How to extract data from .nc file based on latitude, longitude, time and temperature?

Question

Sai Dhanush 2020-7-13

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/564035-how-to-extract-data-from-nc-file-based-on-latitude-longitude-time-and-temperature

评论： KSSV 2020-10-18

This is my first time trying to pull data from an netCDF file using MATLAB

here's what I did

clear all
close all
ncid = netcdf.open('uwnd.sig995.2016.nc','NC_NOWRITE');
lat = netcdf.getVar(ncid,0);
whos lat
lon = netcdf.getVar(ncid,1);
whos lon
time = netcdf.getVar(ncid,2);
whos time
wind = netcdf.getVar(ncid,3); %var3 wind 4x day
whos wind

I dont know how to extrat one year

and the temperature for these lat lon and time

Any help?

Thx in advance! Regards.

Below the data:

Source:
           C:\Users\admin\MATLAB\Projects\ure\my1948.nc
Format:
           netcdf4_classic
Global Attributes:
           Conventions   = 'COARDS'
           title         = 'mean daily NMC reanalysis (1948)'
           description   = 'Data is from NMC initialized reanalysis
                           (4x/day).  These are the 0.9950 sigma level values.'
           platform      = 'Model'
           history       = 'created 99/05/11 by Hoop (netCDF2.3)
                           Converted to chunked, deflated non-packed NetCDF4 2014/09'
           dataset_title = 'NCEP-NCAR Reanalysis 1'
           References    = 'http://www.psl.noaa.gov/data/gridded/data.ncep.reanalysis.html'
Dimensions:
           lon  = 144
           lat  = 73
           time = 366   (UNLIMITED)
Variables:
    lat 
           Size:       73x1
           Dimensions: lat
           Datatype:   single
           Attributes:
                       units         = 'degrees_north'
                       actual_range  = [90 -90]
                       long_name     = 'Latitude'
                       standard_name = 'latitude'
                       axis          = 'Y'
    lon 
           Size:       144x1
           Dimensions: lon
           Datatype:   single
           Attributes:
                       units         = 'degrees_east'
                       long_name     = 'Longitude'
                       actual_range  = [0         357.5]
                       standard_name = 'longitude'
                       axis          = 'X'
    time
           Size:       366x1
           Dimensions: time
           Datatype:   double
           Attributes:
                       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  = [1297320  1306080]
    air 
           Size:       144x73x366
           Dimensions: lon,lat,time
           Datatype:   single
           Attributes:
                       long_name               = 'mean Daily Air temperature at sigma level 995'
                       units                   = 'degK'
                       precision               = 2
                       least_significant_digit = 1
                       GRIB_id                 = 11
                       GRIB_name               = 'TMP'
                       var_desc                = 'Air temperature'
                       dataset                 = 'NCEP Reanalysis Daily Averages'
                       level_desc              = 'Surface'
                       statistic               = 'Mean'
                       parent_stat             = 'Individual Obs'
                       missing_value           = -9.969209968386869e+36
                       actual_range            = [188.29         315.3]
                       valid_range             = [185.16        331.16]

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

KSSV 2020-7-13

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/564035-how-to-extract-data-from-nc-file-based-on-latitude-longitude-time-and-temperature#answer_464963

在 MATLAB Online 中打开

There is a easier netCDF toolbox available. REad about ncdisp, ncread. These two commands are more than enough ti read data from the netCDF file.

ncfile = "C:\Users\admin\MATLAB\Projects\ure\my1948.nc" ; 
lon = ncread(ncfile,'lon') ; 
lat = ncread(ncfile,'lat') ; 
time = ncread(ncfile,'time') ; 
air = ncread(ncfile,'air') ; 