Split a vector into 2 oscillating vectors?

I have a .csv file with 1M datapoints, which I've turned into a simple column vector "V". I want to turn it into 2 seperate vectors that take 5k of the data points, back and forth.

So V1 takes 1:5000, 10001:15000, 20,001:25000, etc.

V2 takes 5001:10000, 15001:20000, etc.

Is there an easy way to do this other than typing out 100 sections for each variable?

Answer 1

[Voss]

Here is a way to do it. Demonstrating with smaller vectors so as to more easily verify the result. To use it on your column vector V, change N to 1e6 and block_size to 5000.

% N = 1e6;
% block_size = 5000;
N = 140;
block_size = 5;

V = (1:N).'; % some column vector with N elements

idx = (1:block_size).'+2*(0:N/block_size/2-1)*block_size;
V1 = V(idx(:));
V2 = V(idx(:)+block_size);

display([V1 V2]);

     1     6
     2     7
     3     8
     4     9
     5    10
    11    16
    12    17
    13    18
    14    19
    15    20
    21    26
    22    27
    23    28
    24    29
    25    30
    31    36
    32    37
    33    38
    34    39
    35    40
    41    46
    42    47
    43    48
    44    49
    45    50
    51    56
    52    57
    53    58
    54    59
    55    60
    61    66
    62    67
    63    68
    64    69
    65    70
    71    76
    72    77
    73    78
    74    79
    75    80
    81    86
    82    87
    83    88
    84    89
    85    90
    91    96
    92    97
    93    98
    94    99
    95   100
   101   106
   102   107
   103   108
   104   109
   105   110
   111   116
   112   117
   113   118
   114   119
   115   120
   121   126
   122   127
   123   128
   124   129
   125   130
   131   136
   132   137
   133   138
   134   139
   135   140

Answer 2

[David Hill]

v1=zeros(1,500000);
v2=zeros(1,500000);
for k=1:100
  v1((k-1)*5000+1:k*5000)=v((2*(k-1))*5000+1:(2*(k-1)+1)*5000);
  v2((k-1)*5000+1:k*5000)=v((2*(k-1)+1)*5000+1:k*10000);
end