Given a vector of assorted positive integers, how to create a vector with the means of every 2 integers inserted between each other?

I've managed to take the mean of the whole vector with the mean function, but this doesn't seem like the right path to take. I am thinking of: v= 2 6 8 3 1 9 4 5 7 m1= v(1,2:9) m2= [m1,v(end)] m3= [v;m2] vmeans=mean(m2)

there are quite a few intermediate steps just to get to the vector of the means by themselves.

any answers to get to these values better or how to insert those values in between each original integer are much appreciated

thanx

Answer 1

[David Young]

result = interp1(v, linspace(1, length(v), length(v)*2-1), 'linear')

[Adam Quintero]

this looks like an elegant solution, and i want to make sure i understand the process. I see the seed vector (v) and the part that defines "the first and second number along (v)" in "...length(v),length(v)*2-1),.....". after i plug in some numbers im getting the math to work out. i am starting to see how i need to break these problems down, thank you for the elegant solution, this points me in the right direction.

[David Young]

Yes, to understand this it may help to note that, for example

linspace(1, 3, 5)

gives

[1 1.5 2 2.5 3]

- that is, the points in the index space of v for which you want to find values.

Answer 2

[David Young]

result(1:2:2*length(v)-1) = v;
result(2:2:2*(length(v)-1)) = conv(v, [1 1]/2, 'valid')

Answer 3

[Andrei Bobrov]

m2 = v([2:end,end]);
m3 = [v;m2];
vmeans = mean(m2);

EDIT

vout = reshape([v;conv(v,[1 1],'valid')/2 0],1,[]);
vout = vout(1:end-1);

more only it case

vout = interp1(1:length(v),v,1:.5:length(v));

[Adam Quintero]

This helps get to a 2x9 set with which to calculate the mean values for insertion, but does not address how to get those values in the original vector and be in the order v1,vmeanof1-2,v2,vmeanof2-3, ..... i have been working on this and have no solution yet

[Andrei Bobrov]

what is it vmeanof1-2? it mean(v(1:2)) or ..?

[Adam Quintero]

vmean1-2 is the mean betweeen the first and second number in the original vector. i am trying to set this up so that the mean is in between the values used to calculate it. i want to add a row vector value in between the values of a row vector. the numbers to add are the means of the two numbers before and after it

[David Young]

It's more efficient to divide the mask in the convolution by 2, rather than dividing the result of the convolution by 2.

linspace is preferable to using the colon operator if the output needs to be a definite length and the increment is not an integer.

Answer 4

[David Young]

v= [2 6 8 3 1 9 4 5 7];  % data
m = (v(1:end-1)+v(2:end))/2;
t = [v; [m 0]];
t = t(:);
result = t(1:end-1).'