Question

我有两个NetCDF文件，一个覆盖美国大陆（数据集2），另一个仅覆盖东北（数据集1）。我试图将两个值相乘以创建一个数据集，但是在进行乘法运算后得到了ValueError。

import xarray

dataset1=xarray.open_dataset('../data/precip.nc')
print(dataset1)

输出：

<xarray.Dataset>
Dimensions:  (time: 24, x: 180, y: 235)
Coordinates:
  * time     (time) datetime64[ns] 2019-02-14 ... 2019-02-14T23:00:00
  * y        (y) float64 -4.791e+06 -4.786e+06 ... -3.681e+06 -3.677e+06
  * x        (x) float64 2.234e+06 2.238e+06 2.243e+06 ... 3.081e+06 3.086e+06
    lat      (y, x) float64 ...
    lon      (y, x) float64 ...
Data variables:
    z        (y, x) float64 ...
    crs      int32 ...
    PRECIP   (time, y, x) float32 ...

dataset2=xarray.open_dataset('../data/ratio.nc')
print(dataset2)

输出：

<xarray.Dataset>
Dimensions:     (lat: 272, lon: 480, nv: 2)
Coordinates:
  * lat         (lat) float64 21.06 21.19 21.31 21.44 ... 54.69 54.81 54.94
  * lon         (lon) float64 -125.9 -125.8 -125.7 ... -66.31 -66.19 -66.06
Dimensions without coordinates: nv
Data variables:
    lat_bounds  (lat, nv) float64 ...
    lon_bounds  (lon, nv) float64 ...
    crs         int16 ...
    Data        (lat, lon) float32 ...

# Merge datasets
data=xarray.merge([dataset1, dataset2], compat='override')
print(data)

输出：

<xarray.Dataset>
Dimensions:     (lat: 272, lon: 480, nv: 2, time: 24, x: 180, y: 235)
Coordinates:
  * time        (time) datetime64[ns] 2019-02-14 ... 2019-02-14T23:00:00
  * y           (y) float64 -4.791e+06 -4.786e+06 ... -3.681e+06 -3.677e+06
  * x           (x) float64 2.234e+06 2.238e+06 ... 3.081e+06 3.086e+06
  * lat         (lat) float64 21.06 21.19 21.31 21.44 ... 54.69 54.81 54.94
  * lon         (lon) float64 -125.9 -125.8 -125.7 ... -66.31 -66.19 -66.06
Dimensions without coordinates: nv
Data variables:
    z           (y, x) float64 ...
    crs         int32 ...
    PRECIP      (time, y, x) float32 ...
    lat_bounds  (lat, nv) float64 ...
    lon_bounds  (lon, nv) float64 ...
    Data        (lat, lon) float32 ...

# Get first hour of precip data
precip=data.PRECIP[0:, :, :]

# Get ratio data
slr=data.Data

# Multiply to get snowfall
snow=slr*precip

最后一行给我这个错误：

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-41-b9ed8e05f451> in <module>
----> 1 snow=slr*precip

~/.local/lib/python3.7/site-packages/xarray/core/dataarray.py in func(self, other)
   2597             variable = (
   2598                 f(self.variable, other_variable)
-> 2599                 if not reflexive
   2600                 else f(other_variable, self.variable)
   2601             )

~/.local/lib/python3.7/site-packages/xarray/core/variable.py in func(self, other)
   2034                 new_data = (
   2035                     f(self_data, other_data)
-> 2036                     if not reflexive
   2037                     else f(other_data, self_data)
   2038                 )

ValueError: iterator is too large

Answer 1

已解决https://gis.stackexchange.com/questions/339463/using-xarray-to-resample-and-merge-two-datasets

slr_interpolate = slr.interp(lat=precip["lat"], lon=precip["lon"])

mpe_snowfall=slr_interpolate.Data*precip.Data

将具有不同维度的xarray数据集相乘

1 个答案: