"Index exceeds the number of array elements (217)"

Why does MATLAB show me the following error?

"Index exceeds the number of array elements (217)"

I am trying to find the mean for different rows in 1 column and I have 217 rows. I used the following code:

mean(RT([8 12 25 28 30 39 40 48 52 56 58 59 60 63 70 72 97 100 101 102 105 122 123 478 131 132 143 150 164 181 186 191 198 199 211:217,1]))

Why isn't it letting me carry out this function?

Answer 1

[Jeremy]

If you have 217 rows and you're trying to index row 478 then Matlab will throw an error

also, the ,1 will need to be outside the row bracket.

mean(RT([8 12 25 28 30 39 40 48 52 56 58 59 60 63 70 72 97 100 101 102 105 122 123 478 131 132 143 150 164 181 186 191 198 199 211:217],1))

[Khayroon Suleyman]

THANKYOU IT WORKED PERFECTLY!