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## Re: Problem plotting time on X axis

 From: Ian McCallion Subject: Re: Problem plotting time on X axis Date: Thu, 15 Feb 2018 13:46:09 +0000

Hi Fritz,

I think this is what you want:

dtmeT = {"9:00:38" "9:00:39" "9:00:40" "9:00:41"}
T = [   23.900    23.900   22.900   21.100]

timeFormat='HH:MM:SS';
ser_date=(rem(datenum(dtmeT,timeFormat),1));
plot(ser_date,T ,'color','k'  );
datetick('x',13,'keepticks');
axis([-Inf Inf 20 75]);

Cheers... Ian

On 14 Feb 2018 9:37 pm, "Fritz Sonnichsen" <address@hidden> wrote:
Thanks Ian.
The seem to be in proper sequence. I am not asking you to do my work but to see this it may be easiest to just run this code below:

1;
clear all
fflush(stdin);
filenameT='C:\Users\fsonnichsen\Dropbox\CHANOS\LEDs\data\2018_02_14a\T.txt';
[dtmeT, T] = textread (filenameT, "%s %f");

%%%%%%%%%%  TEMPERATURE PLOT %%%%%%%%%%%%%%%
timeFormat='HH:MM:SS';
ser_date=datenum(dtmeT,timeFormat); %serial date is secs since 1/1/0000
plot(ser_date,T ,'color','k'  );
%  plot(ser_date-datenum("00:00:00"),T ,'color','k' )
datetick('x',timeFormat,'keepticks')
xlen = length(dtmeT);
axis([0 xlen 20 75])

return
==============DATA ="">==
14:30:06    22.8
14:30:07    22.8
14:30:08    22.8
14:30:09    22.8
14:30:10    22.8
14:30:11    22.7
===============================================
On 2/14/2018 4:03 PM, Ian McCallion wrote:
Are you sure all the dates are valid and in a sensible range?

On 14 Feb 2018 7:01 pm, "Fritz Sonnichsen" <address@hidden> wrote:
Octave 4.0.0
I am trying to plot a time series data. I found some examples and tried them but they don't seem to work. I have data as shown:
9:00:38      23.9
9:00:39      23.9
.....

My code looks like this:
timeFormat='HH:MM:SS';
ser_date=datenum(dtmeT,timeFormat); %serial date is secs since 1/1/0000
plot(ser_date,T ,'color','k'  );
datetick('x',timeFormat,'keepticks')
xlen = length(dtmeT)  ;
axis([0 xlen 20 35])

I get a time labeled axis as expected, but I do not see the plot of T.  The data is valid-if I plot it without time formatting it works fine.

thanks
fritz

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