How can I use interp1 to interpolate the last row of a matrix?

I have the following 4 x 3 matrix:

A = [1,2,3;4,5,6;7,8,9;10,11,12]

I want to interpolate the rows of this matrix and get a 5 x 3 matrix to just get a single, last interpolated row. I am not sure how to use interp1 to this end. Can someone please help? Thank you!

Answer 1

[Voss]

Here's my guess at what you mean:

A = [1,2,3;4,5,6;7,8,9;10,11,12]

A = 4×3

1 2 3 4 5 6 7 8 9 10 11 12

N = size(A,1);
A(N+1,:) = interp1(1:N,A,N+1,'linear','extrap')

A = 5×3

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Answer 2

[Bora Eryilmaz]

Interpolation is probably not the right term here since interpolation, typically, requires a set of (x,y) data and a different set of x values to use for finding interpolated y values.

A simple approach could be to use the column means of the A matrix to find the row of average values:

A = [1,2,3;4,5,6;7,8,9;10,11,12]

A = 4×3

1 2 3 4 5 6 7 8 9 10 11 12

A(end+1,:) = mean(A)

A = 5×3

1.0000 2.0000 3.0000 4.0000 5.0000 6.0000 7.0000 8.0000 9.0000 10.0000 11.0000 12.0000 5.5000 6.5000 7.5000