how to calculate deviation for set of values??
3 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
M.Prasanna kumar
le 5 Fév 2020
Commenté : M.Prasanna kumar
le 16 Fév 2020
No of cases = 112; (112*9=1008)
in each case i have 9 obsevations( but there are missing values in between for which matlab treats them as Nan); so total i have an array of 1008*1
i calculted mean of 9 observations for each case. Now i want to calculate deviation of each observation( 9 observations) from the mean of that particular case.
M = strcat('iva','.xlsx' ); %% read excel file , iva file consists of 1008*1 array
M1 = xlsread(M);
mean_iva = zeros(112,1); %% initialising matrix
for ii = 1:9:1008
mean_iva(ii,1)= nanmean(M1(ii:ii+8)) %% calculating mean for each case
end
B = mean_iva(mean_iva~=0); %% MEAN for all 112 cases
dev = zeros(1008,1);
0 commentaires
Réponse acceptée
Guillaume
le 5 Fév 2020
You could do the same thing you've done for the mean, use a for loop.
However, a much simpler way is to reshape your input vector into 112 columns of 9 rows and simply call mean and std, no loop needed:
%M1: vector whose length is a multiple of 9
assert(mod(numel(M1), 9) == 0, 'Length of M1 must be a multiple of 9');
M1 = reshape(M1, 9, []); %reshape in rows of 9 elements
mean_iva = mean(M1, 1, 'omitnan'); %calculate the mean across the rows
std_iva = std(M1, 0, 1, 'omitnan'); %standard deviation (normalised by N-1) across the rows
3 commentaires
Guillaume
le 7 Fév 2020
You mean the want the difference from the mean? In this case, it's simply:
meandiff = M1 - mean_iva;
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Creating and Concatenating Matrices 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!