Question

我已经查看了here和here，但我不确定是否找到了我需要的内容。

我有一个看起来像

的不规则文件（代表粒子1到5的邻居）

我想弄清楚加载它的方式（作为＆＃39;称为A的东西）并执行以下操作：

计算一行上的元素数量（例如size(A(1,:))应该给我3）
给定数组B（大小为5），选择与行给出的索引相对应的B元素（B(A(1,:))之类的内容会给我[B(2) B(3) B(5)]）

Answer 1

Since you want arrays with size depending on their first index, you're probably left with cells. Your cell A could be such that A{1} equals to [2 3 5] and A{2} to [1 3] in your example etc. To do this you can read your file infile by

fid=fopen(infile,'rt');
A=[];
while 1
    nextline=fgets(fid);
    if nextline==-1 %EOF reached
        break;
    end
    A{end+1}=sscanf(nextline,'%d');
end
fclose(fid);

%demonstrate use for indexing
B=randi(10,5,1);
B(A{3}) %2-element vector
B(A{4}) %empty vector

Then A{i} is a vector corresponding to the ith line in your file. If the line is empty, then it's the empty vector. You can use it to index B as you want to, see the example above. Note that you should not add a newline at the very end of your infile, otherwise you'll have a spurious empty element for A. If you know in advance how many lines you need to read, this is not an issue.

And the number of entries in line i are given by length(A{i}), with i=1:length(A).

Matlab，加载邻接列表（不规则文件）

1 个答案: