Starting 'for' loop from integers (for e.g. 7 ) after 1 and not counting lower integers value (for e.g. 1-6)?

I am starting a for loop as,

for I=7:12

end

and expect the results which are meant to be from 7 to 12. But I am also getting values (however they are zero) for I=1:6 as

         0         0         0         0         0         0         0         0         0         0
         0         0         0         0         0         0         0         0         0         0
         0         0         0         0         0         0         0         0         0         0
         0         0         0         0         0         0         0         0         0         0
         0         0         0         0         0         0         0         0         0         0
         0         0         0         0         0         0         0         0         0         0
  316.2000  294.7000  279.1000  295.7000  298.5000  286.0000  252.6000  254.5000  276.2000  294.4000
  485.0000  466.1000  463.2000  460.2000  489.2000  476.7000  396.5000  420.7000  443.8000  465.3000
  509.9000  485.5000  486.3000  483.1000  483.6000  491.0000  414.2000  428.8000  470.8000  486.7000
  517.6000  505.3000  508.5000  511.1000  501.1000  506.5000  442.7000  461.1000  505.6000  507.5000
  473.8000  445.7000  455.7000  433.0000  455.6000  450.9000  367.2000  400.6000  422.5000  435.5000
  481.4000  457.0000  457.5000  445.6000  459.5000  452.6000  389.8000  402.8000  431.7000  445.7000

How do I avoid zeroes?

Answer 1

[Christopher Madec]

What do you want to have instead of zeros ? Matlab automatically assign a 0 for lower values if you not putting any value on them with your loop. You could potentially put Not an Number (NaN) values with:

for ii=1:6
  A(ii)=NaN;
end

[Raju]

Hello, Thank you for your answer. I do not want these zero values (i=1:6) in my result.

[Guillaume]

@Raju,

You've left out what goes inside your loop leaving it up to us to guess what your problem is. My guess, is that you've written something like:

for i = 7:12
  something(i, :) = somethingelse
end

In matlab matrix indices always start at 1. The first row of matrix is always index 1. It can't be an arbitrary number such as 7. Thus if you tell matlab to fill row 7 with something, it will also create row 1 to 6 and fill them 0.

Whether you want it or not, that's what matlab does. If you do not want these row of 0, then start filling from row 1, e.g.:

for i = 7:12
  rowindex = i-6;
  something(rowindex, :) = somethingelse;
end