How can I load a .mat struct?

Question

David Ruiz Velasco 2021-6-26

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/865945-how-can-i-load-a-mat-struct

评论： David Ruiz Velasco 2021-6-29

Hello community:

I use Matlab 2021a and when I try to load a .mat struct with these sentences load('linesStruct_1.mat') or load('linesStruct_1') I receive the following message:

Error using load

Unable to read MAT-file C:\ ... linesStruct_1.mat. Not a binary MAT-file. Try load -ASCII to

read as text.

Error in drawpoint_Algoritmo_Rename_Struct_Pendiente (line 5)

load('linesStruct_1.mat');

Could it be because I have saved the structures with a different name (lines in place of linesStruct_1.mat) than the image? Or maybe it has to do with the shortcut icons that appear in my folders?.

I remember this was not happening in other versions. I have been reading the many cases in which this occurs but I can not find a solution according to my situation. Any idea?

Thank you very much.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2021-6-26

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/865945-how-can-i-load-a-mat-struct#answer_734220

在 MATLAB Online 中打开

The file is not a .mat file. At the moment we do not know what it is. Experiment with

filename = 'linesStruct_1.mat';
if isunix()
  filename = 'handel.mat';
end
[fid, msg] = fopen(filename, 'r');
if fid < 0
   error('could not open file "%s" because "%s"', filename, msg);
end
bytes = fread(fid, [1 100], '*uint8');
fclose(fid)
ans = 0
fprintf('first part of file as text:\n');
first part of file as text:
fprintf('%s\n', char(bytes));
MATLAB 5.0 MAT-file, Platform: GLNX86, Created on: Tue Mar  9 11:01:23 2004                         
fprintf('\nas decimal: \n');
as decimal: 
disp(bytes);
  Columns 1 through 33

    77    65    84    76    65    66    32    53    46    48    32    77    65    84    45   102   105   108   101    44    32    80   108    97   116   102   111   114   109    58    32    71    76

  Columns 34 through 66

    78    88    56    54    44    32    67   114   101    97   116   101   100    32   111   110    58    32    84   117   101    32    77    97   114    32    32    57    32    49    49    58    48

  Columns 67 through 99

    49    58    50    51    32    50    48    48    52    32    32    32    32    32    32    32    32    32    32    32    32    32    32    32    32    32    32    32    32    32    32    32    32

  Column 100

    32
fprintf('\nas hex: \n');
as hex: 
fprintf('%02x ', bytes);
4d 41 54 4c 41 42 20 35 2e 30 20 4d 41 54 2d 66 69 6c 65 2c 20 50 6c 61 74 66 6f 72 6d 3a 20 47 4c 4e 58 38 36 2c 20 43 72 65 61 74 65 64 20 6f 6e 3a 20 54 75 65 20 4d 61 72 20 20 39 20 31 31 3a 30 31 3a 32 33 20 32 30 30 34 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 
fprintf('\n');

The bit about isunix() is my substituting a different file for the purpose of demonstration here.

You are hoping to see the text version start with 'MATLAB 5.0' or 'MATLAB 7.3' . If you show us the three parts of the output we might be able to tell you what kind of file you actually have instead of a .mat file.

7 个评论
显示 5更早的评论隐藏 5更早的评论

David Ruiz Velasco 2021-6-26

在 MATLAB Online 中打开

Hello again.

I show you the results obtained. I include the code with I saved the files. I apologize for not respecting the correct setting of the live script.

Name = sprintf("linesStruct_%i.mat", i);

Thanks in advance.

filename = 'linesStruct_1.mat';
if isunix()
  filename = 'handel.mat';
end
[fid, msg] = fopen(filename, 'r');
if fid < 0
   error('could not open file "%s" because "%s"', filename, msg);
end
bytes = fread(fid, [1 100], '*uint8');
fclose(fid)

ans = 0

fprintf('first part of file as text:\n');
first part of file as text:
fprintf('%s\n', char(bytes));

ÿØÿà JFIF ÿÛ

$.' ",#(7),01444'9=82<.342ÿÀ

fprintf('\nas decimal: \n');

as decimal:

disp(bytes);

Columns 1 through 32

255 216 255 224 0 16 74 70 73 70 0 1 1 0 0 1 0 1 0 0 255 219

0 67 0 8 6 6 7 6 5 8

Columns 33 through 64

7 7 7 9 9 8 10 12 20 13 12 11 11 12 25 18 19 15 20 29 26 31 30

29 26 28 28 32 36 46 39 32

Columns 65 through 96

34 44 35 28 28 40 55 41 44 48 49 52 52 52 31 39 57 61 56 50 60 46

51 52 50 255 192 0 11 8 1 0

Columns 97 through 100

1 0 1 1

fprintf('\nas hex: \n');

as hex:

fprintf('%02x ', bytes);

ff d8 ff e0 00 10 4a 46 49 46 00 01 01 00 00 01 00 01 00 00 ff db 00 43 00 08 06 06 07 06 05 08 07 07 07 09 09 08 0a 0c 14 0d 0c 0b 0b 0c 19 12 13 0f 14 1d 1a 1f 1e 1d 1a 1c 1c 20 24 2e 27 20 22 2c 23 1c 1c 28 37 29 2c 30 31 34 34 34 1f 27 39 3d 38 32 3c 2e 33 34 32 ff c0 00 0b 08 01 00 01 00 01 01

fprintf('\n');

David Ruiz Velasco 2021-6-27

编辑：David Ruiz Velasco 2021-6-27

在 MATLAB Online 中打开

Hello.

I think I have found the solution in this post:

https://es.mathworks.com/matlabcentral/answers/177752-how-do-i-open-my-matlab-figures.

I have been reading about the difference between images and figures. If I take account the used code, I should use saveas or savefig only after modifying the code. However, I understand that keyboard command will still be a problem.

I will keep working on this.

Thank you very much.

clear;
clc;
c=cell(10,1);
for i=1:1
    
    c{i}=imread(sprintf('Mexico_Resize_%d.jpg',i));
    columns = 256; rows = 256;
    
    I1 = c{i};
    imshow(I1);
    
    hold on
    I1 = imresize(I1, [columns rows]);
    
    x1 = 64; y1 = 64; x2 = 64; y2 = 128; x3 = 64; y3 = 192;
    x4 = 192; y4 = 64; x5 = 192; y5 = 128; x6 = 192; y6 = 192;
    
    roi1= drawpoint('Position', [x1, y1], 'Color','b');
    event.listener(roi1, 'ROIMoved', @allevents_1);
    roi2= drawpoint('Position', [x2, y2], 'Color','g');
    event.listener(roi2, 'ROIMoved', @allevents_2);
    roi3= drawpoint('Position', [x3, y3], 'Color','w');
    event.listener(roi3, 'ROIMoved', @allevents_3);
    roi4= drawpoint('Position', [x4, y4], 'Color','c');
    event.listener(roi4, 'ROIMoved', @allevents_4);
    roi5= drawpoint('Position', [x5, y5], 'Color','r');
    event.listener(roi5, 'ROIMoved', @allevents_5);
    roi6= drawpoint('Position', [x6, y6], 'Color','m');
    event.listener(roi6, 'ROIMoved', @allevents_6);
    
    % Stop at each iteration to move the points:  
    keyboard;
    
    dataA(1,1) = roi1.Position(1,1); dataA(1,2) = roi1.Position(1,2); 
    dataA(2,1) = roi2.Position(1,1); dataA(2,2) = roi2.Position(1,2);
    dataB(1,1) = roi2.Position(1,1); dataB(1,2) = roi2.Position(1,2); 
    dataB(2,1) = roi3.Position(1,1); dataB(2,2) = roi3.Position(1,2);
    dataC(1,1) = roi4.Position(1,1); dataC(1,2) = roi4.Position(1,2); 
    dataC(2,1) = roi5.Position(1,1); dataC(2,2) = roi5.Position(1,2);
    dataD(1,1) = roi5.Position(1,1); dataD(1,2) = roi5.Position(1,2); 
    dataD(2,1) = roi6.Position(1,1); dataD(2,2) = roi6.Position(1,2);
    
    plot(dataA(:, 1), dataA(:, 2), 'LineWidth',2,'Color','green');
    plot(dataB(:, 1), dataB(:, 2), 'LineWidth',2,'Color','green');
    plot(dataC(:, 1), dataC(:, 2), 'LineWidth',2,'Color','green');
    plot(dataD(:, 1), dataD(:, 2), 'LineWidth',2,'Color','green');
    
    pendienteA = (dataA(2,2) - dataA(1,2))/(dataA(2,1) - dataA(1,1)); 
    pendienteB = (dataB(2,2) - dataB(1,2))/(dataB(2,1) - dataB(1,1)); 
    pendienteC = (dataC(2,2) - dataC(1,2))/(dataC(2,1) - dataC(1,1)); 
    pendienteD = (dataD(2,2) - dataD(1,2))/(dataD(2,1) - dataD(1,1)); 
    
    lines(1).point1 = [dataA(1,1), dataA(1,2)]; lines(1).point2 = [dataA(2,1),dataA(2,2)];
    lines(2).point1 = [dataB(1,1), dataB(1,2)]; lines(2).point2 = [dataB(2,1),dataB(2,2)];
    lines(3).point1 = [dataC(1,1), dataC(1,2)]; lines(3).point2 = [dataC(2,1),dataC(2,2)];
    lines(4).point1 = [dataD(1,1), dataD(1,2)]; lines(4).point2 = [dataD(2,1),dataD(2,2)];
   
    lines(1).pendiente = pendienteA;
    lines(2).pendiente = pendienteB;
    lines(3).pendiente = pendienteC;
    lines(4).pendiente = pendienteD;
    
    dim = I1(1:256, 1:256);
    
    Name = sprintf("linesStruct_%i.mat", i);
    CutOut = I1(1:256, 1:256);
    imwrite(CutOut, Name, 'jpg'); % This is not correct. 
    
    keyboard;   
    imshow(CutOut);
    
    close all
    
end

Walter Roberson 2021-6-29

I am not clear as to whether the problem is solved?

David Ruiz Velasco 2021-6-29

Hello.

Yes, it is solved.

Thank you very much.

请先登录，再进行评论。

How can I load a .mat struct?

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

采纳的回答

7 个评论
显示 5更早的评论隐藏 5更早的评论

更多回答（0 个）

另请参阅

类别

标签

产品

版本

Community Treasure Hunt

How can I load a .mat struct?

0 个评论 显示 -2更早的评论隐藏 -2更早的评论

采纳的回答

7 个评论 显示 5更早的评论隐藏 5更早的评论

更多回答（0 个）

另请参阅

类别

标签

产品

版本

Community Treasure Hunt

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

7 个评论
显示 5更早的评论隐藏 5更早的评论