How to fill zeros and NaNs with the average of the previous nonzero consecutive values

Hi fellow helpers!

So, i have a column like this:

T = [0;0;1;2;3;4;NaN;4;3;0;0;0;NaN;4;2;3;0;2;0];

And everytime I have a NaN or a zero, I would like to transform them in the average of the previous nonzero consecutive values (averages in bold):

T = [0;0;1;2;3;4;2.5;4;3;3.5;3.5;3.5;3.5;4;2;3;3;2;2];

I cannot figure out how I can do this in an efficient way (without for loops, because the column has thousands of rows).

I hope you can help me out! Thanks! :)

Answer 1

[Matt J]

Using this FEX download,

https://www.mathworks.com/matlabcentral/fileexchange/78008-tools-for-processing-consecutive-repetitions-in-vectors

T = [0;0;1;2;3;4;NaN;4;3;0;0;0;NaN;4;2;3;0;2;0];

idx=find(T,1);
[stem,T]=deal(T(1:idx-1),T(idx:end));

G=groupTrue(~isnan(T) & T~=0);
[~,~,lengths]=groupLims(groupTrue(~G),1);

T(~G)=repelem( groupFcn(@mean,T,G) ,lengths);

T=[stem;T]

T'

ans =

Columns 1 through 9

0 0 1.0000 2.0000 3.0000 4.0000 2.5000 4.0000 3.0000

Columns 10 through 18

3.5000 3.5000 3.5000 3.5000 4.0000 2.0000 3.0000 3.0000 2.0000

Column 19

2.0000

[Margarida]

Thank you!! I only changed the first line to idx=find(T,1,'first') to generalize it. :)

[Matt J]

That shouldn't have made any difference. The 'first' flag is set internally by default.

[Margarida]

lol, indeed...