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    %% Create a Dataset Array from a Numeric Array  
% This example shows how to create a dataset array from a numeric array
% existing in the MATLAB(R) workspace.   

%% Load sample data. 
load fisheriris

%%
% Two variables load into the workspace: |meas|, a 150-by-4 numeric array,
% and |species|, a 150-by-1 cell array of species labels.  

%% Create a dataset array. 
% Use |mat2dataset| to convert the numeric array, |meas|, into a dataset array. 
ds = mat2dataset(meas);
ds(1:10,:) 

%%
% The array, |meas|, has four columns, so the dataset array, |ds|, has four
% variables. The default variable names are the array name, |meas|, with
% column numbers appended. 

%%
% You can specify your own variable or observation names using the name-value
% pair arguments |VarNames| and |ObsNames|, respectively. 

%%
% If you use |dataset| to convert a numeric array to a dataset array, by
% default, the resulting dataset array has one variable that is an array
% instead of separate variables for each column.  

%% Examine the dataset array. 
% Return the size of the dataset array, |ds|. 
size(ds) 

%%
% The dataset array, |ds|, is the same size as the numeric array, |meas|.
% Variable names and observation names do not factor into the size of a
% dataset array.  

%% Explore dataset array metadata. 
% Return the metadata properties of the dataset array, |ds|. 
ds.Properties 

%%
% You can also access the properties individually. For example, you can
% retrieve the variable names using |ds.Properties.VarNames|.  

%% Access data in a dataset array variable. 
% You can use variable names with dot indexing to access the data in a dataset
% array. For example, find the minimum value in the first variable, |meas1|. 
min(ds.meas1)  

%% Change variable names. 
% The four variables in |ds| are actually measurements of sepal length,
% sepal width, petal length, and petal width. Modify the variable names
% to be more descriptive. 
ds.Properties.VarNames = {'SLength','SWidth','PLength','PWidth'};  

%% Add description. 
% you can add a description for the dataset array. 
ds.Properties.Description = 'Fisher iris data';
ds.Properties 

%%
% The dataset array properties are updated with the new variable names and
% description.  

%% Add a variable to the dataset array. 
% The variable |species| is a cell array of species labels.
% Add |species| to the dataset array, |ds|, as a nominal array named |Species|.
% Display the first five observations in the dataset array. 
ds.Species = nominal(species);
ds(1:5,:) 

%%
% The dataset array, |ds|, now has the fifth variable, |Species|.