移调阵列 [英] Transposing arrays

问题描述

我用下面的code在CSV文件中读取：

I am using the following code to read in a CSV file:

  String next[] = {};
  List<String[]> dataArray = new ArrayList<String[]>();

  try {
      CSVReader reader = new CSVReader(new InputStreamReader(getAssets().open("inputFile.csv")));
      for(;;) {
          next = reader.readNext();
          if(next != null) {
              dataArray.add(next);
          } else {
              break;
          }
      }
  } catch (IOException e) {
      e.printStackTrace();
  }

这变成一个CSV文件导入阵列dataArray的。我的申请为字典类型的应用程序 - 输入数据的第一列是词语的列表，而第二列是这些词语的定义。这里是在装载的阵列的示例：

This turns a CSV file into the array 'dataArray'. My application is for a dictionary type app - the input data's first column is a list of words, and the second column is the definitions of those words. Here is an example of the array loaded in:

Term 1, Definition 1
Term 2, Definition 2
Term 3, Definition 3

为了访问字符串之一在数组中，我用下面的code：

In order to access one of the strings in the array, I use the following code:

dataArray.get(rowNumber)[columnNumber]

然而，我需要能够生成所有术语的列表，以便它们可以被显示为字典应用。据我了解，自己访问的列是一个更加漫长的过程不是访问行（我来自一个MATLAB的背景下，这哪里会是简单）。

However, I need to be able to generate a list of all the terms, so that they can be displayed for the dictionary application. As I understand it, accessing the columns by themselves is a much more lengthy process than accessing the rows (I come from a MATLAB background, where this would be simple).

看来，为了要我输入数据的任何行随时访问，我会过得更好移调数据，并以这种方式阅读它;即：

It seems that in order to have ready access to any row of my input data, I would be better off transposing the data and reading it in that way; i.e.:

Term 1, Term 2, Term3
Definition 1, Definition 2, Definition 3

当然，我可以只提供在第一位置调换一个CSV文件 - 但Excel或OO计算器不允许超过256行，我的字典包含约2000项

Of course, I could just provide a CSV file that is transposed in the first place - but Excel or OO Calc don't allow more than 256 rows, and my dictionary contains around 2000 terms.

以下任何解决方案将受到欢迎：

Any of the following solutions would be welcomed:

• 一旦被读取到转数组的方式


• 一个改变到code上面贴，使得它在数据中的换位的方式读


• 一个简单的方法来读取阵列的整列作为一个整体

推荐答案

您可能会得到更好的利用地图数据结构（如的 HashMap的）：

You would probably be better served by using a Map data structure (e.g. HashMap):

String next[] = {};
HashMap<String, String> dataMap = new HashMap<String, String>();

try {
    CSVReader reader = new CSVReader(new InputStreamReader(getAssets().open("inputFile.csv")));
    for(;;) {
        next = reader.readNext();
        if(next != null) {
            dataMap.put(next[0], next[1]);
        } else {
            break;
        }
    }
} catch (IOException e) {
    e.printStackTrace();
}

然后你可以通过

dataMap.keySet();

和

dataMap.values();

请注意一个假设的位置：您输入数据的第一列是所有唯一值（也就是，有没有在期限列中重复的值）

Note one assumption here: that the first column of your input data is all unique values (that is, there are not repeated values in the "Term" column).

要能够访问密钥（计算）为一个数组，你可以简单地做如下：

To be able to access the keys (terms) as an array, you can simply do as follows:

String[] terms = new String[dataMap.keySet().size()];
terms = dataMap.keySet().toArray(terms);

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