Tukukkk

I'm trying to plot a function I fitted to a dataset, but the line plot does not connect the points on the function's graph correctly:(green points are original data, blue circles are points on the function and blue line should be connecting the blue circles.) The problem seems to have begun after I started converting milliseconds from epoch to date (x-axis).

%convert millis since epoch to days since 0000

  timeVec = zeros(size(x,1), 1);

  f = "ddd mmm dd HH:MM:SS yyyy";



  for i = 1:size(x,1)

    timeTmp = ctime(x(i)/1000);

    timeVec(i) = datenum(timeTmp(1:end-1), f);

  endfor

  %



  %convert millis since epoch to days since 0000 (now for the training set examples)

  timeVecXX = zeros(size(XX,1), 1);



  for i = 1:size(XX,1)

    timeTmp = ctime(XX(i)/1000);

    timeVecXX(i) = datenum(timeTmp(1:end-1), f);

  endfor

  %



  hold("off");

  plot(timeVec, plotFunc(x), '-ob');

  datetick("ddd mmm dd");

  hold("on");

  grid on;

  plot(timeVecXX,yy, '.g');

MCVE:

optimTheta = [8.0916e+004; -3.4102e+003; 7.5091e+003];

 optimA = 78250000;

 mu = [1.5431e+012, 5.8217e-003];

 s = [2.4831e+007, 7.1022e-001];



  plotFunc = @(p) predict(p,optimTheta,mu,s,optimA);



  linZero = -(optimTheta(1)*s(1)-optimTheta(2)*mu(1))/optimTheta(2)   %solution for the equation theta0 + theta1*(x-mu(1))/s(1) = 0



  x = [1543076107026:(linZero-1543076107026)/100:linZero];

  x = x';



  %convert millis since epoch to days since 0000

  timeVec = zeros(size(x,1), 1);

  f = "ddd mmm dd HH:MM:SS yyyy ";



  for i = 1:size(x,1)

    timeTmp = ctime(x(i)/1000);

    timeVec(i) = datenum(timeTmp, f);

  endfor

  %



  hold("on");

  plot(timeVec, plotFunc(x), 'o-b');

  datetick("ddd mmm dd");

  grid on;

  xlabel ("Day");

  hold("off");

function [y] = predict (X, theta, mu, s, a)



  Xtemp = [X, sin((X-a)/(1000*60*60*24/(2*pi)))];

  Xtemp = (Xtemp-mu)./s;

  Xtemp = [ones(size(Xtemp,1),1), Xtemp];



  y = Xtemp*theta;



endfunction

Got it working like this:

 optimTheta = [8.0916e+004; -3.4102e+003; 7.5091e+003];

 optimA = 78250000;

 mu = [1.5431e+012, 5.8217e-003];

 s = [2.4831e+007, 7.1022e-001];



 plotFunc = @(p) predict(p,optimTheta,mu,s,optimA);



 linZero = -(optimTheta(1)*s(1)-optimTheta(2)*mu(1))/optimTheta(2);  %solution for the equation theta0 + theta1*(x-mu(1))/s(1) = 0



 tOffset = 1543076107026;



 x = [1543076107026:(linZero-1543076107026)/100:linZero];

 x = x';



 timeVec = x-tOffset;



 xTicks = [-65707026:(24*60*60*1000):539092974];



 hold("on");

 set(gca, 'xtick', xTicks);

 plot(timeVec, plotFunc(x), '-ob');



 lTVec = ;

 for i=1:size(xTicks,2)

 lTVec = [lTVec; strftime("%a %b %d", localtime((xTicks(i)+tOffset)/1000))];

 endfor





 set(gca, 'xticklabel', lTVec);

 grid on;

 xlabel ("Day");

 hold("off");

graph