What does this error mean?

2 次查看（过去 30 天）

Evan Mossel 2018-7-23

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/411771-what-does-this-error-mean

编辑： Evan Mossel 2018-7-26

I keep getting the error: Subscript indices must either be real positive integers or logicals.

days=10;
dy=-1;
hPlot1 = plot(dy,alt);
while dy<=days
%--calculate & display current time (UTC)
    yr=2018;
    mnth=1;
    dy=dy+1;
    hr=0;
    min=0;
    sc=0;
    d=datetime(yr,mnth,dy,hr,min,sc);
    %d=datetime('now');
%--covert and display current time in julian days
    JD_TT=juliandate(d);
%--convert julian days to moon position
    CooType='q2000';
    [X,Y,Z]=moonpos(JD_TT,CooType);
    %plot3(X,Y,Z);
%--convert to LLA coordinates, in degrees
    alt=sqrt(X.^2+Y.^2+Z.^2);
      xdata = get(hPlot1,'XData');
      ydata = get(hPlot1,'YData');
      set(hPlot1,'XData',[xdata dy],'YData',[ydata alt]);
end
altmax=max(ydata);
xmax=find(alt==altmax);
altmin=min(ydata);
xmin=find(alt==altmin);

15 个评论
显示 13更早的评论隐藏 13更早的评论

Walter Roberson 2018-7-24

Your xdata and ydata is going to include that initial nan value.

At the end of your loop, your xdata and ydata are not going to include the last dy and alt, because you change hPolt1's XData and YData after you assign to the temporary variable xdata and ydata.

Evan Mossel 2018-7-26