need two things: 1) to `group` the data and 2) a way to point to background
wells. Since grouping takes a bit practice until it becomes easy, I will
just say that you need to subtract background on each day, on each plate,
in each timepoint. The wells with no bacteria were encoded to have `uM =
-1` i.e. after appropriate grouping it comes down to: `OD = OD/OD[uM ==
-1]`. Input [data](doc/tasks/03_dat.csv) is the same as in step 3 above.
in each timepoint. The wells with no bacteria were encoded to have `uM = -1` i.e. after appropriate grouping it comes down to: `OD = OD/OD[uM == -1]`. Input [data](doc/tasks/03_dat.csv) is the same as in step 3 above.
And if you now plot everything exactly as in step 3 above, except having OD on y-axis, here's what [output](doc/tasks/04_out.pdf) should look like.
5. Constrain the OD at limit of detection. You might have noticed on the
