The Trendy application is being retired in the new year. The new web application, ThingSpeak, offers similar functionality. We recommend that active Trendy users who are looking to create new trends use ThingSpeak. To begin collecting your data in ThingSpeak, please read the tutorial : ThingSpeak for Trendy users. Although Trendy no longer allows the creation of new trends, the application will still remain accessible until January 13, 2016. Until that date, you can view your current trends and download your data. After that date, your data will no longer be accessible. Thanks for using Trendy and we encourage you to check out ThingSpeak.


Solar Activity

This plot is broken.

Undefined function 'smooth' for input arguments of type 'double'.

Did you mean: correlation = smooth3(R,span); ?

This plot shows two indices of solar activity:

  • the Boulder Index of the observed sunspot number
  • the solar radio flux measured at a wavelength of 10.7 cm

The data is taken from the website once per day.

It also shows the correlation that has been observed between radio flux and sunspot number using the equations from the Bureau of Meteorology in Australia. These equations are only valid on a statistical (ie, average) basis, so the correlation is plotted as a smoothed 30 day moving average. The smoothed Sunspot Number (also a 30 day moving average) is plotted for comparison.

Plot Image
% Sunspot number
%   time vector is: time2088
%   data vector is: data2088

hold all

% Solar radio flux
%   time vector is: time2089
%   data vector is: data2089

hold all

% Calculate correlation between flux and sunspot number
F = (data2089 - 67.0);
R = (1.61*F) - (0.0733*F).^2 + (0.0240*F).^3;
correlation = R;
% smoothsunspot = smooth(data2088,span);
% hold all
% plot(time2088,smoothsunspot,'--','Color','red');

hleg1 = legend('Sunspot Number','Solar Flux at 10.7 cm','Correlation');

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