How to Convert a column with Char in Cell matrice to Number?

Question

Vyshakh Pv 2019-4-16

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/456633-how-to-convert-a-column-with-char-in-cell-matrice-to-number

评论： Vyshakh Pv 2019-5-5

采纳的回答： Stephen23

在 MATLAB Online 中打开

I have a cell array:

A =

'Time'    'Name'    'Location'    'Duration'    'Remarks'
'100'    'John'        'Abc'        '1000'      'Nill'
'101'    'Tim'         'Def'        '1000'      'Nill'
'102'    'Tom'         'Ghi'        '2000'      'Nill'
'103'    'Jim'         'Jkl'        '4500'      'Nill'

Here I want to convert A(2:4, 1), and A(2:4, 4) to numbers and save to same matrice A.

I can do this using a LOOP and STR2DOUBLE(), but it is very time consuming when the matrice is very large.

Is there any method to convert a range of char-values in a cell matrice to to numbers?

I am looking for someting like:

A(2:4,  1) = str2double( A(2:4,  1) )      %This command is not working
A(2:4,  4) = str2double( A(2:4,  4) )      %This command is not working

Output should look like:

A =

'Time'    'Name'    'Location'    'Duration'    'Remarks'
    'John'        'Abc'        1000          'Nill'
    'Tim'         'Def'        1000          'Nill'
    'Tom'         'Ghi'        2000          'Nill'
    'Jim'         'Jkl'        4500          'Nill'

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

Stephen23 2019-4-16

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/456633-how-to-convert-a-column-with-char-in-cell-matrice-to-number#answer_370830

编辑：Stephen23 2019-4-16

在 MATLAB Online 中打开

You almost got it right, you just need to split the numeric array into a cell array so that it can be allocated back to the cell array A:

A(2:4,1) = num2cell(str2double(A(2:4,1))) 
A(2:4,4) = num2cell(str2double(A(2:4,4)))

Or simply on one line:

A(2:4,[1,4]) = num2cell(str2double(A(2:4,[1,4])))

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Vyshakh Pv 2019-5-5

在 MATLAB Online 中打开

actually.....

for i = first : last
    mat{i, col} = str2double(mat{i, col});
end

is faster than ....

mat(first:end, col) = num2cell(str2double(mat(first:end, col)));

请先登录，再进行评论。

Answer 2

KSSV 2019-4-16

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/456633-how-to-convert-a-column-with-char-in-cell-matrice-to-number#answer_370829

编辑：KSSV 2019-4-16

在 MATLAB Online 中打开

A = {'Time'    'Name'    'Location'    'Duration'    'Remarks'
'100'    'John'        'Abc'        '1000'      'Nill'
'101'    'Tim'         'Def'        '1000'      'Nill'
'102'    'Tom'         'Ghi'        '2000'      'Nill'
'103'    'Jim'         'Jkl'        '4500'      'Nill'}  ;
T = cell2table(A(2:end,:),'VariableNames',A(1,:)) ; 
T.(1) = cell2mat(T.(1)) ; 
T.(4) = cell2mat(T.(4)) ;
T