如何在MATLAB中加载这种矩阵 [英] How to load this kind of matrix in MATLAB

问题描述

我有一个上三角矩阵，如：

  A =负载（ 'A.TXT'）; 
 
 1.0 3.32 -7.23 
 1.00 0.60 
 
  

我想加载它在MATLAB中，因为这是对称转换它做
$ b $ p $ c $ a = A + triu（A，1）'

所以最后我会有一个矩阵 a

  1.0 3.32 -7.23 
 3.32 1.00 0.60 
 -7.23 0.60 1.00 
  

我现在遇到的问题是在加载时：

 >> A = load（'A.txt'）; 
？错误使用==>加载
 ASCII文件第一行的列数C：\ A.txt 
必须与前面的行相同。 
  

有没有办法达到这个效果？

解决方案

请尝试使用 importdata 相反，加载通常只用于 .mat em>文件。你的文件 A.txt 结构如何？如果是这样，

  1.0 3.32 -7.23 
 1.00 0.60 
 1.00 
  

然后您将获得

  A = importdata（'A.txt'）
 
 A = 
 
 1.0000 3.3200 -7.2300 
 1.0000 0.6000 
 1.0000 NaN NaN 
  

所以你必须移动最后两行，像这样

$ b $（$，$ $ $ $ $ $ $ $ $ $ $ $ $ $ $） 3，：），[0 2]）

A =

1.0000 3.3200 -7.2300
NaN 1.0000 0.6000
NaN NaN 1.0000

然后用0替换NaNs并使用您的表达式来创建对称矩阵。

  A（isnan（A））= 0; 
 
 a = A + triu（A，1）'; 
 
 A = 
 
 1.0000 3.3200 -7.2300 
 3.3200 1.0000 0.6000 $ b $ -7.2300 0.6000 1.0000 
  pre> 
I have an upper triangular matrix like:
A=  load('A.txt');

1.0    3.32   -7.23
       1.00    0.60
               1.00
I want to load it in MATLAB, and as this is symmetric converting it doing  

a = A + triu(A, 1)'

 so at the end I will have a matrix a
1.0    3.32   -7.23
3.32   1.00    0.60
-7.23  0.60    1.00
the problem I am having is at the moment of loading:
>> A = load('A.txt');
??? Error using ==> load
Number of columns on line 1 of ASCII file C:\A.txt
must be the same as previous lines.
Is there a way to accomplish this?
解决方案
Try using importdata instead, load is usually only used for .mat files. How is your file A.txt structured? If it is like this,
1.0    3.32   -7.23
1.00    0.60
1.00
then you will get
A = importdata('A.txt')

A =

    1.0000    3.3200   -7.2300
    1.0000    0.6000       NaN
    1.0000       NaN       NaN
So you will have to shift the two last rows, like this
A(2,:) = circshift(A(2,:),[0 1])
A(3,:) = circshift(A(3,:),[0 2])

A =

    1.0000    3.3200   -7.2300
    NaN       1.0000    0.6000
    NaN       NaN       1.0000
and then replace the NaNs with 0s and use your expression to create a symmetric matrix.
A(isnan(A)) = 0;

a = A + triu(A, 1)';

A =

    1.0000    3.3200   -7.2300
    3.3200    1.0000    0.6000
   -7.2300    0.6000    1.0000


                        
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