Run length encoding error

Hi,

I'm trying to do RLE encoding using data sheet with temeperature values, but it gives me an error : "Index in position 1 is invalid. Array indices must be positive integers or logical values" for line 15. Can't find the solution for this.

clear all
clc
data = importdata('Temperature.mat');
j = 1;
elems = zeros(length(data),1); % store repeated elements
for i = 1:length(data)
    if isempty(find(elems == data(i)))
        elems(j) = data(i);
        j = j + 1;
    end
end
elems
t = tabulate(data); % get frequency table
for n = 1:length(elems);
    lens(n) = t(elems(n),1); % get how many each element in elems vector occurs
end
lens

Answer 1

[Ameer Hamza]

I didn't understand the logic of your code, but here is an alternate solution.

clear all
clc
data = importdata('Temperature.mat');

grps = cumsum([0; diff(data)~=0])+1;
parts = splitapply(@(x) {x}, data, grps);
rle = cellfun(@(x) [x(1) numel(x)], parts, 'uni', 0);
rle = vertcat(rle{:});

First column is values and second column is counts.

[Dmitrij Linivenko]

Thanks. Now I just need to figure out what those unknown functions do as i've never seen them :D

[Ameer Hamza]

I am glad to be of help! You can run each line one by one to get some idea which each step is doing. Documentation will also be helpful.