Word Cloud (词云) - Matlab

今天要总结的是 Word Cloud 最后一个部分了，用 Matlab 来建立 word cloud。Matlab R2018b 已经提供 wordcloud 函数能够直接生成词云了。

>> Create Word Cloud via Matlab

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1) 准备文本。

很少说了，懒人继续用上次那个 Word Cloud History.txt 的文本吧。

2) 读取并清洗数据文本。

%read txt as a string
text = string(fileread('C:\Users\yuki\Desktop\WordCloudHistory.txt'));
%delete puchuation
punctuationCharacters = ["." "?" "!" "," ";" ":"];
text = replace(text,punctuationCharacters," ");
%convert a string to array
words = split(join(text));
%delete the words has less than 5 characters, which are problely stop words
words(strlength(words)<5) = [];
%change all words to lowercase
words = lower(words);

3) 计算词频并生成数组。

%calculate the frequencies for every word
[numOccurrences,uniqueWords] = histcounts(categorical(words));

4) 生成 word cloud。

figure
%set properties for word cloud
wordcloud(uniqueWords,numOccurrences,'Shape', "rectangle", 'MaxDisplayWords', 200);
title("Word Cloud History")

>> Notes

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1) Matlab 也有插件能够直接生成词云，操做简单，不用编程，哈哈。

2) 既然已经说了各类能够建立词云的方法，那么就顺便总结一下什么方法好用方便不花钱。

Tool		Easy Use		Free		Need Script
Python		Clear document, powerful text mining library		Yes		Yes
JavaScript		Need to extract array by own, and need to find a way to save the image		Yes		Yes
R		Clear document, powerful text mining library		Yes		Yes
Matlab		Clear document, interactive interface		No		Optional

>> Sample Code

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download here

>> Related Blogs

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1. Word Cloud (词云) - Python
2. Word Cloud (词云) - JavaScript
3. Word Cloud (词云) - R