Is there a quick way to get the proportion/percentage of each item in a group? right now, I first compute the sum of the values by group, and then merge this total table to the original table, and then compute the proportion. Does Q have a quick function to compute this?
day week item proportion
mon 1 2 20%
tue 1 7 70%
wed 1 1 10%
mon 2 1 25%
tue 2 2 50%
wed 2 1 25%
currently, I would do:
total: select total: sum item by week from table;
out: update proportion: item%total from table lj `week xkey total;
You can use fby to do this in one query:
q)table:flip`day`week`item!(`mon`tue`wed`mon`tue`wed;1 1 1 2 2 2;2 7 1 1 2 1)
q)update proportion:item % (sum;item) fby week from table
day week item proportion
------------------------
mon 1 2 0.2
tue 1 7 0.7
wed 1 1 0.1
mon 2 1 0.25
tue 2 2 0.5
wed 2 1 0.25