How can I make this matrix ?

Question

Sourasis Chattopadhyay 2022-12-13

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1877357-how-can-i-make-this-matrix

评论： Voss 2022-12-14

采纳的回答： Voss

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Answer 1

Voss 2022-12-13

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https://ww2.mathworks.cn/matlabcentral/answers/1877357-how-can-i-make-this-matrix#answer_1127092

在 MATLAB Online 中打开

% your matrix:
i = 0; m  = 1; j = 2; n = 3;
M = repmat([i i i m m j j j n n],4,1)
M = 4×10
     0     0     0     1     1     2     2     2     3     3
     0     0     0     1     1     2     2     2     3     3
     0     0     0     1     1     2     2     2     3     3
     0     0     0     1     1     2     2     2     3     3
% delete columns 4-5 and 9-10:
M(:,[4 5 9 10]) = []
M = 4×6
     0     0     0     2     2     2
     0     0     0     2     2     2
     0     0     0     2     2     2
     0     0     0     2     2     2

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Sourasis Chattopadhyay 2022-12-14

Because my matrix size is not fixed. But every time I need to delete two column after the equal number of column interval.

Voss 2022-12-14

在 MATLAB Online 中打开

Suppose you want to delete columns 4, 9, 14, ... and columns 5, 10, 15, ...

M = reshape(1:100,4,[])
M = 4×25
     1     5     9    13    17    21    25    29    33    37    41    45    49    53    57    61    65    69    73    77    81    85    89    93    97
     2     6    10    14    18    22    26    30    34    38    42    46    50    54    58    62    66    70    74    78    82    86    90    94    98
     3     7    11    15    19    23    27    31    35    39    43    47    51    55    59    63    67    71    75    79    83    87    91    95    99
     4     8    12    16    20    24    28    32    36    40    44    48    52    56    60    64    68    72    76    80    84    88    92    96   100
spacing = 5;
N_Cols = size(M,2);
col_to_delete = [4:spacing:N_Cols 5:spacing:N_Cols];
M(:,col_to_delete) = []
M = 4×15
     1     5     9    21    25    29    41    45    49    61    65    69    81    85    89
     2     6    10    22    26    30    42    46    50    62    66    70    82    86    90
     3     7    11    23    27    31    43    47    51    63    67    71    83    87    91
     4     8    12    24    28    32    44    48    52    64    68    72    84    88    92