Dear Takele;

It's a commen problem. In fact sometimes MatLab rotate NetCDF files, so you should be care of that.

May I ask you send me one of your NetCDF files?!

Best

Dear Muhammad,

Thank you for your response. I added one of my netcdf files here. Thanks

You might want to try CDO. You should be aware that different interpolation methods give different results. Please note the interpolation method that suits the variable you are trying to extract.

Dear Takele;

I'm so sorry for my late reply, and also I am glad that my previous answer was right.

The NetCDF file which you attached is the output of EC-EARTH climate model for maximum temperature under RCP4.5 scenario, over Africa in 0.44 degree of spacial and daily temporal resolution, which was dynamically downscaled by CLM regional climate model, under CORDEX project.

If you use this code in MatLab, you will have image 1 as a result:

>> clear; clc;

>> data=ncread('tasmax_AFR-44_ICHEC-EC-EARTH_rcp45_r12i1p1_CLMcom-CCLM4-8-17_v1_day_20060101-20101231.nc','tasmax');

>> data=mean(data,3);

>> pcolor(data);

which is a rotated image of Africa, so it means you should rotate your data, as below:

>> clear; clc;

>> data=ncread('tasmax_AFR-44_ICHEC-EC-EARTH_rcp45_r12i1p1_CLMcom-CCLM4-8-17_v1_day_20060101-20101231.nc','tasmax');

>> data=mean(data,3);

>> data=data';

>> pcolor(data);

That will make image 2.

If you have any more question about MatLab or maybe Climate Change, or CORDEX project, I am here.

Also I recommended Oluwafemi's answer, but I should notice you that CDO is available in Linux distribution, so if you want to try that, I suggest you Linux Ubuntu 16.04 distribution, then I will help with CDO.

Hope it helps

Best

Dear Muhammad and Oluwafemi,

Thank you very much for your response to my question. I'm not using linux so that I can't apply CDO.

Muhammad, thank you again for your interest to help me further. Sorry I haven't understood why you use data=mean(data,3); I mean why do we need to use mean?

With regard to the rotation, I extracted the data from each grid point one by one . I don't think that the rotation affects the data when you extract data for each grid points separately. I think the rotation affects data when you extract the whole data at once. For example, I extracted data for a grid point with rlon and rlat of 145 and 121, respectively. Hence, the value for this point is not affected by rotation because it is only one point.

My next question is if you have matlab codes for bias correction methods (delta change, power tranformation and quantile mapping), and also I need to know how to combine data in different excel workbook? For example, we can extract only five years climate data from one file and we have a number of 5 years data. Thus, can we easily cobine these data in matlab?

Thank you again for your cooperation.

Dear Takele;

I am sorry for my late reply.

I used mean to show the mean of the parameter over Africa, so you could easily select each day you want.

If you rotate a file the cornet will rotate too, so I can not accept your response!!

I should search in my files (I have delta change code), but I suggest you to write it by yourself. (Don't worry. I am here, and I want ask you to send me some messages if I forgot answering you).

yeah, it's so easy, you first should read your excel files. The command is:

xlsread

then you'll be able to combine your data by:

horzcat or vertcat.

These links may help you:

https://www.mathworks.com/help/matlab/ref/xlsread.html

https://www.mathworks.com/help/matlab/ref/horzcat.html

https://www.mathworks.com/help/matlab/ref/vertcat.html

Best.

Thank you a lot Muhammad

Dear Dr. MuhammadReza

I have seen your responses for Takle Gadissa’s problem. Similar to Takele, I am also processing NetCDF files in Matlab in Windows (not linux system). As you suggest for Takele, the matlab output for my case is also rotated clockwise by 90 degree. The figure becomes meaningful when I rotate the file by 90 degree anticlockwise by the mat command rot90 (variable ?)

But you prefer to use transpose that data rather than your suggestion of degreeanticlockwise rotation

Does this rotation is acceptable or it might bring an inherited problem?

Looking forward to receiving your comments.

Sincerely,

Dear Eyale;

It's acceptable. but you should care about the location of your study area.

If you need any more help, send me a message.

Best

Good day Dr Muhammad. I have managed to plot SST and Chlorophyll-a satellite datasets from Sentinel 3A Sea and Land Surface Temperature  Radiometer (SLSTR)  and Sentinel 3A Ocean Land Colour Instrument (OLCI). However, the SST datasets have errors from clouds. I have been tryng to fix the error t ono avail. How do i do this?

Also, how ot i do basic stats in Matlab?

Thanks

Dear MuhammadReza Tabatabaei can u plz help me?

I am trying to extract data for a particular location using CDO, ARCMAP and R.

But all these give different results.

please review the netcdf file along with diff commands/codes of above mentioned softwares which I am using with their outputs.

https://drive.google.com/drive/folders/1MLbLhv6FHomDvSGPCbzI5IWg8hWyWiFG?usp=sharing

https://stackoverflow.com/a/71065249/18161110

I came across this issue too. My observation regarding this issue..