MATLAB Programming Fundamentals - MathWorks

Clean Messy and Missing Data in Tables

This example shows how to find, clean, and delete table rows with missing data.

Load Sample Data

Load sample data from a comma-separated text file, messy.csv. The file contains many

different missing data indicators:

• Empty character vector ('')


• period (.)


• NA


• NaN


• -99

To specify the character vectors to treat as empty values, use the 'TreatAsEmpty'

name-value pair argument with the readtable function. (Use the disp function to

display all 21 rows, even when running this example as a live script.)

T = readtable('messy.csv','TreatAsEmpty',{'.','NA'});

disp(T)

A B C D E

______ ____ _____ ____ ____

'afe1' 3 'yes' 3 3

'egh3' NaN 'no' 7 7

'wth4' 3 'yes' 3 3

'atn2' 23 'no' 23 23

'arg1' 5 'yes' 5 5

'jre3' 34.6 'yes' 34.6 34.6

'wen9' 234 'yes' 234 234

'ple2' 2 'no' 2 2

'dbo8' 5 'no' 5 5

'oii4' 5 'yes' 5 5

'wnk3' 245 'yes' 245 245

'abk6' 563 '' 563 563

'pnj5' 463 'no' 463 463

'wnn3' 6 'no' 6 6

'oks9' 23 'yes' 23 23

'wba3' NaN 'yes' NaN 14

'pkn4' 2 'no' 2 2

Clean Messy and Missing Data in Tables