I am trying to keep only the numerical values on the surface column: 0,01 0,10 0,02 0,17 and so on until the end. Any ideas? Thanks
df <- data.frame(
stringsAsFactors = FALSE,
DATE = c("2021-08-07","2021-08-01",
"2021-07-31","2021-07-29","2021-07-22","2021-08-07",
"2021-08-06","2021-08-01","2021-08-01","2021-07-26",
"2021-07-21","2021-07-09","2021-07-05","2021-08-01",
"2021-07-25"),
SURFACE = c("OTRAS:0,01 HA.;",
"MATORRAL:0,10 HA.;","MATORRAL:0,02 HA.;",
"PASTO:0,17 HA. PASTOS Y MALEZA;","AGRICOLA:0,01 HA.;",
"MATORRAL:0,01 HA. MATORRAL;","MATORRAL:0,11 HA.;","PASTO:0,04 HA. PASTO;",
"ARBOLADO:0,01 HA. PINOS;","ARBOLADO:1,91 HA. ROBLE, PINO;",
"MATORRAL:0,01 HA. BREZO;","MATORRAL:0,50 HA.;",
"MATORRAL:0,05 HA. ZARZAS;","MATORRAL:1,50 HA.;",
"PASTO:0,70 HA. PASTO Y ZARZAS;")
)