9,483 reputation
11840
bio website en.wikipedia.org/wiki/…
location United States
age 70
visits member for 3 years, 10 months
seen 16 hours ago

BS Mechanical Engr.
PhD CS(AI)
CS Prof (4yr)
Numerous consulting jobs.
15 yr at http://www.pharsight.com
Published book on CS & several articles
4 kids, 2 grand
Pilot(student)

P.S. The picture is a Beta-prime distribution. It shows the program speedup factors you can get if you see a problem twice in 2, 3, 4, and 5 samples.


Jan
17
comment How has an increase in the complexity of systems affected successive generations of programmers?
@PeterMortensen: I just emailed it to you (17mb). Remember, it's 20 years old.
Jan
16
comment How has an increase in the complexity of systems affected successive generations of programmers?
@MDMoore313: I scanned it, and could send you that. It's 17mb.
Jan
15
comment How has an increase in the complexity of systems affected successive generations of programmers?
@Jason: I plead ignorance of nimrod. What I look for in a DSL is if you write domain-specific programs in it, and a specific request or requirement comes along that's simple enough that you can either do it or not, then if you completely implement it, then you diff the source files before and after the implementation, the number of differences is small. (puff!)
Jan
14
comment How has an increase in the complexity of systems affected successive generations of programmers?
@Izkata and Peter: Yeah, I'm that oddball. FWIW, I put up a couple (extremely amateur) videos, in hopes of making it easier to understand. Random Pausing. Differential Execution. Cheers.
Jan
14
comment How has an increase in the complexity of systems affected successive generations of programmers?
@RobertHarvey: You're right, and my attempts to do that have not all been well received :)
Jan
14
comment How has an increase in the complexity of systems affected successive generations of programmers?
@PeterMortensen: Agreed. It's lonely. There's a word for that - Cassandra complex.
Nov
20
comment Jargon to describe unnecessary running of code?
@MichaelShaw: ... Now, 1 out of 2 interrupts show the problem, on average. It doesn't take many interrupts to see it. So you could call it a measurement, but it's a very poor measurement of the fraction of time. It's very precise evidence of what the problem is exactly. Does that help to explain the difference? That's just one example. Software is full of that kind of thing, if it's of any size.
Nov
20
comment Jargon to describe unnecessary running of code?
@MichaelShaw: Just to be specific, I've seen an app that takes about 60 seconds to start up. It happens to be spending about 50% of that time reading resources from dll files (which a CPU profiler will not see at all). Profilers that summarize function times will show many functions with high inclusive time. (Self time is useless.) Looking at that, you have no idea what the problem is. However, if you interrupt it a few times and each time understand the reason why (by reading the 20-level stack) you see it's doing it only for eye-candy on a splash screen. ...
Nov
20
comment Jargon to describe unnecessary running of code?
@DougM: The trouble with that is it leads people to think "I'm not a bad programmer, so I have no need to look for speedups." Speed problems are just like bugs - everybody makes them. The difference is - bugs say "FIX ME", while speed problems just lie there hoping you won't notice.
Nov
20
comment Jargon to describe unnecessary running of code?
@MichaelShaw: I use random pausing to find the problems, so I can remove them. That is not measuring. Measuring did not put the finger on the problems. Then I measure the overall result (not individual routines), to see how much I saved.
Nov
17
comment Jargon to describe unnecessary running of code?
@Masi: It is an important topic, and the tools that are being developed can't compete with the best tool that's been around forever, a debugger, and here's the math behind it. Most of the programming world is still under the false impression that the way to find inefficiencies is by measuring. All that can tell you is where they're not, not where they are. It leads people to be happy with finding small problems but missing big speedup opportunities.
Nov
7
comment What causes bad performance in consumer apps?
@Crashworks: Also, my first-ever YouTube video, on random pausing, is here.
Sep
2
comment Is it possible to compile a higher level language to readable C++?
@Jan: Good point. I wonder if teachers could say "In situation X, the options are Y or Z, and these are the pros and cons" so we minimize the situation where if you've got a hammer everything looks like a nail.
Sep
2
comment Is it possible to compile a higher level language to readable C++?
@Jan: I'm sure you're right. The problem I see all the time is people using features because they're "cool", not because they're needed, necessarily.
Aug
29
comment Is it possible to compile a higher level language to readable C++?
I agree that Lisp can do certain things that are hard in C++ (like closures). Do you need to do those things? Then since they are hard to do in C++, no matter how you get them into C++, automatically or manually, it will not be pretty. My suggestion: If you don't really really truly need those difficult things that Lisp can do, don't use Lisp. Get good at C++. If you must use those things, but you must code in C++, then figure out how to do it in C++. That's what separates the adults from the children in this business.
Aug
23
comment Why one would commit changes to version control every three minutes?
Just got a drive-by :)
Aug
15
comment What are examples of comments that tell you why instead of how or what?
@Jon: If the comment were not there, the reader can see what is happening, but has no idea why.
Jul
30
comment Are missed deadlines common in programming jobs?
+ Good answer, but having had some exposure to mechanical and civil engineering, it's amusing how programmers make facile comparisons to building bridges and other things, when they haven't the faintest idea how those are built.
Jul
23
comment Premature optimization in deciding how to optimize?
+ This describes so much sad experience.
Jun
18
comment Is there a comparative study of the memory consumption of programming languages runtimes, correlated with expressiveness and production bug ratios?
@haylem: I bow to an honest question. Good luck.