Excluindo colunas no R

log(), 

log(ANP_COMBUSTIVEIS[,c(-1,-7)])

PRECO_REV_ETANOL PRECO_REV_GASOLINA PRECO_REV_GLP PRECO_REV_GNV PRECO_REV_DIESEL
1 0.009257021 0.5196268 2.844613 -0.31471074 -0.18717331
2 0.014198719 0.5370780 2.873706 -0.29988962 -0.16251893
3 0.026154957 0.5411608 2.884778 -0.30042965 -0.15059036
4 0.038354954 0.5758828 2.930244 -0.26748737 -0.10725119
5 0.032079893 0.5767257 2.937520 -0.24910259 -0.09695153
6 0.028490270 0.5736314 2.928181 -0.24718013 -0.09673119
7 0.018821754 0.4621605 3.084173 -0.24654013 -0.12386399

log(ANP_COMBUSTIVEIS[,c(-1,-7)])

 PRECO_REV_ETANOL PRECO_REV_GASOLINA PRECO_REV_GLP PRECO_REV_GNV PRECO_REV_DIESEL

1 0.009257021 0.5196268 2.844613 -0.31471074 -0.18717331
2 0.014198719 0.5370780 2.873706 -0.29988962 -0.16251893
3 0.026154957 0.5411608 2.884778 -0.30042965 -0.15059036
4 0.038354954 0.5758828 2.930244 -0.26748737 -0.10725119
5 0.032079893 0.5767257 2.937520 -0.24910259 -0.09695153
6 0.028490270 0.5736314 2.928181 -0.24718013 -0.09673119
7 0.018821754 0.4621605 3.084173 -0.24654013 -0.12386399

c(-1:-5)

[1] -1 -2 -3 -4 -5