i have a column array and i want to subtract each row by the first row and save.please help me in doing this

i have a column array and i want to subtract each row by the first row and save.please help me in doing this

Answer 1

[Star Strider]

Try this:

Array = randi(9, 5, 4);                                 % Create Data
Out = Array - Array(1,:);                               % Subtract First Row From All Rows

[Kurni Eswar]

Thanks alot It works :)

[Star Strider]

As always, my pleasure.

[Kurni Eswar]

I have one more problem. Please help me I want to remove 2 rows above and below, when the difference between two rows in first column is more than 2. For example: if have an array a=[0 2 2; 2 5 3; 4 2 6; 10 6 7; 12 5 9; 14 2 7; 15 5 6] i want a new array of

a= [0 2 2; 15 5 6]

[Star Strider]

This is obviously homework, so I am reluctant to give a complete solution. I will describe the approach instead.

You can find the indices of the rows matching those criteria with:

idx = find(diff([0; a(:,1)])>2);

(note that it is necessary to add a 0 at the beginning of the vector so the indices are correct), then choose all the rows defined by idx ±2 and delete them by setting them equal to the empty array, [].

That worked when I coded it.