xlim not working with datenum??

Hi there, I'm trying to set the limits of an x-axis of dates produced in a function. I have two inputs to the function, 'startdate' and 'enddate' which are entered in yyyymmdd format. i have tried the following code to limit the x-axis:

starty = floor(startdate/10000);
startm = floor(rem(startdate,10000)/100);
startd = rem(startdate,100);
xmin=datenum(datetime(starty,startm,startd));
endy = floor(enddate/10000);
endm = floor(rem(enddate,10000)/100);
endd = rem(enddate,100);
xmax=datenum(datetime(endy,endm,endd));
xlim([xmin xmax]);

but i just can't figure out why it doesn't work?? i get no error messages it just doesn't work? i have queried the x limits of the graph produced and get the following:

>> xlim

 ans =

 1.0e+05 *

 7.2592    7.3542

thanks for any help in advance

Answer 1

[Titus Edelhofer]

Hi Aaron,

here is an example how it works:

% three years:
t = datenum(2012, 1:36, 1)';
plot(t, rand(size(t)))
% makes it easier to read:
datetick x
% let's wait
pause(5);
% and "zoom" in:
xlim([datenum(2013, 1,1), datenum(2014,1,1)])

Titus

Answer 2

[Titus Edelhofer]

Hi,

I'm not yet sure what is the problem. You limit the X-axis to the following date range:

>> datestr(1e5 * [7.2592    7.3542])
ans =
02-Jul-1987
05-Jul-2013

So what is it that is not working?

Titus

[aaron Harvey]

Hi, its just plotting my full time series. the xlim in the function doesn't seem to limit the axis at all. If i run the function and then use xlim form the command window using the xmin and xmax datenums from above, it does limit the x-axis however it no longer plots any data, it just leaves a blank graph.

[aaron Harvey]

correction, it does limit it if i do it manually just took a while on my slow pc. however my function runs the line of code, but it does nothing.

xlim([xmin xmax]);

when copy the values of xmin and xmax that i created straight from the function and xlim([xmin xmax]) manually entering the datenumbers in the command line it works fine???

[Walter Roberson]

It is not clear at which point you do the xlim. You need to use it after you plot, or you need to set hold on after you xlim if you want to plot after you set xlim