How can I extract an array of numbers from a text-formatted cell array of strings.

Question

dormant 2024-4-26

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2112121-how-can-i-extract-an-array-of-numbers-from-a-text-formatted-cell-array-of-strings

回答： dormant 2024-5-14

I have read some data from a spreadsheet. The values are times, but formatted with s, m or h as a suffix to indicate seconds, minutes or hours. see example below,

I'd like to convert all of them to seconds, with NaN for the blank ones.

Is there an elegant way to do this?

Like this:

    {'20s'                                        }
    {'15m'                                        }
    {0×0 char                                     }
    {'24s'                                        }
    {0×0 char                                     }
    {'44s'                                        }
    {'3h'                                         }
    {'40m'                                        }
    {'20s'                                        }
    {0×0 char                                     }
    {'14s'                                        }
    

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Answer 1

Stephen23 2024-4-26

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2112121-how-can-i-extract-an-array-of-numbers-from-a-text-formatted-cell-array-of-strings#answer_1448566

编辑：Stephen23 2024-4-26

在 MATLAB Online 中打开

C = {'20s';'15m';'';'24s';'';'44s';'3h';'40m';'20s';'';'14s'}
C = 11x1 cell array
    {'20s'   }
    {'15m'   }
    {0x0 char}
    {'24s'   }
    {0x0 char}
    {'44s'   }
    {'3h'    }
    {'40m'   }
    {'20s'   }
    {0x0 char}
    {'14s'   }
F = @(t)prod(sscanf(t,'%f'));
V = cellfun(F,regexprep(C,{'h$','m$','^$'},{' 3600',' 60','NaN'},'emptymatch'))
V = 11x1
          20
         900
         NaN
          24
         NaN
          44
       10800
        2400
          20
         NaN
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Answer 2

Voss 2024-4-26

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2112121-how-can-i-extract-an-array-of-numbers-from-a-text-formatted-cell-array-of-strings#answer_1448551

在 MATLAB Online 中打开

data = {
    '20s'
    '15m'
    ''
    '24s'
    ''
    '44s'
    '3h'
    '40m'
    '20s'
    ''
    '14s'
    };
C = regexp(data,'(\d+)([hms])','tokens','once');
idx = ~cellfun(@isempty,C);
C = vertcat(C{idx});
val = str2double(C(:,1));
[~,unit] = ismember(C(:,2),{'s','m','h'});
result = NaN(size(data));
result(idx) = val.*60.^(unit-1);
disp(result)
          20
         900
         NaN
          24
         NaN
          44
       10800
        2400
          20
         NaN
          14