help for diff log

[ecofin]

hi
in practice when i calculate the difference of the logarithm i use dlog(x) or i generate series, first i calculate the logarithm (genr y1=log(x)) second i use the difference ( genr y2=d(y1)), but if i would like to calculate the logarithm for all the series when i have just two observation in the first column and all the difference for the second column. see the picture below.
i don't know what i do :(
would you like to help me
best regrads

[EViews Gareth]

Code: Select all

smpl @first+2 @last log_x = log_x(-1)+r

[ecofin]

thanks for your help Mr Gareth :D