netcdf file read and write

I have a netcdf file A.nc containing monthly data from 2011 to 2020. Say the main data is for specific humidity. The variables are :

time

Size: 432x1

Dimensions: time

Datatype: double

Attributes:

bounds = 'time_bnds'

axis = 'T'

long_name = 'time'

standard_name = 'time'

units = 'days since 1850-01-01'

calendar = 'julian'

time_bnds

Size: 2x432

Dimensions: bnds,time

Datatype: double

plev

Size: 19x1

Dimensions: plev

Datatype: double

Attributes:

units = 'Pa'

axis = 'Z'

positive = 'down'

long_name = 'pressure'

standard_name = 'air_pressure'

lat

Size: 32x1

Dimensions: lat

Datatype: double

Attributes:

bounds = 'lat_bnds'

units = 'degrees_north'

axis = 'Y'

long_name = 'Latitude'

standard_name = 'latitude'

lat_bnds

Size: 2x32x432

Dimensions: bnds,lat,time

Datatype: double

lon

Size: 192x1

Dimensions: lon

Datatype: double

Attributes:

bounds = 'lon_bnds'

units = 'degrees_east'

axis = 'X'

long_name = 'Longitude'

standard_name = 'longitude'

lon_bnds

Size: 2x192x432

Dimensions: bnds,lon,time

Datatype: double

hus

Size: 192x32x19x432

Dimensions: lon,lat,plev,time

Datatype: single

Attributes:

_FillValue = 1.000000020040877e+20

standard_name = 'specific_humidity'

long_name = 'Specific Humidity'

comment = 'Specific humidity is the mass fraction of water vapor in (moist) air.'

units = '1'

original_units = '1.0'

javaaddpath('D:\SHUM\NetCDF file read\netcdf souceforge\mexcdf\netcdfAll-4.2.jar');
javaaddpath('D:\SHUM\NetCDF file read\netcdf souceforge\mexcdf\snctools\classes');
addpath ('D:\SHUM\NetCDF file read\netcdf souceforge\mexcdf\snctools');
addpath ('D:\SHUM\NetCDF file read\netcdf souceforge\mexcdf\mexnc');
addpath ('D:\SHUM\NetCDF file read\netcdf souceforge\mexcdf\netcdf_toolbox')


addpath ('D:\SHUM\NetCDF file read\netcdf souceforge\mexcdf\netcdf_toolbox\netcdf\ncsource')
addpath('D:\SHUM\NetCDF file read\netcdf souceforge\mexcdf\netcdf_toolbox\netcdf\nctype')
addpath('D:\SHUM\NetCDF file read\netcdf souceforge\mexcdf\netcdf_toolbox\netcdf\ncutility')
addpath('D:\SHUM\NetCDF file read\netcdf souceforge\mexcdf\netcdf_toolbox\netcdf')


% ncdisp ('E:\ENSO Work\omega\omega.mon.mean.nc')
% info=ncinfo('omega.mon.mean.nc');

data_Wwind=netcdf('J:\JOYDEB_All_Data\SNSR\SH300\hus_Amon_IITM-ESM_ssp585_r1i1p1f1_gn_20150116-20501216_v20200915.nc');  %  input address of data folder
ncid = netcdf.open('hus_Amon_IITM-ESM_ssp585_r1i1p1f1_gn_20150116-20501216_v20200915.nc','NC_NOWRITE');
% 
% level_Wwind=data_Wwind{'level'}(:);   %%%%level required for all level data
lat_Wwind=data_Wwind{'lat'}(:);
lon_Wwind=data_Wwind{'lon'}(:);
time_Wwind=data_Wwind{'time'}(:);
winddata_Wwind=data_Wwind{'hus'}(:);
time_datenum_Wwind = time_Wwind / 24 + datenum('1800-01-01 00:00:0');
Time_Wwind=datevec(time_datenum_Wwind);

>> How can I have the specific humidity data in 120x1 matrix, all months for this 10 years (monthly averaged for 10 years)? I have attached the code as far I could write.

[Cris LaPierre]

I would use the ncread function to extract the data from the *.nc file.

data_Wwind='J:\JOYDEB_All_Data\SNSR\SH300\hus_Amon_IITM-ESM_ssp585_r1i1p1f1_gn_20150116-20501216_v20200915.nc');  %  input address of data folder
lat_Wwind=ncread(data_Wwind,'lat');
lon_Wwind=ncread(data_Wwind,'lon');
time_Wwind=ncread(data_Wwind,'time');
winddata_Wwind=ncread(data_Wwind,'hus');

At this point, you have extracted the lat, lon, time, and hus data from the nc file. hus is a 192x32x19x432 matrix, corresponding to lon x lat x plev x time. I'm not sure how your time is organized, but there are 432 measurements total over the 10 years. I'm not sure how that breaks down to months (use your time variable to find that out),

Do you want to average the humidity values across all plev values, or just the values at the same plev?