Question

I am converting a function in MatLab to C++ and come across this (in matlab):

  f = blocks(min:max,1:len);

with values: min = 153, max = 205

It is a 2D vector. So does the line of code above create a new 2D vector and copy the all of the blocks inside “blocks” to the new vector?

So in essence, it’s essentially a loop that starts at 153 ending at 250 and copies each of the blocks to the new vector?

Hope someone can help!

Answer 1

That statement takes rows between min and max and columns between 1 and len from blocks matrix and assigns them to f.

Let’s give this a try:

M = magic(5) % gives

M =

    17    24     1     8    15
    23     5     7    14    16
     4     6    13    20    22
    10    12    19    21     3
    11    18    25     2     9

M2 = M(2:4,1:3) % rows 2 to 4, columns 1 to 3

M2 =

    23     5     7
     4     6    13
    10    12    19

I don’t know C++ well but probably you will need 2 for loops to do that.