Displaying 1 result from an estimated 1 matches for "un_insect".
2012 Sep 18
2
Formula in a data-frame
...sediment 1 0.30
7 Schizodon sediment 1 0.90
8 Astyanax terrestrial_insect 1 0.10
9 Astyanax vegetal 1 0.85
10 Astyanax aquatical_insect 1 0.05
11 Astyanax vegetal 1 0.90
12 Astyanax un_insect 1 0.85
for each specie, I have to calculate a food item importance index, that is:
Fi x Vi / Sum (Fi x Vi)
Fi = percentual frequency of occurrence of a food item
Vi = percentual volume of a food item
So, using ddply (plyr) function, I was able to calculate the total
frequency of oc...