====== Implement aging using a map ======
If you need to age a stock by 1 year you can create a map which moves all stock up 1 in the age sequence and bins the last 2 years with the following code:

<code>
integer $firstAge = 0
integer $lastAge = 100

local eafrToea[ea,eafr] = create (; dim=SEQ;age:$firstAge:$lastAge:1;year, \
	dim=SEQ;ageFr:$firstAge:$lastAge:1;year)
eafrToea[ea,eafr] = insert (extract (diag (1.0; \
	dimFrom1=eafrToea[ea,eafr]); \
	age:+0..-1); \
	1->age:+1, 2->ageFr:+0)
eafrToea[ea,eafr] = insert (1.0; age:-0, ageFr:-0)

table (eafrToea[ea,eafr]) ! Just to prove to yourself it worked, comment it out later
</code>

Now you can just apply the map to your stock (not the change of sequence name just before the map!):
<code>
local agedStock[upperDims,ea] = map (changeseq (stock[upperDims,ea]; \
   dim=age, name=ageFr), \
   eafrToea[ea,eafr])
</code>