clear
%% xlsread
         [NumVar,txtVar,raw]=xlsread('crabs')
         FullColumnNames=txtVar(1,1:7)  % all nominal initial data
         NamesProperties=FullColumnNames
         NamesProperties(2:3)=[]               % delete names of column of {'color' 'spine condition'}
                                                                  %  xlswrite  - if you want, you can find in ML Help
%% readtable - suitable  for the following formats:
                %% .txt, .dat;   .csv - Excel  format (delimited text too)
                %% .xls, .xlsb, .xlsm, .xlsx,...  or .ods
                    tcrab=readtable('crabs.xlsx');
                                                                %writetable - see ML Help
%% The choice the part of the table
        NumDataCrabs=tcrab(:,[1,4:7])            %  'Y'    'width'    'sattelts'    'weight'    'catwidth'
       data_width= table2array(NumDataCrabs(:,2))  % the width has been selected
       md=median(data_width)
      sortedWidth=sort(data_width);
      M=length(data_width)
      if mod(M,2)==0
       OrdinaryMedianWidth=(sortedWidth(M/2)+sortedWidth(M/2+1))/2
      else
       OrdinaryMedianWidth=sortedWidth(round(M/2))
      end
 % middle element  for an odd-sized sample or the average of the two central elements for an even-sized sample
        summary(NumDataCrabs) % ~summary(NumDataCrabs,1) along rows
%% look at the result 
truefalse=istable(tcrab(1,3))                                    %Nominal Variables were represanted  as
tcrab(1,3)                                                  % Char elements of MATLAB, but they do not 
                                                                  % exist as separate elements, but only as part 
                                                                  % of the table, even for a single element 
                                                                  
%% Convert to array (numeric)
MatrixCrabs=table2array(NumDataCrabs)  
% Statistical Analysis based on Matrix, f.e.:
corrcoef(MatrixCrabs)

%% save NameMatFile var1 var2  -  as NameMatFile.mat
save DataForAnalysis NamesProperties MatrixCrabs
% NameMatFile ~ DataForAnalysis.mat
% var1 ~ NamesProperties; var2 ~ MatrixCrabs

%% check inverse operation:
    PartTableCrabs=array2table(MatrixCrabs,'VariableNames',NamesProperties)  
%_________________________Correctly__________________________________%
%% DataForAnalysis.mat this file should be located in the folder with the main program!
clear
load DataForAnalysis % see Workspace