Warning: Integer operands are required for colon operator when used as index

Hi, so I think i know what the issue is, that being the " /2 " portion of the code giving a decimal as an answer, but I thought the addition of " .5 " would fix that as it gives me all my correct values. My question is, does this warning actually affect the out come of my calculations?

    pixel_seg.A81 = middle.middle_interpolate((28536/2+.5):(28598/2),:);  %gives warning
    pixel_seg.B81 = middle.middle_interpolate((28599/2+.5):(28634/2),:);  %gives warning

    tap.tapA81B81 = (((abs((sum(pixel_seg.A81)/length(pixel_seg.A81))-...
        (sum(pixel_seg.B81)/length(pixel_seg.B81))))/...
        (sum(pixel_seg.B81)/length(pixel_seg.B81)))*100);

Thanks for your time

Answer 1

[Walter Roberson]

28536 is already even, so do not add 0.5 after dividing by 2.

28599 is odd, so it would need to be rounded after dividing by 2.

Using floor() or ceil() is safer than adding 0.5, due to potential round-off error.

[Benjamin]

Ahh good eye Walter, It should have been 63 and not 36. So when doing for example: 28563/2, instead of adding .5, which of the two functions that you listed would round up ( as in every case the number is rounded up)

[Andrei Bobrov]

please use 'ceil'

[Benjamin]

Thanks so much guys