Analyze Text Data with String Arrays
This example shows how to store text from a file as a string array, sort the words by their frequency,
plot the result, and collect basic statistics for the words found in the file.
Import Text File to String Array
Read text from Shakespeare's Sonnets with the fileread function. fileread returns the text as a
1-by-100266 character vector.
sonnets = fileread('sonnets.txt');
sonnets(1:35)
ans =
'THE SONNETS
by William Shakespeare'
Convert the text to a string using the string function. Then, split it on newline characters using the
splitlines function. sonnets becomes a 2625-by-1 string array, where each string contains one
line from the poems. Display the first five lines of sonnets.
sonnets = string(sonnets);
sonnets = splitlines(sonnets);
sonnets(1:5)
ans = 5x1 string
"THE SONNETS"
""
"by William Shakespeare"
""
""
Clean String Array
To calculate the frequency of the words in sonnets, first clean it by removing empty strings and
punctuation marks. Then reshape it into a string array that contains individual words as elements.
Remove the strings with zero characters ("") from the string array. Compare each element of
sonnets to "", the empty string. Starting in R2017a, you can create strings, including an empty
string, using double quotes. TF is a logical vector that contains a true value wherever sonnets
contains a string with zero characters. Index into sonnets with TF and delete all strings with zero
characters.
TF = (sonnets == "");
sonnets(TF) = [];
sonnets(1:10)
ans = 10x1 string
"THE SONNETS"
"by William Shakespeare"
" I"
" From fairest creatures we desire increase,"
" That thereby beauty's rose might never die,"
" But as the riper should by time decease,"
Analyze Text Data with String Arrays
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