python中不同维数数组的二维插值
我有三个二维数组,形状为(100100)。 每个阵列看起来像:python中不同维数数组的二维插值,python,numpy,multidimensional-array,scipy,interpolation,Python,Numpy,Multidimensional Array,Scipy,Interpolation,我有三个二维数组,形状为(100100)。 每个阵列看起来像: x = [[-104.09417725 -104.08866882 -104.0831604 ..., -103.8795166 -103.87399292 -103.86849976] ..., [-104.11058044 -104.10507202 -104.09954834 ..., -103.89535522 -103.88983154 -103.88430786] [-104.11141968 -104.10591
x =
[[-104.09417725 -104.08866882 -104.0831604 ..., -103.8795166 -103.87399292
-103.86849976]
...,
[-104.11058044 -104.10507202 -104.09954834 ..., -103.89535522
-103.88983154 -103.88430786]
[-104.11141968 -104.10591125 -104.10038757 ..., -103.89614868 -103.890625
-103.88513184]]
y =
[[ 40.81712341 40.81744385 40.81776428 ..., 40.82929611 40.82960129
40.82990646]
...,
[ 40.98789597 40.9882164 40.98854065 ..., 41.00011063 41.00041199
41.00072479]]
z =
[[ 1605.58544922 1615.62341309 1624.33911133 ..., 1479.11254883
1478.328125 1476.13378906]
...,
[ 1596.03857422 1600.5690918 1606.30712891 ..., 1598.56982422
1594.90454102 1594.07763672]]
我还有两个1-d数组,分别是x1和y1。这些x1和y1分别在x和y的范围内,例如:
x1 = [ 104.07794 104.03169 104.03352 104.03584 104.03835 104.04085
104.04334 104.07315 104.07133 104.07635 104.07916 104.0321
104.03481 104.03741 104.04002 104.04366 104.04572 104.04787
...................................................................
103.92937 103.89825 103.90027 103.90253 103.90352 103.90375
103.89922 103.89931 103.90145 103.90482 103.90885 103.91058
103.91243 103.91525 103.91785 103.92078 103.97814]
y1 = [ 40.9542 40.96922 40.96733 40.96557 40.96377 40.96218 40.96043
40.95446 40.95686 40.95296 40.95184 40.94984 40.94834 40.9469
40.94538 40.94287 40.94154 40.94008 40.93824 40.93705 40.93579
.........................................................................
40.89675 40.9015 40.90044 40.89948 40.89766 40.89513 40.88374
40.88118 40.87915 40.87933 40.87917 40.878 40.87675 40.87598
40.87515 40.87421 40.91258]
在(104.07794,40.9542)、(104.03169,40.96922)等指数之后,x1和y1彼此对应为(x1,y1)。
这里我想要得到的是z1,对应于(x1,y1)被x,y,z插值。
为此,我编写了如下代码:
x1,y1 = np.meshgrid(x1,y1)
f = interpolate.interp2d(x,y,z,kind='linear')
or
f = interpolate.Rbf(x,y,z,function='linear')
z1 = f(x1,y1)
但是,我不想将x1,y1转换为二维网格,因为这个函数会填充我不喜欢填充的网格点。所以,我想插值x1,y1而不转换为2d网格,但这些2d插值方法似乎要求x,y和x1,y1具有相同的尺寸。有没有办法在不使x1,y1和x,y的尺寸相同的情况下进行插值?
非常感谢。
艾萨克我不太清楚你所说的
x,y和x1,y1具有相同的维度
我可以构建一组输入数据:
In [294]: x,y=np.meshgrid(np.arange(10),np.arange(8))
In [295]: z=x+y
In [296]: f=interpolate.Rbf(x,y,z,kind='linear')
In [297]: x.shape
Out[297]: (8, 10)
我之所以使用meshgrid
,是因为它是生成一对二维阵列的最简单方法,可以生成一个合理的曲面。实际上,interp2d不喜欢使用此曲面
我可以将另一组点定义为2个一维阵列。点的数量与桥的数量或定义曲面的点的布局无关。我只需要给出一个(x1,y1)对,它对应于定义曲面的(x,y,z)三元组
In [298]: x1=np.linspace(0,10,15)
In [299]: y1=np.linspace(0,10,15)
In [300]: f(x1,y1)
Out[300]:
array([ 1.78745907e-13, 1.42752327e+00, 2.85761392e+00,
4.28560518e+00, 5.71422460e+00, 7.14293770e+00,
8.57139192e+00, 1.00000000e+01, 1.14285329e+01,
1.28573610e+01, 1.42852315e+01, 1.57040689e+01,
1.70924026e+01, 1.84049594e+01, 1.95946258e+01])
x
是2d这一事实并不重要;我可以将输入变平。interp2d
的文档特别提到对多维输入执行此操作
f1=interpolate.Rbf(x.flatten(), y.flatten(), z.flatten(), kind='linear')
插值点也可以以二维形状排列
f(x1.reshape((3,5)), y1.reshape((3,5)))
相同的插值,只是排列在(3,5)数组中
interp2d
的操作有些不同。使用“立方体”似乎比使用“线性”更快乐(我还没有探究原因):
结果是(x1.shape,y1.shape)
-它将x1,y1
视为定义类似网格的曲面
In [298]: x1=np.linspace(0,10,15)
In [299]: y1=np.linspace(0,10,15)
In [300]: f(x1,y1)
Out[300]:
array([ 1.78745907e-13, 1.42752327e+00, 2.85761392e+00,
4.28560518e+00, 5.71422460e+00, 7.14293770e+00,
8.57139192e+00, 1.00000000e+01, 1.14285329e+01,
1.28573610e+01, 1.42852315e+01, 1.57040689e+01,
1.70924026e+01, 1.84049594e+01, 1.95946258e+01])
但我可以提取对角线,得到与Rbf
基本相同的值(除了两端):
因此,使用Rbf
可以精确地指定插值的位置,而interp2d
可以指定二维空间的x,y
坐标。如我前面写的Rbf
答案所示,输入(x
和x1
)都是1d数组。在这种情况下,您可能需要展平二维阵列。
In [329]: z1.diagonal()
Out[329]:
array([ 7.61803576e-18, 1.42857137e+00, 2.85714294e+00,
4.28571419e+00, 5.71428543e+00, 7.14285905e+00,
8.57142306e+00, 1.00000000e+01, 1.14287955e+01,
1.28551995e+01, 1.41778962e+01, 1.54127554e+01,
8.99313361e+00, 1.60000000e+01, 1.60000000e+01])