search for: sum_id

...be chosen so that this is satisfied. How to do this in R? Without the coupling the least-squares formulation would seek coefficients a_p and b_p to minimize: sum_p(sum_p((s_id,p - a_p t_id,p + b_k)^2)). Minimization at each p is independent. With coupling, there would be an additional term: sum_id((sum_p(vp)-h_id)^2) where vp is a function of a_p t_id,p + b_k and of t_id. The functions for vp are nonlinear, but if necessary with some work it should be possible to get a linear function that is good enough. Also, not all stations have values at all pressures. Thanks, Carlisle -- Willia...

...themselves, or be in terms of Symbol-indexed hashes, or both. Any code inside Arel and ActiveRecord that instantiates SqlLiterals would need to add appropriate calls to register its literals at load time. For example, arel-2.2.1/lib/arel/expressions.rb would call, Arel.register_sql(''sum_id'', ‘max_id’, ….) In addition, application code itself could register literals at load time, to white-list custom statements, as in class CustomersController < ApplicationController Arel.register_sql {:customer_by_id => "name = ?"} def show @customer = Customer.where(:cu...