How to use time (in year) as your x axis for plots when your data is in quarters in Matlab?

Hello everyone,

I am working on time series data, and have been trying to change my x axis to show number of years or to show not all the quarters. My data is in quarters, starting from 1997, ending in 2010. However, when I try plotting my figures, all quarters are shown, and I have't been able to eliminate any quarters. Showing all quarters on the plot makes it really congested looking, despite using xtick_rotate.

Questions: 1. Is it possible to show say just Q1 1997, Q1 2002, Q1 2007, etc?

2. Is it possible to show say 1997, 1998, 1999, 2000? which means I want to show the year instead of quarters, for my quarterly data?

Many thanks!! :)

Answer 1

[Walter Roberson]

datetick('x', 'yyyy QQ')

[jj]

Thank you! That does work. However, I've just modified my question, as the initial plan to plot quarters makes the graph really congested.

[Walter Roberson]

You can use

datetick('x','yyyy')

to show just the year.

Beyond that, you should be investigating setting the XTick property of the axis.

[Walter Roberson]

years = 1997:2010

numyears = length(years);

jan1s = zeros(numyears,1);

quarters = zeros(4,numyears);

for Yearno = 1:numyears

thisyear = years(Yearno);

jan1s(Yearno) = datenum([thisyear 1 1]);

quarters(1,Yearno) = jan1s(Yearno);

quarters(2,Yearno) = datenum([thisyear 4 1]);

quarters(3,Yearno) = datenum([thisyear 7 1]);

quarters(4,Yearno) = datenum([thisyear 10 1]);

end

plot(quarters(:),F01);

set(gca,'XTick', jan1s);

datetick('x', 'yyyy');

Answer 2

[karan]

Since you havent given the exact possibility ..here is an example of how you would show am/pm in ur plot for every two hours

two_hour = 2/24;

set(gca,'XTick',[two_hour:two_hour:1]); set(gca,'XTickLabel',{'2AM','4AM','6AM','8AM','10AM','12PM','2PM','4PM','6PM','8PM','10PM','12AM'}); set(gca,'XMinorTick','On');

try your case similarly and it will work...the ideology is the same.. i hope this helps

[jj]

Thank you! That did manage to give me the years I wanted. But, they were all clustered together, and my plot wasn't showing up. What could have gone wrong? My code is as follows:

startDate = datenum('1997,01,01')

endDate = datenum('2010,12,31')

fourteen_year = 2/14;

plot(fourteen_year,F01);

title('Real activity factor')

set(gca,'XTick',[fourteen_year:fourteen_year:1]);

set(gca,'XTickLabel',{'1997','1999','2001','2003','2005','2007','2009'});

Also, do I have to repeat the same steps for the axis for each subplot I want to do? I tried having all the steps in front, before going ahead with my subplots. But, it didn't work.

Thank you!

[karan]

yes i think you need to do it separately for the subplots ...you can try to have lesser points in order to accommodate the text supporting the ticks...and have minor ticks showing yearly increment ....this will not congest your axis.

Another opinion is to forget about the whole year format ...try using Y97, Y99 or simply 97, 99, 01

If you like my answers and suggestions please accept this answer...cheers!!!

[Walter Roberson]

If all the subplots are based on the same time reference, then you can calculate the locations of all of the ticks ahead of time, and then you only need to

set(gca,'XTick', jan1s);

datetick('x', 'yyyy');

for each subplot