Question

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R: subset() logical-and operator for combining conditions should be & not &&

I have a simple question, but I don’t know how to solve this…
I want to select all rows where value_1 > 0 and value_2 > 0.
Now I have this code:

dataOnBoth<-data[data$value_1 > 0,][data$value_2 > 0,]

When I head this data, ordering on log2_fold_change, I have This output:

gene_id        sample_1 sample_2 status   value_1 value_2 log2_fold_change
86  uc001aen.1       q1       q2 NOTEST 0.0619347       0    -1.79769e+308
150 uc001ahx.1       q1       q2 NOTEST 0.0432199       0    -1.79769e+308
186 uc001ajk.1       q1       q2 NOTEST 0.0854541       0    -1.79769e+308
251 uc001amf.1       q1       q2 NOTEST 0.0636211       0    -1.79769e+308
358 uc001are.3       q1       q2 NOTEST 0.3642040       0    -1.79769e+308
394 uc001ass.1       q1       q2 NOTEST 0.0196794       0    -1.79769e+308
        test_stat   p_value q_value significant
86  -1.79769e+308 0.4767020       1          no
150 -1.79769e+308 0.3960920       1          no
186 -1.79769e+308 0.0631033       1          no
251 -1.79769e+308 0.4428030       1          no
358 -1.79769e+308 0.1083640       1          no
394 -1.79769e+308 0.1489190       1          no

So R didn’t test the second condition…
When using the & to test both conditions, I receive 0 rows:

dataOnBoth<-data[data$value_1 > 0 && data$value_2 > 0,]

How do I select all rows where value_1 > 0 and value_2 > 0?

Answer 1

You need to use a single ‘&’:

dataOnBoth = data[data$value_1 > 0 & data$value_2 > 0,]

See this question for more details.