cnormsqfro

 Computes the squared Frobenius norm of X

 function Xnormfro = cnormsqfro(X)

 Returns the squared Frobenius norm of X. This function can be seen as 
 norm(...,'fro')^2 but is compatible with dlarrays and structs with fields
 real and imag. Supports both real and complex numbers.

 See also: manoptADhelp

0001 function Xnormfro = cnormsqfro(X)
0002 % Computes the squared Frobenius norm of X
0003 %
0004 % function Xnormfro = cnormsqfro(X)
0005 %
0006 % Returns the squared Frobenius norm of X. This function can be seen as
0007 % norm(...,'fro')^2 but is compatible with dlarrays and structs with fields
0008 % real and imag. Supports both real and complex numbers.
0009 %
0010 % See also: manoptADhelp
0011 
0012 % This file is part of Manopt: www.manopt.org.
0013 % Original author: Xiaowen Jiang, July. 31, 2021.
0014 % Contributors: Nicolas Boumal
0015 % Change log:
0016 
0017     if iscstruct(X)
0018         Xnormfro = cinnerprodgeneral(X, X);
0019         
0020     elseif isnumeric(X)
0021         if isreal(X) 
0022             Xnormfro = X(:)'*X(:);
0023         else
0024             Xnormfro = sum(real(conj(X(:)).*X(:)));
0025         end
0026         
0027     else
0028         ME = MException('cnormsqfro:inputError', ...
0029                         'Input does not have the expected format.');
0030         throw(ME);
0031     end
0032 
0033 end