Matlab：将文本文件读入矩阵

Question

我想在 Matlab 中从文本文件中读取数据。该文件描述了一个表面由两部分组成： 1) 包含 x、y 尺寸（以像素和 nm 为单位）等信息的标题。 2）高度值矩阵（512x512）

当我首先尝试仅读取矩阵时，我最终得到的是单列向量而不是矩阵 C = textscan(id,'%f','HeaderLines',18,'Delimiter','\t') 该文件包含“”分隔值和分隔矩阵行的行。当我手动删除标题并阅读它时，它可以工作 A=dlmread(path,'\t',[0 0 511 511]);

我想用 textscan 获得相同的 512x512 矩阵，以便我以后也可以解析标题 - 我该怎么做？

Answer 1

如果您没有严格绑定到textscan，则可以改用fscanf（请参阅docs）。像这样：

fid = fopen('FileName.txt');

% here you have to skip (or parse) your header lines
% and determine number of rows/columns in your data matrix

A = fscanf(fid, '%g', [NColumns NRows]);
fclose(fid);

% Transpose so that A matches
% the orientation of the file
A = A';

更新1

此代码可能不是很优雅，但它会将您的标头解析为 FileInfo 结构，因此您可以稍后在代码中使用这些数据。

% sample file header
%
% # File Format = ASCII
% # Created by SPIP 6.2.8.0 2014-08-15 20:41
% # Original file: D:\...
% # x-pixels = 512
% # y-pixels = 512
% # x-length = 319375
% # y-length = 319375
% # x-offset = 0
% # y-offset = 0
% # z-unit = [nm]
% # scanspeed = 638.75
% # forcecurve = 0
% # voidpixels =76
% # description =62:Confocal Height Image  Date: 2013-08-20T13:36 User: Unknown
% # Start of Data: MATRIX

fid = fopen('text.txt','r');

FileInfo  = [];
tmpString = '';   % initializing the s
while isempty(strfind(tmpString,'Start of Data: MATRIX'))

    % we read a string from file
    tmpString = fgetl(fid);
    % and split it into left and right parts according to the '=' position
    [kev,val] = strtok( tmpString(3:end) , ':=' );

    % remove spaces from key name and make it a valid variable name in MatLab
    keyName = genvarname( strrep(strrep(kev,'-',''),' ','') );

    % check if key value is a number
    [x,OK]    = str2num(strtrim(val(2:end)));

    % if value is a number, use it otherwise leave the trimmed original string
    if OK
        FileInfo.(keyName) = x;
    else
        FileInfo.(keyName) = strtrim(val(2:end));
    end

end

% Now we can read the data
A = fscanf(fid, '%g', [FileInfo.xpixels FileInfo.ypixels]);
fclose(fid);

% Transpose so that A matches
% the orientation of the file
%A = A';