Re: Plot

[Thomas D. Dean]

I will try again.

I exercise for twenty minutes, two times per day, with the heart rate 
monitor generating a reading every second.  If I start at 10AM, I have 
1200 samples with time stamps of 10:00:00. 10:00:01, etc.  If I start 
again at 2PM, I have 1200 samples with time stamps of 14:00:00, 
14:00:01, etc.  So, my data file has two columns, a time stamp and a 
heart rate.  But the data is not evenly spaced in time.

I am reading this data from a file that changes in size, growing some
2600 lines per day.  The file currently has 84000+ entries of a time
stamp and a heart beat rate, I called bmp from the mfg's android app.

Here is a function that generates data that has similar clumping.  This 
is not part of my problem, just a function that will generate data with 
similar grouping.

function [] = make_file()
  T=[]; B=[];
  for day=1:29
    t1=day+(10+([1:1400]/60/60))/24;
    t2=day+(16+([1:1520]/60/60))/24;
    bmp1=(1+rand(size(t1)))*10+80;
    bmp2=(1+rand(size(t2)))*10+83;
    T=[T;t1';t2'];
    B=[B;bmp1';bmp2'];
  endfor;
  fd = fopen("xx.dat","w");
  fprintf(fd, "%f %d\n",[T,B]');
  fclose(fd);
endfunction;

make_file();

[A,B] = textread ("xx.dat", "%f %d");
## if I plot time vs bmp, I get one group of bmp values in one vertical
## line with a line connecting to the next group of bmp values.
plot(T,B);
## plot with points demonstrates this:
plot(T,B,'.');
## I want the plot to look something like this:
plot(B);

Tom Dean