create empty row inside a vector

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Alberto Acri 2023-7-18

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1997313-create-empty-row-inside-a-vector

评论： Alberto Acri 2023-7-18

采纳的回答： Chunru

value_GS_test.mat

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Hi. I need to analyze the rows of the vector 'value_GS_test' and transform only the numbers 254 and 255 (if any) into '[]' while keeping the same number of rows as in the original vector. Here is an example:

Right now I am using this code, but it only deletes one row (at 255) for me. How can I get the desired result?

value_GS = importdata("value_GS_test.mat");  % 6 elements
for rows_value_GS = 1 %:height(value_GS)
    
    analysis_number = value_GS(rows_value_GS);
    
    if analysis_number == 255 
    
        value_GS(rows_value_GS) = [];
    elseif analysis_number == 254 
    
        value_GS(rows_value_GS) = [];
    
    else
        value_GS(rows_value_GS) = value_GS(rows_value_GS);
            
    end
end

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Simon Chan 2023-7-18

What is the final purpose of making a bracket to those positions? For display only? Or you will write it as blank on a text file?

Alberto Acri 2023-7-18

For display

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采纳的回答

Chunru 2023-7-18

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1997313-create-empty-row-inside-a-vector#answer_1274843

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load(websave("value_GS_test.mat", "https://www.mathworks.com/matlabcentral/answers/uploaded_files/1436593/value_GS_test.mat"));
value_GS = double(value_GS)
value_GS = 6×1
   255
   255
   255
    68
    70
    72
value_GS(value_GS>=254) = nan;
value_GS
value_GS = 6×1
   NaN
   NaN
   NaN
    68
    70
    72

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Dyuman Joshi 2023-7-18

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Yes, it is.

Refer to @Walter Roberson's comment above - "Note however that uint8 cannot represent NaN or inf".

When you try to assign NaN (or Inf for that matter) to a uint8 (or any integer data type) array, it will display 0 instead of NaN

%Signed integer data type example - 
y = int16(1:4)
y = 1×4
   1   2   3   4
%Assinging 2nd element of the vector to be NaN
y(2) = NaN 
y = 1×4
   1   0   3   4
%Unsigned integer data type example -
%Initializing NaN with an unsigned integer leads to 0 as well
z = uint8([1 23 NaN 19 5])
z = 1×5
    1   23    0   19    5