Linearly "interpolate" a 1-dimensional vector

3 vues (au cours des 30 derniers jours)
wy6622
wy6622 le 13 Fév 2019
Commenté : Jan le 14 Fév 2019
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!

Réponse acceptée

Jan
Jan le 13 Fév 2019
What's wrong with interp1?
pops = flipud(pop(:,2));
n = numel(pops);
weekpop = interp1(1:n, pops, linspace(1, n, (n-1) * 52))
  2 commentaires
wy6622
wy6622 le 13 Fév 2019
I wasn't able to come up with an elegant way to write the query points like your "linspace(1, n, (n-1) * 52)". Thank you!
Jan
Jan le 14 Fév 2019
You are welcome.

Connectez-vous pour commenter.

Plus de réponses (0)

Catégories

En savoir plus sur Interpolation dans Help Center et File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by