我有几个netcdf文件,想删除具有某些特征的数据并保存到新的netcdf文件。
文件具有纬度,经度和时间坐标,并且温度和风是可变的。这个想法是,如果风变量小于6 m / s,则将删除风和温度变量的所有信息(关于此纬度,经度和时间)。如何在python中执行此操作?
目前为止我有
from netCDF4 import Dataset
from datetime import *
import os
#-----------------------------------------------------------------------------------------------------------------------------------
path = '/home/Downloads/Arquivos_GOES_2018_OSISAF_NC/'
data_ini = datetime(2018,1,1,1,0,0)
data_end = datetime(2018,7,1,1,0,0)
IDval = 6 # minimo quality_level aceito
#-----------------------------------------------------------------------------------------------------------------------------------
DateTimeNow = data_ini
while DateTimeNow<=data_end:
namefile_net = DateTimeNow.strftime('%Y%m%d%H%M')+'00-OSISAF-L3C_GHRSST-SSTsubskin-GOES16-ssteqc_goes16_'+DateTimeNow.strftime('%Y%m%d_%H%M')+'00-v02.0-fv01.0.nc'
if os.path.isfile(path+namefile_net) == True:
data_net = Dataset(path+namefile_net)
tsm = data_net.variables['sea_surface_temperature'][0,:]-273.15
lat = data_net.variables['lat'][:]
lon = data_net.variables['lon'][:]
wind = data_net.variables['wind_speed'][0,:]
wind = np.where(qlv.mask==True,-1.0, qlv)
lon, lat = np.meshgrid(lon, lat) # criar uma matriz com lat e lon
tsm_area = tsm[yid,xid]
lon_area = lon[yid,xid]
lat_area = lat[yid,xid]
wind_area = wind[yid,xid]
if np.sum(wind>=IDval) > 0:
lon_area = np.where(qlv_area<IDval,-999.9,lon_area)
lat_area = np.where(qlv_area<IDval,-999.9,lat_area)
yid2, xid2 = seach_point(lon_area, lat_area, lon_point, lat_point)
```
似乎您的数据已经是numpy。这是一个主意(没有CDF,所以让我们想象第3列是风):
>>> y = np.zeros((4,4))
>>> data = np.zeros((4,4))
>>> data[:,3] = [1,12, 4, 9]
>>> data
array([[ 0., 0., 0., 1.],
[ 0., 0., 0., 12.],
[ 0., 0., 0., 4.],
[ 0., 0., 0., 9.]])
>>> data[ data[:,3] > 6]
array([[ 0., 0., 0., 12.],
[ 0., 0., 0., 9.]])