload it and afterwards replace this template with {{ vector version available | new image name }} . It is recommended to name the SVG file “CIExy1931 MacAdam.svg”—then the template Vector version available (or Vva ) does not need the new image name parameter.

MacAdam(1942) ellipses plotted on the CIE xy 1931 chromaticity diagram. Ellipses are 10 x actual size.

Data taken from Günter Wyszecki and Walter Stanley Stiles, Color Science: Concepts and Methods, Quantitative Data and Formula (2nd edition), Wiley-Interscience. (July 28, 2000). ISBN 0-471-39918-3 , Table 2(5.4.1). Each ellipse is centered at [x,y] in the CIE (xy) chromaticity coordinates, with major and minor radii a and b respectively. t is the angle in degrees of the major axis with respect to the x axis, with positive angles going counter-clockwise.

  x     y  10^3a 10^3b t
0.160 0.057 0.85 0.35  62.5
0.187 0.118 2.20 0.55  77.0
0.253 0.125 2.50 0.50  55.5
0.150 0.680 9.60 2.30 105.0
0.131 0.521 4.70 2.00 112.5
0.212 0.550 5.80 2.30 100.0
0.258 0.450 5.00 2.00  92.0
0.152 0.365 3.80 1.90 110.0
0.280 0.385 4.00 1.50  75.5
0.380 0.498 4.40 1.20  70.0
0.160 0.200 2.10 0.95 104.0
0.228 0.250 3.10 0.90  72.0
0.305 0.323 2.30 0.90  58.0
0.385 0.393 3.80 1.60  65.5
0.472 0.399 3.20 1.40  51.0
0.527 0.350 2.60 1.30  20.0
0.475 0.300 2.90 1.10  28.5
0.510 0.236 2.40 1.20  29.5
0.596 0.283 2.60 1.30  13.0
0.344 0.284 2.30 0.90  60.0
0.390 0.237 2.50 1.00  47.0
0.441 0.198 2.80 0.95  34.5
0.278 0.223 2.40 0.55  57.5
0.300 0.163 2.90 0.60  54.0
0.365 0.153 3.60 0.95  40.0

Plots were made as parametric in f where f ranged from 0 to 2 pi

 aa=a[i]*cos(f)
 bb=b[i]*sin(f)
 xx=x[i]+aa*cos(t[i])-bb*sin(t[i])
 yy=y[i]+aa*sin(t[i])+bb*cos(t[i])
 plot,xx,yy

Please see Image:CIExy1931.png for a description of how this image was made.