Thread Subject:

Plot date labels

Hi everybody, I have a 2 column matrix to plot, one with the dates in number and the other column with the values. My problem is the date labels to plot on the x axis, because if I have 100obs I cannot print 100 date labels. In order to face it I tried with some loops but I have an inconsistency on the time range (same space interval different time period of months). I suppose there is an easy way to do it, so if I have a column-vector x with the dates in number and y with the values. What I have to do in order to plot it?

"mklcst mklcst" wrote in message <k00t34$t35$1@newscl01ah.mathworks.com>...
> Hi everybody, I have a 2 column matrix to plot, one with the dates in number and the other column with the values. My problem is the date labels to plot on the x axis, because if I have 100obs I cannot print 100 date labels. In order to face it I tried with some loops but I have an inconsistency on the time range (same space interval different time period of months). I suppose there is an easy way to do it, so if I have a column-vector x with the dates in number and y with the values. What I have to do in order to plot it?

Providing your number-dates are Matlab datenums, just plot(x,y) as normal and then do:
datetick x % or datetick('x')

Alternatively, open the documentation with "doc" and search for something like "plot dates".

Thank you Justin.
But I don't see the label in date format as 'mmm-yy' but in numeric one.
If I set "set(gca,'XTick',x)" I see an overlapped text and plot.


"Justin Ashmall" <juestan-matlabnews6h8@yahoo.co.uk> wrote in message <k00u6p$3hq$1@newscl01ah.mathworks.com>...
> "mklcst mklcst" wrote in message <k00t34$t35$1@newscl01ah.mathworks.com>...
> > Hi everybody, I have a 2 column matrix to plot, one with the dates in number and the other column with the values. My problem is the date labels to plot on the x axis, because if I have 100obs I cannot print 100 date labels. In order to face it I tried with some loops but I have an inconsistency on the time range (same space interval different time period of months). I suppose there is an easy way to do it, so if I have a column-vector x with the dates in number and y with the values. What I have to do in order to plot it?
>
> Providing your number-dates are Matlab datenums, just plot(x,y) as normal and then do:
> datetick x % or datetick('x')
>
> Alternatively, open the documentation with "doc" and search for something like "plot dates".

"mklcst mklcst" wrote in message <k02bte$l1q$1@newscl01ah.mathworks.com>...
> Thank you Justin.
> But I don't see the label in date format as 'mmm-yy' but in numeric one.
> If I set "set(gca,'XTick',x)" I see an overlapped text and plot.

Are your dates Matlab datenums?
> > Providing your number-dates are Matlab datenums

Did you check the documentation?
> > open the documentation with "doc" and search for something like "plot dates".

Looking at the the documentation for datetick it says:
"The axis data values should be generated by or be compatible with the output of the datenum function."

I suspect your "dates in number" are some odd format and that's why it's not working. You don't give any examples so it's impossible to tell.

My dates vector in in datenum, the problem is that if I set the gca Thr plot is overlapped... I searched on DOC and also I googled it my I didn't find a solution to my problem.
So let's start with an example, suppose you have 1200 of monthly obs (for conveniente se simulate from a standard normal) and a vector of datenums from 1/1/1900 to 31/12/1999.
Can you show me how to proceed?


"Justin Ashmall" <juestan-matlabnews6h8@yahoo.co.uk> wrote in message <k02ot9$riq$1@newscl01ah.mathworks.com>...
> "mklcst mklcst" wrote in message <k02bte$l1q$1@newscl01ah.mathworks.com>...
> > Thank you Justin.
> > But I don't see the label in date format as 'mmm-yy' but in numeric one.
> > If I set "set(gca,'XTick',x)" I see an overlapped text and plot.
>
> Are your dates Matlab datenums?
> > > Providing your number-dates are Matlab datenums
>
> Did you check the documentation?
> > > open the documentation with "doc" and search for something like "plot dates".
>
> Looking at the the documentation for datetick it says:
> "The axis data values should be generated by or be compatible with the output of the datenum function."
>
> I suspect your "dates in number" are some odd format and that's why it's not working. You don't give any examples so it's impossible to tell.

On 8/10/2012 9:26 AM, mklcst mklcst wrote:

[Do NOT toppost...hard conversation follow makes]

> My dates vector in in datenum, the problem is that if I set the gca Thr
> plot is overlapped......

You don't set gca, you use datetick()

doc datetick % and friends...

--

Yes I use: datetick(xData,'mmm-yy','keeplimit');
where xData is a datenum vector.
The problem is that I see in the plot the x-axis label in number

dpb <none@non.net> wrote in message <k036js$e2g$1@speranza.aioe.org>...
> On 8/10/2012 9:26 AM, mklcst mklcst wrote:
>
> [Do NOT toppost...hard conversation follow makes]
>
> > My dates vector in in datenum, the problem is that if I set the gca Thr
> > plot is overlapped......
>
> You don't set gca, you use datetick()
>
> doc datetick % and friends...
>
> --

On 8/10/2012 9:26 AM, mklcst mklcst wrote:
...

> So let's start with an example, suppose you have 1200 of monthly obs
> ... and a vector of datenums from 1/1/1900 to 31/12/1999.
> Can you show me how to proceed?
...

 >> t=linspace(datenum(1900,1,1),datenum(1999,12,31),1200)';
 >> d=rand(size(t));
 >> plot(t,d)
 >> datetick('x','yyyy')

--

On 8/10/2012 10:11 AM, mklcst mklcst wrote:

{TOP POSTING REPAIRED (ONCE) NO MORE RESPONSES IF YOU PERSIST)

> dpb <none@non.net> wrote in message <k036js$e2g$1@speranza.aioe.org>...
>> On 8/10/2012 9:26 AM, mklcst mklcst wrote:
...

>> You don't set gca, you use datetick()
...
 > Yes I use: datetick(xData,'mmm-yy','keeplimit');
 > where xData is a datenum vector.
...

doc datetick

NB the first argument definition per documentation.

> datetick(tickaxis) labels the tick lines of an axis using dates,
> replacing the default numeric labels. tickaxis is the string 'x',
> 'y', or 'z'. The default is 'x'.

--

ok, I get it. What about if I want to increase the number of displayed labels?

dpb <none@non.net> wrote in message <k03adt$o0s$1@speranza.aioe.org>...
> On 8/10/2012 10:11 AM, mklcst mklcst wrote:
>
> >> On 8/10/2012 9:26 AM, mklcst mklcst wrote:
> ...
>
>

On 8/10/2012 12:15 PM, mklcst mklcst wrote:
> ok, I get it. What about if I want to increase the number of displayed
> labels?

doc datetick

--

I don't understand if I have to build manually the vector of dates.

dpb <none@non.net> wrote in message <k03h04$914$1@speranza.aioe.org>...
> On 8/10/2012 12:15 PM, mklcst mklcst wrote:
> > ok, I get it. What about if I want to increase the number of displayed
> > labels?
>
> doc datetick
>
> --

"mklcst mklcst" wrote in message <k050as$enf$1@newscl01ah.mathworks.com>...
> I don't understand if I have to build manually the vector of dates.

t=now+(1:10);
plot(t,rand(size(t)));

set(gca,'xtick',t,'xlim',t([1 end]));
datetick('x','keeplimits','keepticks');

% Bruno

Bruno maybe you enlightened me, so if xData is my "t" (as in your example) if I code:
set(gca,'xtick',xData([1,50,100,150,300,end]),'xlim',xData([1 end]));

I enable the label of obs 1, 50, 100, 150,300, end ?




"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <k054nf$qmn$1@newscl01ah.mathworks.com>...
> "mklcst mklcst" wrote in message <k050as$enf$1@newscl01ah.mathworks.com>...
> > I don't understand if I have to build manually the vector of dates.
>
> t=now+(1:10);
> plot(t,rand(size(t)));
>
> set(gca,'xtick',t,'xlim',t([1 end]));
> datetick('x','keeplimits','keepticks');
>
> % Bruno

"mklcst mklcst" wrote in message <k035m2$bo4$1@newscl01ah.mathworks.com>...
> My dates vector in in datenum, the problem is that if I set the gca Thr plot is overlapped... I searched on DOC and also I googled it my I didn't find a solution to my problem.
> So let's start with an example, suppose you have 1200 of monthly obs (for conveniente se simulate from a standard normal) and a vector of datenums from 1/1/1900 to 31/12/1999.
> Can you show me how to proceed?
>
>
> "Justin Ashmall" <juestan-matlabnews6h8@yahoo.co.uk> wrote in message <k02ot9$riq$1@newscl01ah.mathworks.com>...
> > "mklcst mklcst" wrote in message <k02bte$l1q$1@newscl01ah.mathworks.com>...
> > > Thank you Justin.
> > > But I don't see the label in date format as 'mmm-yy' but in numeric one.
> > > If I set "set(gca,'XTick',x)" I see an overlapped text and plot.
> >
> > Are your dates Matlab datenums?
> > > > Providing your number-dates are Matlab datenums
> >
> > Did you check the documentation?
> > > > open the documentation with "doc" and search for something like "plot dates".
> >
> > Looking at the the documentation for datetick it says:
> > "The axis data values should be generated by or be compatible with the output of the datenum function."
> >
> > I suspect your "dates in number" are some odd format and that's why it's not working. You don't give any examples so it's impossible to tell.

Hello Justin Ashmall,
I am experiencing the same problem described below. How could I get this fixed?
Cheers,
Juliana
 

On 5/4/2013 9:13 AM, Juliana Santos wrote:
...

> I am experiencing the same problem described below. How could I get this
> fixed?
...

Well, there is no "below" but as the responses in the thread in general
note, to display dates on an axis w/ Matlab,

a) generate the subject axis values via datenum() and friends, and

b) utilized datetick() on the proper axis w/ format and all as desired

doc datenum % and friends
doc datetick

No specifics shown, no specifics in response are possible...

--