Need help in plotting with datenum on x-axis

Dear All

I am having problem in plotting i have a series of time data using:

out = datestr(ymdhms,'yyyy-mm-dd HH:MM:SS');

ymdhms was extracted from a text file.

I want to plot it against another: longi =

          256.242843281354
          296.110093347349
          296.882496353185
           296.94437904219
          138.658299669575
          339.725337924464
          339.894431814869
          338.304313807115
            222.2399243596
            222.3367026132
          222.460979592124
          222.463301950309

>>   whos longi
    Name        Size            Bytes  Class     Attributes

      longi      975x1              7800  double              

whos out
  Name        Size            Bytes  Class    Attributes

    out       975x19            37050  char

I get the error when plotting:

>> plot(out,longi)
Error using plot
Invalid first data argument

How can I plot with time of my interest? Below is my code for further understanding:

 =====================================================================
24652 1996-063A   ARABSAT-2B                                       
Launched: 1996-11-13 (318)           Start Date: 1996-06-12 (164)  
 Decayed:                             Stop Date: 2003-12-20 (354)  
=====================================================================
1 24652U 96063A   96318.74847837 -.00000020  00000-0  00000+0 0    14
2 24652   3.9929 210.6007 7281127 177.7757 190.4436  2.27277888    06
1 24652U 96063A   96319.62211352 -.00000020  00000-0  00000+0 0    31
2 24652   3.9929 210.3183 7284735 178.4392 185.2995  2.27373269    12
1 24652U 96063A   96319.62351606  .00008082  00000-0  30835-2 0    24
2 24652   3.9764 210.1654 7280836 178.5436 186.6267  2.27380102    20
1 24652U 96063A   96319.62356237  .00009638  00000-0  38025-2 0    37
2 24652   3.9632 210.3512 7280110 178.4006 186.6625  2.27374993    25
1 24652U 96063A   96320.05952563 -.00002597  00000-0 -98092-3 0    63
2 24652   3.9623 210.1661 7275699 178.7092 185.6294  2.27896863    39

<end of file>

        fid=fopen('2B.txt');
        A=textscan(fid,'%s','HeaderLines',5);
        Data=reshape(A{1}(1:end-3,:),9,[])';
        fclose(fid);

        l1=Data(1:2:end,:);
        l2=Data(2:2:end,:);

        epoch=l1(:,4);                  %complete epoch data

        a = str2double(epoch);
        y = fix(a/1000);
        ymdhms = datevec(datenum(y,0,a - y*1000)); % corrected
        [yearnow,~] = datevec(now);
        ymdhms(:,1) = (ymdhms(:,1) <= rem(yearnow,2000))*100 + 1900 + ymdhms(:,1);
        out = datestr(ymdhms,'yyyy-mm-dd HH:MM:SS');

        i= l2(:,3);          % inclination
        OM=l2(:,4);          % RAAN
        ecc=l2(:,5);          %Eccentricity
        w=l2(:,6);               %Argument of perigee
        M=l2(:,7);              %mean anomaly

        % Finding Longitude
        YYY=367*(year);
        MMM=fix((7/4)*((year)+fix((month+9)/12)));
        MMM2=fix(275*(month/9));
        DDD=day-730531.5;

        SMH=(((((sec)/60)+min)/60)+hour)/24;

        TT=YYY-MMM+MMM2+DDD+SMH;

        GST0=280.46061837 + (360.98564736629 *TT);
        mmod=mod(GST0,360);

        Ln=cellfun(@str2double,OM)+cellfun(@str2double,M)+cellfun(@str2double,w)- mmod;

        longi=mod(Ln,360);

Answer 1

[Thomas]

You cannot plot a datestr (i.e. out which is a str) against an integer (long: please try to use a variable name other than long )

plot(ymdhms,long)
datetick('x',yyyy-mm-dd HH:MM:SS')

if it is in datenum format

otherwise

 out=datenum(ymdhms,'yyyy-mm-dd HH:MM:SS');
 plot(out,long)
 datetick('x',yyyy-mm-dd HH:MM:SS')

[Hamza]

Dear Tom

Thanks again!

actually ymdhms is a 6 column integer. so when i plot it the result is 6 lines. I have updated my question and given the code. I just want to plot 'out' against 'longi'