netcdf 4 time

[jorge.conrado at cptec.inpe.br]

Hi,


I'm reading ndetcdf 4 data from NCEP Reanalyisis project.


I use to read the data: air_2010_2014_850hPa_d.nc

is four year daily data.

mport matplotlib.pylab as plt
from netCDF4 import Dataset, num2date, date2index, date2num
import pandas as pd
from mpl_toolkits.basemap import Basemap
import numpy as np
from jdcal import gcal2jd, jd2gcal

f = Dataset('air_2010_2014_850hPa_d.nc')

air = f.variables['air'][:]
time = f.variables['time']
lon = f.variables['lon'][:]
lat = f.variables['lat'][:]


lon, lat = np.meshgrid(lon, lat)


dates = num2date(time[:], time.units)


print dates


This is the date values:


[datetime.datetime(2010, 1, 1, 0, 0) datetime.datetime(2010, 1, 2, 0, 0)
  datetime.datetime(2010, 1, 3, 0, 0) ...,
  datetime.datetime(2014, 12, 29, 0, 0)
  datetime.datetime(2014, 12, 30, 0, 0)
  datetime.datetime(2014, 12, 31, 0, 0)]


Please, how can I get an arrya for each year, monht and day from the 
dates values and how can I get an specific day for my dates array.


Please anyone have any example of date2index for the netcdf 4.



This is the time for my netcdf data.

<type 'netCDF4._netCDF4.Variable'>
float64 time(time)
     long_name: Time
     delta_t: 0000-00-01 00:00:00
     avg_period: 0000-00-01 00:00:00
     standard_name: time
     axis: T
     units: hours since 1800-01-01 00:00:0.0
     actual_range: [ 1840824.  1884624.]
unlimited dimensions: time
current shape = (1826,)
filling on, default _FillValue of 9.96920996839e+36 used




Thanks in advance,


Conrado