You can use the > operator to keep only values above 0. Assuming that your dataframe is called DF:
DF <- DF[DF$value_2 > 0,]
EDIT:
To keep rows where both columns are above 0, you can combine two expressions:
DF <- DF[DF$value_2 > 0 | DF$value_1 > 0,]
EDIT2: Here's the full example, including printouts. Creating the data frame:
gene <- c("ERCC-0003", "ERCC-0004", "ERCC-0009", "ERCC-00012", "ERCC-00013", "ERCC-00014", "ERCC-00016", "ERCC-00017", "ERCC-00019")
value_1 <- c(2.17523e+02, 1.54077e+03, 1.07257e+02, 4.08964e-02, 1.95994e-01, 6.20654e-01, 0.00000e+00, 0.00000e+00, 4.05462e+00)
value_2 <- c(2.62037e+02, 1.89043e+03, 1.31688e+02, 0.00000e+00, 1.92254e-01, 5.46050e-01, 0.00000e+00, 2.61275e-02, 5.89595e+00)
DF <- data.frame(gene, value_1, value_2)
DF
Output:
gene value_1 value_2
1 ERCC-0003 2.17523e+02 2.62037e+02
2 ERCC-0004 1.54077e+03 1.89043e+03
3 ERCC-0009 1.07257e+02 1.31688e+02
4 ERCC-00012 4.08964e-02 0.00000e+00
5 ERCC-00013 1.95994e-01 1.92254e-01
6 ERCC-00014 6.20654e-01 5.46050e-01
7 ERCC-00016 0.00000e+00 0.00000e+00
8 ERCC-00017 0.00000e+00 2.61275e-02
9 ERCC-00019 4.05462e+00 5.89595e+00
Keeping only rows with values above 0 in value_1 and value_2:
DF <- DF[DF$value_2 > 0 | DF$value_1 > 0,]
DF
Output:
gene value_1 value_2
1 ERCC-0003 2.17523e+02 2.62037e+02
2 ERCC-0004 1.54077e+03 1.89043e+03
3 ERCC-0009 1.07257e+02 1.31688e+02
4 ERCC-00012 4.08964e-02 0.00000e+00
5 ERCC-00013 1.95994e-01 1.92254e-01
6 ERCC-00014 6.20654e-01 5.46050e-01
8 ERCC-00017 0.00000e+00 2.61275e-02
9 ERCC-00019 4.05462e+00 5.89595e+00
EDIT3: My bad, the previous code used the & operator, which seems (rather curious to me) to work as "OR", omitting rows where value_1 OR value_2 were above 0, resulting in the incorrect removal of e.g. ERCC-00017. I changed the code to use the | operator instead, which seems to do what you want, namely removing rows where both values are above 0. Having not used R before, this is really unintuitive behaviour to me, as it's the complete opposite of how every other programming language (that I know of) works.