查找表
如果您拥有完整的表,就不需要插值,只需查找最近的(x,y)值的索引并在表中使用它即可。
In [1]: import numpy
...: x = numpy.array([1.23, 2.63, 4.74, 6.43, 5.64])
...: y = numpy.array([2.56, 4.79, 6.21])
...: data = numpy.array([[0, 0, 1, 0, 1],
...: [0, 1, 1, 1, 0],
...: [1, 0, 0, 0, 0]])
...:
...: def lookupNearest(x0, y0):
...: xi = numpy.abs(x-x0).argmin()
...: yi = numpy.abs(y-y0).argmin()
...: return data[yi,xi]
In [2]: lookupNearest(5.1, 4.9)
Out[2]: 1
In [3]: lookupNearest(3.54, 6.9)
Out[3]: 0
最近邻插值
scipy.interpolate.NearestNDInterpolator
对于由散点组成的数据非常有用。
例如,对于像下面这样的数据:
其中红色=1、蓝色=0
In [4]: points = numpy.array([[1.1, 2.5],
...: [1.5, 5.2],
...: [3.1, 3.0],
...: [2.0, 6.0],
...: [2.8, 4.7]])
...: values = numpy.array([0, 1, 1, 0, 0])
In [5]: from scipy.interpolate import NearestNDInterpolator
...: myInterpolator = NearestNDInterpolator(points, values)
In [6]: myInterpolator(1.7,4.5)
Out[6]: 1
In [7]: myInterpolator(2.5,4.0)
Out[7]: 0
scipy.interpolate.NearestNDInterpolator
来实现它。但是,我想知道它对我的问题有多好和有效。 - A.M.