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preview

Subset of data in datastore

Syntax

data = preview(ds)

Description

example

data = preview(ds) returns a subset of data from datastore ds without changing its current position.

Examples

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Create a datastore from the sample file, airlinesmall.csv, which contains tabular data.

ds = tabularTextDatastore('airlinesmall.csv','TreatAsMissing','NA');

Modify the SelectedVariableNames property to specify the variables of interest.

ds.SelectedVariableNames = {'DepTime','ArrTime','ActualElapsedTime'};

Preview the data for the selected variables.

data = preview(ds)
data=8×3 table
    DepTime    ArrTime    ActualElapsedTime
    _______    _______    _________________

      642        735              53       
     1021       1124              63       
     2055       2218              83       
     1332       1431              59       
      629        746              77       
     1446       1547              61       
      928       1052              84       
      859       1134             155       

Create a datastore from the sample file, mapredout.mat, which is the output file of the mapreduce function.

ds = datastore('mapredout.mat');

Preview the data in the datastore.

data = preview(ds)
data=1×2 table
    Key      Value 
    ____    _______

    'AA'    [14930]

Input Arguments

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Input datastore. You can use the datastore function to create a datastore object from your data.

Output Arguments

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Subset of data, returned as a table or an array of integers.

Type of datastoreDescription
TabularTextDatastore and SpreadsheetDatastoreTable with variables specified by the SelectedVariableNames property. The table contains at most eight rows.
ImageDatastoreArray of integers corresponding to the first image.
KeyValueDatastoreTable with the variables Key and Value.
FileDatastoreTable containing the output returned by the read function, specified by the 'ReadFcn' parameter in the fileDatastore function.

See Also

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Introduced in R2014b