Formatting Sea Level Data

Hello to everyone,

I am pretty new with Matlab and I dont know how to get this right. I am trying to process some data carrying sea level information. The file contains 17858 lines where each line corresponds to half day of sea level measurements; this is the first line of the pack:

200901011 2199 2096 1923 1777 1679 1650 1697 1796 1907 2007 2065 2073

where the first number of each line (ie 200901011) represents "year-month-day-halfday" and the rest of the numbers are sea level measurements in mm for every hour during the halfday itself. I am attaching one mat file to clarify.

I would like to process the data being able to plot time vs. sea level but I don't know how to extract the different variables and get the proper time series, particularly when it comes to join the data corresponding to the same day (halfday+halfday). Maybe it is simple and straightforward but this is when you know the bussines...

Thanks very much in advance!

Edu

Answer 1

[Mischa Kim]

Edu, this should do:

ndays = length(data(:,1))/2;
ndata = ndays*24;
Tdata = data(:,1);
Rdata = reshape(data(:,2:end)',ndata,[]);  % turn data into a singular column vector

tloc  = 12*find((Tdata - 1e3*round(Tdata/1e3)) == 11); % find 1st of month for tick labeling
tlab  = {'Jan','Feb','Mar','Apr','May','Jun',...      
         'Jul','Aug','Sep','Oct','Nov','Dec'};         % corresponding tick labels

tspan = 1:ndata;
plot(tspan,Rdata,'+-b')
xlabel('Month')
ylabel('[your ylabel]')
title('[your title]')
grid;
set(gca,'XTick',tloc,'XTickLabel',tlab)

[Edu PL]

Hi Mischa. Yes it is exactly the routine I was looking for. Thanks very much! (by the way what if I have more than 1 year of data? how can I make a difference in the x axis?)

Thanks for the time and effort put on this and sorry to get back to you a bit late.

Regards!!

Edu