I have a nc file with 145 long, 129 lat and 10227 time values, I want to change this daily data (10,227) to monthly values. What could be easy way?

Actually, this is a climate data and I need monthly values from which I shall create seasons and plot in map form.

Answer 1

[John BG]

Hi Neha Kanda

this is John BG <mailto:[e-mail] [e-mail]>

1.

why more longitudes than latitudes: are there missing latitudes, or same longitude repeats along diverse longitudes?

2.

Same for time stamps, please confirm that you have many void time stamps, without coordinates I mean.

3.

Any chance for you to attach a sample of the data described in your question?

appreciating time and attention, awaiting answer

[Neha Kanda]

Actually, I am working on climate data of indian subregion. Data is available in Netcdf format. Its temporal resolution is daily. So for 28 years, I have daily data which is almost 10227 days. I wish to convert this daily data into monthly/ seasonal data within that netcdf format. After that I would like to compare the results of this model with other models spatially, for that I need to convert netcdf to image/raster format.

[John BG]

so far, without a sample of the data to process, I have the impression that your question gets solved by translating the netcdf file to a MATLAB structure.

Once the data in a MATLAB structure, it's straight forward to get the data you want.

Please have a look at Lazerson's function read_netcdf

https://www.mathworks.com/matlabcentral/fileexchange/28556-read-netcdf?s_tid=srchtitle

If you attach a sample of the data to your question I will use that function or other available in the MAthworks file exchange related to NetCDF to then obtain MATLAB format data to work with.

Regards

John BG

<mailto:[e-mail] [e-mail]>

Answer 2

[KSSV]

You should be having dates in your hand.......read the dates....pick the months and calculate the mean of monthly data.

[Neha Kanda]

Yeah that's fine but then how to convert the results back to netcdf and then a raster image.

[Neha Kanda]

Actually, I am working on climate data of indian subregion. Data is available in Netcdf format. Its temporal resolution is daily. So for 28 years, I have daily data which is almost 10227 days. I wish to convert this daily data into monthly/ seasonal data within that netcdf format. After that I would like to compare the results of this model with other models spatially, for that I need to convert netcdf to image/raster format.

[KSSV]

It is not a deal..it can be done...you need to get indices of months you want and run mean on the roster...the output would be a raster itself...it can be then written to NC file..

Answer 3

[Peter Perkins]

This seems like it could be easily solved using retime on a timetable, but there's not enough information in you post to go on.

[Neha Kanda]

Thanks Peter But since I am new to MATLAB, could you pls tell more about this retime option. Actually, I am working on climate data of indian subregion. Data is available in Netcdf format. Its temporal resolution is daily. So for 28 years, I have daily data which is almost 10227 days. I wish to convert tjis daily data into monthly/ seasonal data within that netcdf format. After that I would like to compare the results of this model with other models spatially, for that I need to convert netcdf to image/raster format.