MATLAB: Linearly “interpolate” a 1-dimensional vector

Question

Hello,

I have a vector of annual population figures for a number of years. I'd like to assume a linear growth and obtain the implied weekly figures. Is there an easier way than using interp1 and having to create an x grid of the years [1 2 3…] and the query points [1/52 2/52….1, 1 1/52, 1 2/52….]? Something like

[pop,txt,raw]= xlsread('annual population.xlsx');
pop=pop(:,1:2);
weekpop=[];
for i=1:21 %1997-2017 21 years 
    weekpop=[weekpop; linspace(pop(23-i,2),pop(23-1-i,2),52)'];
end

sort of works but doing linspace on a vector of values duplicates the end points (the pop in the 52nd week of year t-1 is the same as pop in week 1 of year t)

Thank you!

Answer 1

What's wrong with interp1?

pops    = flipud(pop(:,2));
n       = numel(pops);
weekpop = interp1(1:n, pops, linspace(1, n, (n-1) * 52))