Biology Reference
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FIGURE 3.9 Procrustes superimposition. (A) Two triangles; (B) two centered triangles; (C) centered and scaled
triangles; (D) finding the angle of rotation; (E) centered, scaled and rotated triangles.
We can apply these operations to two triangles shown in Figure 3.9A . One has coordinates
(
0.72) and
(1.55, 0.82). The first step is to center them by subtracting the coordinates of the centroid,
and again we calculate the coordinates of the centroid by computing the arithmetic averages of
the X -and Y -coordinates. For the first
1,
1), (1,
1) and (0, 1) and the other has coordinates (1.07,
1.64), (3.10,
2
2
2
2
2
triangle,
the X -coordinate of
the centroid is
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