9,038 reputation
11838
bio website en.wikipedia.org/wiki/…
location United States
age 69
visits member for 3 years, 7 months
seen 21 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
15
awarded  Nice Answer
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.
Jan
14
answered How has an increase in the complexity of systems affected successive generations of programmers?
Dec
2
awarded  Announcer
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
19
awarded  Nice Answer
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
25
revised How to find bottlenecks in an application?
added 446 characters in body
Sep
25
revised How to find bottlenecks in an application?
added 998 characters in body
Sep
25
answered How to find bottlenecks in an application?
Sep
18
revised Optimization of time-varying parameters
added 22 characters in body
Sep
18
revised Optimization of time-varying parameters
added 62 characters in body
Sep
18
answered Optimization of time-varying parameters
Sep
17
awarded  Yearling