Copyright 1998, 1999, 2000, Jeffrey A. Walker
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Copyright 1998, 1999, 2000, Jeffrey A. Walker |
About: QuicKurve estimates the local curvature, k, along a line segment using a parametric spline. The program can find interpolated curvatures or be used simply to find interpolated values of the line itself. The algorithm used for the spline is from
Woltring HJ. 1986. A Fortran package for generalized, cross-validatory spline smoothing and differentiation. Advances in Engineering Software 8: 104-107.
Curvature is estimated from the first and second derivatives of the function. A paper comparing the spline and other differentiation algorithms is available:
Walker, J.A. (1998) Estimating velocities and accelerations of animal locomotion: A simulation experiment comparing numerical differentiation algorithms. Journal of Experimental Biology, 201, 981-985.
and the software QuickSAND, Quick Smoothing And Numerical Differentiation for the Power Macintosh, fully implements all of the algorithms in the paper.
Tab delimited with figures in rows and coordinates in columns. No row or column labels. See sample file for example.
X1 [TAB] Y1 [TAB] X2 [TAB] Y2 [TAB] X3 [TAB] Y3 [TAB] X4 [TAB] Y4...
X1 [TAB] Y1 [TAB] X2 [TAB] Y2 [TAB] X3 [TAB] Y3 [TAB] X4 [TAB] Y4...
X1 [TAB] Y1 [TAB] X2 [TAB] Y2 [TAB] X3 [TAB] Y3 [TAB] X4 [TAB] Y4...
X1 [TAB] Y1 [TAB] X2 [TAB] Y2 [TAB] X3 [TAB] Y3 [TAB] X4 [TAB] Y4...
Tab delimited with figures in rows and coordinates in columns. No row or column labels. See sample file for example.
1 [TAB] X1 [TAB] Y1 [TAB] X2 [TAB] Y2 [TAB] X3 [TAB] Y3 [TAB] X4 [TAB] Y4...
2 [TAB] X1 [TAB] Y1 [TAB] X2 [TAB] Y2 [TAB] X3 [TAB] Y3 [TAB] X4 [TAB] Y4...
3 [TAB] X1 [TAB] Y1 [TAB] X2 [TAB] Y2 [TAB] X3 [TAB] Y3 [TAB] X4 [TAB] Y4...
4 [TAB] X1 [TAB] Y1 [TAB] X2 [TAB] Y2 [TAB] X3 [TAB] Y3 [TAB] X4 [TAB] Y4...
Not implemented
Opens two columns of xy data from multiple frames (=rows) into a single frame.
X1 [TAB] Y1 [TAB]
X1 [TAB] Y1 [TAB]
X1 [TAB] Y1 [TAB]
X1 [TAB] Y1 [TAB]
X1 [TAB] Y1 [TAB]
X1 [TAB] Y1 [TAB]
...