MATLAB: Create matrix with periodic increments

matrix replication

I want to create a matrix according to this logic:
Let's say I have a base vector like [1 2 3 4 5 6]'. First I want to replicate it 4 times each time increasing by 10. So after this step I will have
[1 2 3 4 5 6 11 12 13 14 15 16 21 22 23 24 25 26 31 32 33 34 35 36 41 42 43 44 45 46]'
and then I want to take this column and replicate it 20 times (my bad I meant 19 new copies), each time increasing by 1. So the next column would be
[2 3 4 5 6 7 12 13 14 15 16 17 22 23 24 25 26 27 32 33 34 35 36 37 42 43 44 45 46 47]'
and so on
I can't find a way to do this. I want the implementation to be vectorized, I don't want to use for loops.

Best Answer

The function bsxfun is really handy for these kind of tasks:
>> X = [1;2;3;4;5;6];
>> Y = bsxfun(@plus,X,0:10:40);
>> Z = bsxfun(@plus,Y(:),0:20);
>> Z
Z =
    1    2    3    4    5    6    7    8    9   10   11   12   13   14   15   16   17   18   19   20   21
    2    3    4    5    6    7    8    9   10   11   12   13   14   15   16   17   18   19   20   21   22
    3    4    5    6    7    8    9   10   11   12   13   14   15   16   17   18   19   20   21   22   23
    4    5    6    7    8    9   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24
    5    6    7    8    9   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24   25
    6    7    8    9   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24   25   26
   11   12   13   14   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31
   12   13   14   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32
   13   14   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33
   14   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34
   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35
   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36
   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41
   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42
   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43
   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43   44
   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45
   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45   46
   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45   46   47   48   49   50   51
   32   33   34   35   36   37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52
   33   34   35   36   37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52   53
   34   35   36   37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52   53   54
   35   36   37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52   53   54   55
   36   37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52   53   54   55   56
   41   42   43   44   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61
   42   43   44   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62
   43   44   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62   63
   44   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62   63   64
   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62   63   64   65
   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62   63   64   65   66
Related Question