openfig has the error 'The value of 'Filename' is invalid. It must satisfy the function: ischar.'

I am opening figures in a loop but I get error

Error using openFigure
The value of 'Filename' is invalid. It must satisfy the function: ischar.

Error in openfig>localGetFileAndOptions (line 98)
ip.parse(args{:});

Error in openfig (line 37)
[filename, reuse, visibleAction] = localGetFileAndOptions(varargin);

f_range_name = [ {'MI_.5Hz.fig'}, {'MI_.525.fig'}, {'MI_.55.fig'}, ...
    {'MI_.575.fig'}, {'MI_.6.fig'}];

   for j = 1:length(temp_f)
          [~,I]= min(f_range - temp_f(j));

          openfig((f_range_name(I)))
          hold on
          plot(temp_f(j), temp_d(j), temp_k(j), 'o',...
                   'MarkerEdgeColor','k','MarkerFaceColor', 'b', ...
                   'MarkerSize', 9)
          savefig(['MI_' num2str(f_range(I)) 'Hz.fig'])
          close all
      end

[Stephen23]

This is a pointlessly complex way to define a cell array:

f_range_name = [ {'MI_.5Hz.fig'}, {'MI_.525.fig'}, {'MI_.55.fig'}, {'MI_.575.fig'}, {'MI_.6.fig'}];

Simpler:

f_range_name = {'MI_.5Hz.fig', 'MI_.525.fig', 'MI_.55.fig', 'MI_.575.fig', 'MI_.6.fig'};

Answer 1

[Stephen23]

You used the wrong indexing for the cell array. You need to use curly braces:

openfig((f_range_name{I}))
                     ^ ^ curly braces to access the contents of a cell array!

The difference is simple:

• {} curly braces access the cell contents.
• () parentheses access the cells themselves.

https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-cell-array.html