tic
[hmbc_spec hmbc_axes] = read_nmrp('hmbc.ft2',1); 
     % HMBC spectrum found in file hmbc.ft2
     % id first (direct) dimension as "donor", to perform indirect covariance
[hmbc_covar hmbc_covar_axes] = covar(hmbc_spec,'axes1',hmbc_axes);  
     % indirect covariance with matrix square root requires no other value/option pairs
write_covar2pipe(hmbc_covar, hmbc_covar_axes,'hmbc.covar'); 
     % write output to hmbc.covar
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