Hi, this is the magnitude of your time-dependent temperature value which you created in a tabular (amplitude).

Hi, I would add to Bekhzad's answer that

Temperature(time) = Magnitude * Amplitude(time). Also, look at http://130.149.89.49:2080/v6.14/books/usi/default.htm?startat=pt03ch16s10hlb13.html

Thank you both sir

So, victor

temperature(time) means temperature in a specific time? amplitude (time) means?

Cause each time/frequency has its own specific amplitude and therefore, wih this formula magnitude is different for each tab!

Yes, temperature(time) means temperature in a specific time,

amplitude (time) means linearly interpolated value based on your tabular data (timei, amplitude(timei), i=1,2,...), i.e.

amplitude (time)=amplitude (timei)+(time-timei)/(timei+1-timei)*(amplitude (timei+1)-amplitude (timei)) for timei