I forgot to say: StringSplit to split string. Good luck!

Depending if that is a string or an array of a strings or ....

Try looking up the functions Partition (to split it up in chunks). DateList/DateObject to convert a string to a date...

Hi Sander,

you are right. Same LeafCount, but 30% faster. I was also thinking in the wrong directions such as about extensions of the form 2(T-Y)/(T+Y).

Completely overlooked Ratios.

Cheers,

Marco

Hi Marco, All your time and help on this is very much appreciated. Thank you!

Differences[#]/Drop[#, -1] &@ts seems to sort it out,

Again thanks. Cheers,K.

Hi there,

suppose that you have the time series:

ts = RandomReal[1, {20}]
(*{0.818908, 0.355672, 0.696431, 0.391657, 0.0635299, 0.724865, \
0.555864, 0.185575, 0.589479, 0.478966, 0.379647, 0.0756852, 0.3155, \
0.89368, 0.725909, 0.134319, 0.211325, 0.699537, 0.740061, 0.879502}*)

Then this applies your function to ts:

Differences[#]/Drop[#, 1] &@ts
(*{-1.30242, 0.489293, -0.778163, -5.16493, 0.912356, -0.304033, \
-1.99536, 0.685188, -0.230731, -0.261609, -4.01614, 0.76011, \
0.646966, -0.23112, -4.40438, 0.364397, 0.697908, 0.0547568, 0.158546}*)

Check for the first value (second "day" actually)

(0.355672 - .818908)/0.355672= -1.30242

Also, a broader question would be, is there a way to visualize the code behind the functions in Mathematica? Or from Alpha? Functions like these have no documentation...

I do not understand what you mean.

Cheers,

Marco