changing mean and median

i have a column vector of 100 rows and would like to calculate its progressive median and mean for example (at the first row, only consider that row; at second row, consider first 2 rows; at third row, consider the first 3 rows and so on upto 100th row). I have used a for loop with sum/i to calculate the mean but I have failed to break through in calculating median. Kindly provide a solution or any alternatives.

[Fangjun Jiang]

Can't you use mean() and median()?

[Anita Nabatanzi]

when i use mean() and median() it calculates for all 100 samples at a go yet I need a value at each stage.

[Rachel Surridge]

Does your data have more than one column?

[Anita Nabatanzi]

working with one column for now, will expand it out to the rest of the matrix if successful at this stage.

Answer 1

[Fangjun Jiang]

M=100;
data=(1:M).';

MeanData=data;
MedianData=data;
for k=1:M
MeanData(k)=mean(data(1:k));
MedianData(k)=median(data(1:k));
end

[Anita Nabatanzi]

thank you Jiang, checked this for randomly generated data and it works, will apply it to my larger data, thanks.

[Rogers Tuyisenge]

i wish to solve a similar problem but for a 600x200 matrix (data) and my code is not far from what Fangjun Jiang has. I am using nested for loops so that the calculation is done for all 600 rows but my results are incorrect. any ideas? a part of my code looks like this;

m=600

n=200

for k=1:m

for h=1:n

Mean_answer(k,h)= mean(data(1:h))

end

end

[Bruno Luong]

You miss the row index in the data

Mean_answer(k,h)= mean(data(k,1:h))    

[Rogers Tuyisenge]

Thanks mate, this fixes the problem!