How to achieve the goal "only genes with non-zero expression values in at least half of the sample type were kept"

Question

[zhangzd168]

I am a freshman in the field of bioinformatics analysis. I have downloaded the TCGA RNA seq Counts data for further analysis. The first step I want to do is screening only genes with non-zero expression values in at least half of the sample type like some papers do. But I don't know how to achieve this in R. Thank you!

[jordi.planells]

Next time, try to google the question. When you google "x columns greater than zero", the first solution that appears is this, that is exactly what you are looking for.

[zhangzd168]

Thank you so much!