Hello, I have a table grouped by instrument:
instrument TR
-----------------
AU200_AUD 66.1
AU200_AUD 114.1
AU200_AUD 72.9
AU200_AUD 121.3
AU200_AUD 83.15
AUD_CAD 0.00975
AUD_CAD 0.01005
AUD_CAD 0.00435
AUD_CAD 0.00755
AUD_CAD 0.00748
AUD_CHF 0.026975
AUD_CHF 0.011215
AUD_CHF 0.007245
AUD_CHF 0.01373
AUD_CHF 0.010555
AUD_JPY 0.8835
AUD_JPY 1.1165
AUD_JPY 1.0055
AUD_JPY 1.3975
AUD_JPY 1.6915
I want to update TR so TR:TR*-1 in every row after the third one per instrument:
instrument TR
-----------------
AU200_AUD 66.1
AU200_AUD 114.1
AU200_AUD 72.9
AU200_AUD -121.3
AU200_AUD -83.15
AUD_CAD 0.00975
AUD_CAD 0.01005
AUD_CAD 0.00435
AUD_CAD -0.00755
AUD_CAD -0.00748
AUD_CHF 0.026975
AUD_CHF 0.011215
AUD_CHF 0.007245
AUD_CHF -0.01373
AUD_CHF -0.010555
AUD_JPY 0.8835
AUD_JPY 1.1165
AUD_JPY 1.0055
AUD_JPY -1.3975
AUD_JPY -1.6915
But I don’t know how to do it.
Please can you help me?
Thanks
Francisco