How to cite only part of a vector in an equation?

Hi,

I am working on a health study. I have the daily contaminant levels in grinking water, for a month long period, for three different communities. I am trying to tabulate people's exposure based on how long they drank the water. So, if JaneDoe lived in Town A from 1/1/12-1/5/12 and then lived in Town B from 1/6/12-1/31/12, her level of exposure would be....

The question is how do I cite only part of a vector based on a date range? This is a population study of several thousand people so I can't manually call the date ranges for each participant in the study... The code would be something along the lines of:

if town=TownA,

then ....cite this part of TownA's contaminant vector, but on ly for the date range in wich JaneDoe lived there....the muchy part I don't know how to code:[

Thanks for any thoughts on this!

Answer 1

[Stephan]

One possible way:

You could use findgroups in combination with splitapply. For example, a JaneDoe group would be a member of the corresponding group regardless of the cities in which they were staying, and a function can be applied to these group members so that it is comparatively easy to obtain this information.

An example for understanding can be found here: https://de.mathworks.com/help/matlab/ref/findgroups.html#buxwasl

Another possible way:

Try to tackle this with groupsummary which also allows to make calculations on grouped data.