How can I do a wind speed maps?

I have this problem: Find, with the 'ncdisp' command, the wind speed variable (u and v) 50 meters from height;

Use the 'ncread' command to save the matrices speed (lon x lat) on the X axis (u) and in Y axis (v) in a cell. Each row should represent the 24 data array of a day;

With the matrices of values of the hourly speed in X and Y, they must be transformed into speed in module. Subsequently, should be obtain the final daily mean speed. This have to be represented in a cell, again each row represent a day of analysis.

With the values of the final speed, one must create speed maps, with the command 'mesh', in 3D, which represent the speed values in a certain region from the globe.

Until now, I used this code. But if I'm wrong, please, correct me.

Thanks for any help!

if true
  % >> % find wind speed variable (50meters) with _ncdisp_% 
>> ncdisp ('MERRA2_400.tavg1_2d_slv_Nx.20180304.SUB.nc4','U50M')
>> ncdisp ('MERRA2_400.tavg1_2d_slv_Nx.20180304.SUB.nc4','V50M')
>> % _ncread_ to save speed arrays (lon x lat) in X-axis X (u) and Y-axis Y (v) %
>> X=ncread('MERRA2_400.tavg1_2d_slv_Nx.20180304.SUB.nc4','U50M');
>> Y=ncread('MERRA2_400.tavg1_2d_slv_Nx.20180304.SUB.nc4','V50M');
>> % save arrays in a cell array %
>> data = cell(1,2);
 for K = 1 : 2
data{K} = rand(138, 155, 24);
end
>> % all variables positives %
>> X=abs(X);
>> Y=abs(Y);
>> % find the mean values %
>> X= [X(:,1); X(:,2 )];
m1=mean(X)
>> Y= [Y(:,1); Y(:,2 )];
m2=mean(Y)
end

How can I finished it?

[KSSV]

How are the lat and lon? They are structured or scattered? Attach your nc file.