show rna_with_missing_values creation

episodes/30-dplyr.Rmd

@@ -609,16 +609,13 @@ Let's imagine that for some reason, we had some missing expression values for so
 genes in certain samples. In the following fictive example, the gene Cyp2d22 has only
 one expression value, in GSM2545338 sample.
 
-```{r, purl=TRUE, echo=FALSE}
+```{r, purl=TRUE}
 rna_with_missing_values <- rna %>%
   select(gene, sample, expression) %>%
   filter(gene %in% c("Asl", "Apod", "Cyp2d22")) %>%
   filter(sample %in% c("GSM2545336", "GSM2545337", "GSM2545338")) %>%
   arrange(sample) %>%
   filter(!(gene == "Cyp2d22" & sample != "GSM2545338"))
-```
-
-```{r, purl=TRUE}
 rna_with_missing_values
 ```