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Applied Mathematical Programming (1977)

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Re: Applied Mathematical Programming (1977)

#31
post #28

Earlier quoted context omitted.

You should have tried wall street. At this point they are the real supporters of mathematicians. We had optimization problems everywhere and had physics PhDs reinventing mathematical algorithms and keeping things “proprietary”. Right now i work in a startup that essentially writes optimization routines for portfolio problems. I will blame your phd advisor.

Wall Street? I was in NY and close enough to NYC. I'd just published a paper in anomaly detection in complex systems, gave a talk at the main NASDAQ server farm, and later at Morgan Stanley. No real interest. Sent a copy of my anomaly paper to a hedge fund, got an interview, was asked by one of their junior people "If know the correlation between A and B and that between B and C, what about A and C"? Okay, maybe: Sta…

> I was naive. Knew much more about math and computing than people and personality.

Do you think not learning math would have helped you understand people at a younger age? It sounds like you just needed time to grow socially and in practicality. For most people on this forum, that’s a challenge regardless.

Re: Applied Mathematical Programming (1977)

#32
post #18

Earlier quoted context omitted.

Is Binet's formula really that practical a way to calculate the Fibonacci numbers (except asymptotically)? The problem is, you have this nice clean expression, but you'd still have to implement a bunch of fancy arbitrary-precision arithmetic to approximate the golden ratio through Newton's method. In other words, the formula gives much more information about the structure of the Fibonacci numbers than their actual va…

Once you have postulated BigInt as available, the mathematician is going to make a rational approximation for phi using the continued fraction expansion that they know by heart (because of its “simplicity”).

Calculating φ from its continued-fraction expansion is equivalent to just iterating the Fibonacci sequence normally, since its convergents are precisely the ratios between the Fibonacci numbers. At that point, it's totally redundant to use Binet's formula on the approximation, since you have the values already!

If you want to beat the O(n^2) runtime of the trivial iteration, you pretty much have to use Newton's method for φ, exponentiation by squaring on the matrix form, or another method with faster-than-linear convergence.

Re: Applied Mathematical Programming (1977)

#33
post #23

Earlier quoted context omitted.

The point of the post is that in my long experience there was not much about optimization that in any significant practical career sense was "applied", i.e., no jobs even to keep one from living on the streets, far from a career to buy a house and support a family. The point about my Ph.D. with a lot in optimization is that I was quite well qualified in the field, but even with all those qualifications "applied" was…

Sounds like you opened up the newspaper and scanned for “mathematician”. Leveraging phd research into a great job is a tough. Re-skilling into a normie engineer/technician/analyst, is not. My point is not to criticize your job hunting skills, it’s to suggest that this an undue psychological burden in your life and is perhaps masking other causes and personal challenges.

Naw: The WaPo period was before my Ph.D. The ads were for computing -- math not mentioned. For some years, the career was computing but with some math, e.g., the FFT (fast Fourier transform), ....

I never wanted the Ph.D., what I learned there, the research I did there, to be the basis of a career. Instead, before the Ph.D. I had a good career going with computing and, at times a crucial help, some math, and went for the Ph.D. ONLY to do better at THAT career. For my career, the day I entered the Ph.D. program was a BIG step down, and what I'd learned about optimization was, in a word, WORTHLESS.

My main point here is on the word "applied" for optimization: I was well qualified, and happened to publish some research in optimization, but discovered that "applied" optimization was not the basis of a good career. Here I'm just reporting that fact. I doubt that there is still any real career opportunity in "applied" optimization.

So, a book title with "Applied" Optimization is to me a outrage.

I wasn't stuck on "optimization". For a while worked in the first wave of AI (artificial intelligence via the Rete algorithm). Then published in mathematical statistics. I was perfectly willing to mow grass, shine shoes, ..., do anything that would support me financially, be reasonably safe, and not seriously illegal but discovered that "Ph.D." on the resume blocked any such. Thought about taking "Ph.D." off the resume but was afraid that I'd get into trouble due to the gap in time.

Here my point, complaint, warning, contribution to others, is: My long experience was that there is nearly no career in "applied" optimization. A second point could be, outside of academics, a Ph.D. can hurt your career. Try leaving it off your resume. A Ph.D. might be worse for your career than a felony conviction; no joke (my legal history is totally clean).

In life, we are forced to make important decisions without good information. In my career, at times I did well, and at times I didn't.

E.g., by middle school it seemed accepted and true that education helps, more education helps more, education in the STEM fields is the best, a Ph.D. is the best education, and, thus, a Ph.D. in a STEM field should be really good, e.g., easily enough to buy a house and support a family.

Truth: Nope, too simple. I couldn't take care of my wife, kitty cats, get a job, any job, at all, ANY job, got run out of the house by the Sheriff with guns.

With a BS "With Honors" in math, I got strongly recruited. With a Ph.D. in applied math, including optimization, I got strongly rejected.

Yup, it hurt. I was manipulated, lied to, and hurt.

"psychological burden": Maybe those are the right words. But millions of people have suffered worse, e.g., The Great Depression, wars, Covid in the family, and much more, and still did well.

Don't know the solution in general.

For me, now, still good in math and computing, with .NET, etc. got a Web site, with some math at the core, running easily enough, and intending to go live, get some viewers, run simple ads (standard sized rectangles), and make some money. In this, want to remain anonymous and not be a public person.

And want to OWN the business. Have someone list what papers I need to file for a business, an LLC, etc. Get an accountant. Get and receive revenue. In simple terms, add up the expenses and keep the rest. Eventually sell the business and pursue, say, mathematical physics.

Re: Applied Mathematical Programming (1977)

#34
Currently doing this Discrete Optimization course by Pascal Van Hentenryck and it is great: https://www.coursera.org/learn/discrete-optimization

It has only week on Linear Programming which is nicely done but I think the real value is that it starts with the much more playful Constraint programming and focuses on intuitions and keeping you both entertained and trained which is really hard to do.

The course comes with assignments and the whole thing sort of has a Advent of Code flavor (I kind of have a half baked plan on make this year discrete optimization my AOC theme).

Not strong on the modeling part/business motivation.

Re: Applied Mathematical Programming (1977)

#35
post #19

"Applied ..."? On the Optimization Ph.D. qualifying exam, got a "High Pass" and the best score in the class. In optimization answered a question in the Kuhn-Tucker constraint qualifications and had the paper accepted quickly in Mathematical Programming . Taught linear programming in a well-known business school for 5 years. NYC had a few users, in a loose group, of linear programming but were not very good at it. Som…

> A fact of life: Nearly always people with money, power, and optimization problems don't understand optimization, fear and resent those who do, and choose just to avoid the subject. Food for thought: the solution to real-world optimization problems is often dictated by constraints instead of optimal values. This means that if you fail to understand the constraints, or even fail to identify them, then whatever your s…

Naw, you list some mistakes, but I didn't make any of those.

> From your anecdotes you were the one tasked with clarifying things to them. From the sound of it, you didn't accomplished that, and it was unclear to stakeholders whether your output even provided any value worth keeping.

First, for any application, there has to be some practical interest. My view, there isn't much. The schools of math, engineering, and business have given optimization a big push, back at least to Dantzig, but from my long experience the interest was and is still just too low for "applied" optimization to have much in applications.

Cases: Sure, there has been a professor at Princeton who applied optimization to oil refining: What mixture of crude oil to mix into the refinery and what mixture of refined products to take out. Maybe a few, large livestock operations actually do run some diet problem solutions. And can use 0-1 optimization for Sudoku problems? What path for picking orders in a big warehouse, for Amazon or Walmart? A simple traveling salesman problem, and for a good enough solution build a minimum spanning tree and walk around that -- maybe they are doing that already. Assembly line balancing: Assign workers to positions to maximize the speed of the slowest worker assignment. Is anyone actually doing that? Even if they are, the solution is quite simple. Yes, a start on P vs NP was at Bell Labs designing networks. So, maybe with the Internet there are still valuable applications? Considered that. Got an interview at a company trying that. They were impressed by what I'd done at FedEx, but they were nearly dead and, I suspect, soon died. Maybe with big logistics, ocean, rail, trucks, warehouses, there are some big logistics problems where optimization could save a lot -- applications enough for careers? Better than grass mowing? When I got my Ph.D., the Chair of my dissertation orals committee was a big name in logistics -- saw no evidence of significant interest in applications. No ones in the halls. Phone not ringing. No suggestions of contacts for me.

Look, when there is a big need, ESPECIALLY when there is big money involved, it soon gets obvious, and the US economy gets to it right away. In that, "applied" optimization is not hot, warm, or much above freezing.

Right, you are mentioning formulation:

(1) They had already formulated a 0-1 optimization problem. It had 40,000 constraints and 600,000 variables. They had tried the then popular simulated annealing, ran for days, and quit. So, the formulation was done and not mine.

I worked hard, with the IBM OSL (optimization subroutine library), did 900 primal-dual iterations, Lagrangian relaxation, got a feasible solution within 0.025% of optimality, within two weeks, for free, a free sample, and never heard from them again. They resented and were afraid of my success.

(2) Another company was working a little more generally in optimization. Had a crude heuristic running. On some of their problems, 0-1, linear, again was successful with the OSL, and got only insults and resentment. Continued on, gave them a nice formulation, better than their heuristic, and path through optimization, and got fired. They'd hired me and wanted to fire me before 6 months was up. They were not very good with linear programming at all, and I was a LOT better at what they were doing in the formulation, math, and computing, and their reaction was they didn't want me for competition.

(3) In a military group, did well with some non-linear optimization (their formulation). Then they had a challenging strategic problem. I did a formulation of a Monte-Carlo solution and wrote and ran the code (used an Oak Ridge random number generator I'd programmed in assembler). They called in a famous probability professor for a review. His remark was that there was no way the Monte-Carlo could "fathom" the tree. He was right; the tree was huge. But each trial of my Monte-Carlo yielded at each point in time a random variable on 0-15, and the law of large numbers applied right away. It wasn't D-day, but suppose it was: The tree of possibilities was enormous, but the, say, number of Allied soldiers killed was, what, 0-200,000. So, each trial give a random variable value at, say, each second, for, say, 48 hours -- the law of large numbers applies and could tell Ike the distribution of number of deaths, the expected values, the median, the variance for each second of the 48 hours. Passed the review. One guy there used my random number generator on one of his old problems, got significantly different results, was afraid, said "I don't want you in the center of all my projects", and I got ignored on the way to being fired.

(4) At FedEx, had written a program that showed the BOD that the program made the fleet scheduling easy enough and saved the company. So, to do better, formulated a set covering direction. Savings? 1% would have been $millions a year. The founder, COB, CEO wrote a memo making that my project, but my boss, a Senior VP, said that there was no money in the budget for me; I'd been commuting between Memphis and Maryland where my wife was in her Ph.D. program; the stock promised in three weeks was very late; and I went for a Ph.D.

Actually another student at another school ran with my set covering formulation for his dissertation.

The high level, overview, simple fact of life, is as I described: There just is no real career in "applied" optimization. That horse is nearly dead and should not be further flogged. Millions of US families have a house, stable marriage, and healthy children, and I'd believe that fewer than 20 of those families are supported by careers in "applied" optimization -- maybe 0 families.

Re: Applied Mathematical Programming (1977)

#36
post #24

Earlier quoted context omitted.

Yup. Applied Optimization 101: For decisions in life and career, avoid the applied math approach to optimization. In particular, except maybe for some work in US national security, don't try to have the applied math of applied optimization for a career. Don't spend a lot of time studying optimization. Later might be able to be the founder, COB, CEO of a startup where some math is a big advantage.

> Yup. Applied Optimization 101: For decisions in life and career, avoid the applied math approach to optimization. It pains me to say this, but might it ever crossed your mind that the problem does not lie in applied mathematics of even optimization? We need soft skills to push the output from hard skills, and interacting with decision-makers requires people skills, not hard skills. If you can't communicate with som…

Fine. But I'm still not finding the private planes, yachts, mansions, or even houses with wife and children of people with careers in "applied" optimization. Computing, startups, venture capital, lots of careers. "Applied" optimization? In the years after my Ph.D., I didn't hear of them. As I was teaching optimization in a business school, the phone didn't ring. The phone did ring for some statistics, one from a company with sales districts and one from a law firm.

Re: Applied Mathematical Programming (1977)

#37
post #19

"Applied ..."? On the Optimization Ph.D. qualifying exam, got a "High Pass" and the best score in the class. In optimization answered a question in the Kuhn-Tucker constraint qualifications and had the paper accepted quickly in Mathematical Programming . Taught linear programming in a well-known business school for 5 years. NYC had a few users, in a loose group, of linear programming but were not very good at it. Som…

Bro, you spend a really long time getting great at this and from the bottom of my heart I feel your pain and believe we need to improve a lot as a society to take advantage of talents like you better. Thanks for investing so much time to it, I share your sadness for your wife and hope you get ao much good as you tried to bring to the world, man

Simpler than that: For "applied" optimization, much of a career, many applications, f'get about it.

I was naive, manipulated, and fooled. Now on the OP, there is a book title with "Applied Optimization", and I'm outraged.

So: "Always look for the hidden agenda."

Re: Applied Mathematical Programming (1977)

#38
post #28

Earlier quoted context omitted.

Wall Street? I was in NY and close enough to NYC. I'd just published a paper in anomaly detection in complex systems, gave a talk at the main NASDAQ server farm, and later at Morgan Stanley. No real interest. Sent a copy of my anomaly paper to a hedge fund, got an interview, was asked by one of their junior people "If know the correlation between A and B and that between B and C, what about A and C"? Okay, maybe: Sta…

> I was naive. Knew much more about math and computing than people and personality. Do you think not learning math would have helped you understand people at a younger age? It sounds like you just needed time to grow socially and in practicality. For most people on this forum, that’s a challenge regardless.

About people in math and the more technical parts of computing, I've guessed that poor socialization has played a role.

But when my career was okay, it was in computing, and I did well enough in the socialization.

Can consider these and those issues, but my experience was that "applied" optimization, as in the book title in the OP here, was too near the empty set.

It isn't just me: My professors in applied math and the ones in optimization were not getting much if anything in consulting. I've been recruited and hired, but never for optimization.

Here I'm trying to do a service to the readers: Be very careful about the idea that there is significant career help via "applied" optimization.

Re: Applied Mathematical Programming (1977)

#39

Has this been updated since 1977? Because the field and tools and even the view points have changed a ton.

Agree, I‘d say also the term „mathematical programming“ sounds really old school and never was that fitting to begin with.

„Learning how to formulate problems as integer/linear programming ones“, as another commenter put it, works great if it‘s a natural fit and sure is fun for idk 7th grade math text problems I guess but OTOH squeezing realistic problems into systems of hundreds of equations (or more if dealing with linearizations of inherently non-linear/concave/multi-step problems) to satisfy tool idiosyncracies calls for additional tools in your arsenal.

Re: Applied Mathematical Programming (1977)

#40
Just yesterday I sketch a solver for a board game: "Search for planet X".

The objective of the game is to figure out what kind of planets are hidden in sector of the boards using clues like: "There are 2 comets between secotr 3 and 7" or "No comet is next to an asteroid ".

Sketching the solver was incredibly fun and rewarding!

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