Csa on Harlan D. Harris

making meat shares more efficient with R and Symphony

harlan@harris.name (Harlan Harris) — Mon, 09 May 2011 01:01:01 +0000

In my previous post, I motivated a web application that would allow small-scale sustainable meat producers to sell directly to consumers using a meat share approach, using constrained optimization techniques to maximize utility for everyone involved. In this post, I’ll walk through some R code that I wrote to demonstrate the technique on a small scale.

Although the problem is set up in R, the actual mathematical optimization is done by Symphony, an open-source mixed-integer solver that’s part of the COIN-OR project. (The problem of optimizing assignments, in this case of cuts of meat to people, is an integer planning problem, because the solution involves assigning either 0 or 1 of each cut to each person. More generally, linear programming and related optimization frameworks allow solving for real-numbered variables.) The RSymphony package allows problems set up in R to be solved by the C/C++ Symphony code with little hassle.

making meat shares more efficient

harlan@harris.name (Harlan Harris) — Mon, 09 May 2011 00:00:00 +0000

A personal interest I have is the ethical and sustainable production of food. I’ve been a member of and helped run Community Supported Agriculture groups, and my wife and I currently purchase the majority of our meat from a group of upstate NY pastured-livestock producers who sell their products through CSAs. It’s an ala-carte business model, where I place an order on a website, and the next week I pick up the frozen products cut and packaged as if for retail.

Savory and sweet, pears and beets

harlan@harris.name (Harlan Harris) — Fri, 23 Oct 2009 00:00:00 +0000

Hah, it rhymes! The fall haul (hah!) from the CSA inevitably means two things, root vegetables and ungodly numbers of pears. I love root vegetables, but tend to find pears to be pale imitations of apples. But when poached in red wine, or cooked with butter and sugar, pears can have some redeeming value. Recently, for the cooking club, I teamed up to make a dessert with the theme “Fall Harvest.” We were inspired by a recent recipe from the late, lamented Gourmet magazine, Beet and Pear Napoleons with Ginger Juice Vinaigrette. Roasted beets layered with pears, with flavors of ginger, citrus, tarragon, and poppy. In fact, we were so inspired by the dish, that we made it too, and started the dinner with an amuse of the original recipe: