使用MATLAB从xml文件中提取数据

Question

我是一个完整的编程初学者，正在尝试学习MATLAB。我想从一堆不同的xml文件中提取数值数据。数字数据项由标签和边界限定。如何在MATLAB中编写程序？

我的算法：

1. Open the folder
2. Look into each of 50 xml files, one at a time
3. Where the tag <HNB.1></HNB.1> exists, copy numerical contents between said tag and write results into a new file
4. The new file name given for step 3 should be the same as the initial file name read in Step 2, being appended with "_data extracted"

示例：

FileName = Stewart.xml
Contents = blah blah blah <HNB.1>2</HNB.1> blah blah
NewFileName = Stewart_data extracted.txt
Contents = 2

Answer 1

MATLAB中读取xml数据的基本功能是xmlread;但如果你是一个完全的初学者，那么使用它可能会很棘手。试试this series of blog postings，向您展示如何将它们放在一起。

Answer 2

假设您要阅读此文件：

<PositiveSamples numImages="14">
<image numSubRegions="2" filename="TestingScene.jpg">
	<subregion yStart="213" yEnd="683" xStart="1" xEnd="236"/>
	<subregion yStart="196" yEnd="518" xStart="65" xEnd="226"/>
</image>
</PositiveSamples>

然后在matlab中，按如下方式读取文件内容：

%read xml file
xmlDoc = xmlread('PositiveSamples.xml');

%Get root element
root = xmlDoc.getDocumentElement();

%Read attributevale
numOfImages = root.getAttribute('numImages');
numOfImages = char(numOfImages);   
numOfImages = uint16(eval(numOfImages));