Scale counts in a robust way against sd == 0
scale_robust(y)
[Mangiola and Papenfuss., 2020](https://joss.theoj.org/papers/10.21105/joss.02472)
A scaled and centred numerical array
Mangiola, S. and Papenfuss, A.T., 2020. "tidyHeatmap: an R package for modular heatmap production based on tidy principles." Journal of Open Source Software. doi:10.21105/joss.02472.