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Spartan Ideas is a collection of thoughts, ideas, and opinions independently written by members of the MSU community and curated by MSU Libraries

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Evaluating Expressions in CPLEX

There’s a feature in the Java API for CPLEX (and in the C++ and C APIs; I’m not sure about the others) that I don’t see mentioned very often, possibly because use cases may not arise all that frequently. It became relevant in a recent email exchange, though, so I thought I’d highlight it. As …

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R v. Python

A couple of days ago, I was having a conversation with someone that touched on the curriculum for a masters program in analytics. One thing that struck me was requirement of one semester each of R and Python programming. On the one hand, I can see a couple of reasons for requiring both: some jobs …

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A Java Container for Parameters

A few days ago, I posted about a Swing class (and supporting stuff) that I developed to facilitate my own computations research, and which I have now made open-source in a Bitbucket repository. I finally got around to cleaning up another Java utility class I wrote, and which I use regularly in experiments. I call …

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Indicator Constraints v. Big M

Way, way back I did a couple of posts related to how to model “logical indicators” (true/false values that control enforcement of constraints): Logical Indicators in Mathematical Program Indicator Implies Relation The topic ties in to the general issue of “big M” model formulations. Somewhere around version 10, CPLEX introduced what they call indicator constraints, …

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Naming CPLEX Objects

A CPLEX user recently asked the following question on a user forum: “Is there a way to print the constraints as interpreted by CPLEX immediately after adding these constraints using addEq, addLe etc.” The context for a question like this is often an attempt to debug either a model or the code creating the model. …

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How to Crash CPLEX

A question elsewhere on the blog reminded me that some users of the CPLEX programming APIs are not conscious of a “technicality” that, when violated, might cause CPLEX to crash (or at least throw an exception). The bottom line can be stated easily enough: modifying a CPLEX model while solving it is a Bozo no-no. …

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We Have Never Been Social

Last week, I had the pleasure of chatting with Bryan Alexander on his Future Trends Forum. We were primarily focused on Generous Thinking, but by way of having me introduce myself, Bryan asked what I’m working on this year. I mentioned that I’m in the early research phases of what might turn out to be a new …

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Summer 2019

I’m titling this post “Summer 2019” in part as a way of reminding myself, as firmly as possible, that the summer has begun, in order to get myself focused on a new set of priorities as quickly as possible. The transition from spring into summer has always been a bit of a challenge for me. …

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Randomness: Friend or Foe?

I spent a chunk of the weekend debugging some code (which involved solving an optimization problem). There was an R script to setup input files and a Java program to process them. The Java program included both a random heuristic to get things going and an integer program solved by CPLEX. Randomness in algorithms is …

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Enough Already!!

This was originally published at The Sports Column. ‘Enough Already!’ With Big Sports Salaries The elephant in the room is increasing income inequality—the outlandish incomes and escalating growth at the top of the income chain. Perhaps nowhere is that situation more evident than in athletics. Last month we saw two record-breaking salaries. The Phillies’ Bryce Harper signed for …

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MSU Research Update (video)

Remarks at a recent Michigan State University leadership meeting. MSU is currently #1 in the US in annual Department of Energy (DOE) and DOE + NSF (National Science Foundation) funding. There are ~30 institutions in the US with larger annual research expenditures than MSU, however in all but a few cases (e.g., MIT and UC …

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Interview with Genetic Engineering & Biotechnology News

  Polygenic Risk Scores and Genomic Prediction: Q&A with Stephen Hsu In this exclusive interview, Stephen Hsu (Michigan State University and co-founder of Genomic Prediction) discusses the application of polygenic risk scores (PRS) for complex traits in pre-implantation genetic screening. Interview conducted by Julianna LeMieux (GEN). GEN: What motivated you to start Genomic Prediction? STEVE …

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Pseudocode in LyX Revisited

This post is strictly for users of LyX. In a previous post I offered up a LyX module for typesetting pseudocode. Unfortunately, development of that module bumped up against some fundamental incompatibilities between the algorithmicx package and the way LyX layouts work. The repository for it remains open, but I decided to shift my efforts …

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Failures to Listen

One year ago today, Rachael Denhollander addressed the Ingham County court in Michigan, her abuser, and the institutions that failed to protect her and her #SisterSurvivors. Listen again to part of what she said on January 24, 2018: This is what it looks like when institutions create a culture where a predator can flourish unafraid and …

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Attitude of Possibility

Putting together a 1,000-piece jigsaw puzzle seems an appropriate metaphor for the challenges ahead of us as a human family. This one took my wife, Ellen, and me, about a week of coming and going. It was a good activity for some frigid, snowy days and evenings. We didn’t count the hours, we simply hovered …

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Guessing Pareto Solutions: A Test

In yesterday’s post, I described a simple multiple-criterion decision problem (binary decisions, no constraints), and suggested a possible way to identify a portion of the Pareto frontier using what amounts to guesswork: randomly generate weights; use them to combine the multiple criteria into a single objective function; optimize that (trivial); repeat ad nauseam. I ran …

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Guessing Pareto Solutions

One of the challenges of multiple-criteria decision-making (MCDM) is that, in the absence of a definitive weighting or prioritization of criteria, you cannot talk meaningfully about a “best” solution. (Optimization geeks such as myself tend to find that a major turn-off.) Instead, it is common to focus on Pareto efficient solutions. We can say that …

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Binary / Integer Conversion in R

I’ve been poking around in R with an unconstrained optimization problem involving binary decision variables. (Trust me, it’s not as trivial as it sounds.) I wanted to explore the entire solution space. Assuming \(n\) binary decisions, this means looking at the set \(\{0,1\}^n\), which contains \(2^n\) 0-1 vectors of dimension \(n\). For reasons I won’t …

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Food Fraud Education Schedule – Quarterly Update + MOOCs Now On-Demand

REGISTRATION AND COURSES OPEN: MSU Food Fraud MOOC programs – Free Food Fraud Overview Food Fraud Audit Guide Food Defense Audit Guide Food Fraud VACCP Implementation (Food Fraud Vulnerability Assessment FFVA & Food Fraud Prevention Strategy FFPS Development) Each MOOC is offered monthly, with the content available on-demand.  Live lecture webinar updates are offered semiannually. …

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Precision Genomic Medicine and the UK

I just returned from the UK, where I attended a Ditchley Foundation Conference on machine learning and genetic engineering. The attendees included scientists, government officials, venture capitalists, ethicists, and medical professionals. The UK could become the world leader in genomic research by combining population-level genotyping with NHS health records. The application of AI to datasets …

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The Future of Genomic Precision Medicine

As I mentioned in this earlier post, I’ll be in the UK next week for a Ditchley Foundation conference on the intersection of machine learning and genetic engineering. I’ll present these slides at the meeting. The slides review the rapidly evolving situation in genomic prediction, focusing on disease risk predicted using inexpensive genotyping. There are now …

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Threads and Memory

Yesterday I had a rather rude reminder (actually, two) of something I’ve known for a while. I was running a Java program that uses CPLEX to solve an integer programming model. The symptoms were as follows: shortly after the IP solver run started, I ran out of RAM, the operating system started paging memory to …

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Two Books – Real Gifts

I have a pile of about 10 books I’m wading through, but two are of special note as I write this. As I noted in my last blog of 2017 I have the privilege of reading, and especially of reading books. For the past few years I’ve read on average between 20-30 nonfiction works cover-to-cover per year. …

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On Fear, Parades of Horribles, and Emotionally Potent Oversimplifications in Tribal Rights Litigation

  Will the state of Oklahoma revert back to the Indians? Will tribes veto non-Indian land use decisions? Will thousands of state prisoners go free? Will non-Indians have to give back their lands to Indians? In the last few years, in cases out of Oklahoma, Wyoming, Michigan, Washington, and elsewhere, advocates for states and non-Indian property owners have invoked …

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IceCube: neutrino astronomy in Antarctica

Tyce DeYoung (MSU Department of Physics and Astronomy) colloquium on high-energy astrophysics and exploration of the high-energy universe with the IceCube neutrino detector at the South Pole. Several MSU professors are part of the IceCube collaboration. I predict very exciting developments in neutrino astronomy in the coming decade ;-) The situation is similar to that …

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Reading Soccer

For almost a decade I’ve been involved with the Football Scholars Forum, an online book club that TV wordsmith Ray Hudson labeled “the soccer think tank.” I also like to think of it as an intellectual pick up game. An informal space to read, reflect, try new things, network, learn, and engage in thoughtful conversations with fútbologists around the …

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Living Values

In the open letter we wrote to the College of Arts & Letters community in January 2018, we promised to look critically at ourselves, recognize our failures, and rebuild the trust that is required of us. This commitment has led to an intense period of critical self-reflection in the Dean’s Office and across the College in …

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The Quantum Theory of Fields

Excerpt from Sidney Coleman’s Erice lectures. The period he describes just predates my entry into physics. This was a great time to be a high-energy theorist, the period of the famous triumph of quantum field theory. And what a triumph it was, in the old sense of the word: a glorious victory parade, full of …

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Of Typewriters and Permutations (II)

This continues my previous post about the problem of optimally laying out a one-dimensional typewriter keyboard, where “optimally” is taken to mean minimizing the expected amount of lateral movement to type a few selected books. As I noted there, Nate Brixius correctly characterized the problem as a quadratic assignment problem (QAP). I’ll in fact try …

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Time to Empty Your Pockets

I just made my self read the nine page “Executive Summary” of the recently (November 14) released Providing for the Common Defense: The Assessment and Recommendations of the National Defense Strategy Commission . It was all I could do to keep from gagging. I won’t put myself through the full 116 pages, especially as I scanned the …

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