Xah Programing Blog Archive 2016-05
xubuntu system tray icons missing
in Ubuntu 14.04, when running xfce (xubuntu), the system tray (notification area) icons is missing. That is, you don't see your internet connection status, sound volume, etc.
the problem is Ubuntu Unity's “indicator plugin”. It is some kinda replacement, but doesn't work well. Kill it, and icons will show in your old system tray.
to find all the process fullname, do
grep -ef | grep indicator
then, killall indicator-application-service
there are few others, starting with “indicator-”.
goto control panel, “Sessions and Startup”, in the autostart tab, uncheck the Indicator stuff.
Linux: What's Zeitgeist, How to Uninstall It
in Ubuntu linux, there's this Zeitgeist daemon. It logs your activities, for the same reason you don't want to be on Windows.
OCaml Tutorial: Function (rewrite. For beginner. My learning notes.)
amazon $50 tablet
amazon is selling tablets for $50. Buy at amazon
must be some kinda theory of economy. like, suck u in first, than make u do.
why syntax is more important than semantics
- 1. xah's edu corner extempore! episode 20160621920160700 why syntax is more important than semantics!
- 2. it's popular among hackers, the notion that semantics is more important than syntax. Even comp sci professors have said so, in textbooks.
- 3. IDIOTS
- 4. if you've studied history of math notations, you'll know. The notation, leads your perspective, and future direction on the subject.
- 5. for example, if lisp not parens, lisp macro would not have developed. if unix shell used lisp syntax, pipe | will not have developed.
the guy who started the idiotic chant among hackers that semantics is more important than syntax, is probably Matthias Felleisen.
xfce vs lxde
after many back and forth over the years, i really want to like lxde, but prefer xfce.
pros of lxde: more energy efficient than xfce. GUI simpler and functional. Things Just work. Doc is excellent.
xfce you have to diddle a lot, things don't work, confusing UI, incomplete or non-existent doc.
lxde major problem: no display composition = sometimes tear＆freeze, drag image is opaque, this is a problem, not just prettiness issue.
lxde major problem 2: No key to switch window of current app (and no, can't be easily scripted neither).
Programing Language Tutorials Index
now phone friendly (that is, display well in small screen). Best there are JavaScript, then emacs lisp then python.
https://plus.google.com/+XahLee/posts/6s4MQHp363s
xfce window focus bug
lots focus bug mouse hover to raise window, in xfce ubuntu 14.04. upgrading to xfce14.12, then you got wmctrl problem. 4 hours wasted.
here's the detail.
Activating a window from the taskbar doesn't focus it when 'focus follows mouse' https://bugs.launchpad.net/ubuntu/+source/xfwm4/+bug/1292122
now, its supposedly fixed. See: http://git.xfce.org/xfce/xfwm4/commit/?id=1a20a88
so, now you upgrade xfce to 4.12. Linux: How to Upgrade Xfce
but now, there's wmctrl problem. That is,
when you use the wmctrl tool to switch window wmctrl -xa emacs, it won't focus, only raise.
if you turn off mouse raise window, then the problem goes away. But, i want mouse raise window.
sad face.
- SciHub logo Logo Design in Software Industry
good languages now a dime a dozen
it seems, today we've reached a stage where good quality programing language is a dime a dozen.
high availability of quality prog langs don't seem to do much. Programer mindset is very slow to change.
seems we need another 10 years for C C++ java coders to die off. young spur change because they simply not aware what's before.
unicode search, new version
new version. Covering Unicode 8.0.
here: Unicode Search 🔎
the creeping impact of tech, internet
looking at all the video games, such as osu, dancing, all. amazing. You wonder how difficult to write such?
VERY Difficult!
it's a phenomenon where tech is catapulting everything. langs, libs, frameworks, paradigms, all exponential growth, vastly specialized.
in our tech circle, we see self driving car, computer beats human in go , 3D goggle, as demo of tech. actually, impact happen in million places we don't see
these million places, are not reported by the media. The video game osu, is 1 example. you don't know until you run into it.
today, you don't even find philosophers writing about these. but i do. On the Question of Too Many Programing Libs On the Question of Too Many Programing Libraries
you don't find philosophers reporting these phenomenons，not cuz none，but million things are happening that overwhelm'd your ability to be aware of all.
- Douglas Crockford is 61. rob pike is 59. Yukihiro Matsumoto 51. Brendan Eich 54.
- these people more or less still code. don't know about Eich.
- i have been a failure. my life is at the ending. Xah Lee amounted to be a troll, best known as. Oh, and petty emacs tutorial.
- i still consider basically all my rants correct, and the lispers and perlers and python folks i argued with in decades are idiots.
- i'm giving myself about 5 years to do something. after that, the brain is really gone.
- a deep hatred has sustained my life. truly.
- 5 years isn't much. eg learn some math i always wanted to know, algebraic geometry, topology, godel stuff, would take good 2 or 3 years.
- but in 5 years, i could probably still code 1 or 2 project, really well, and say, be known for it.
- there's 2 faces on twitter. 1 marketing, say good things, encouragement. be positive. i've been trying todo, to peddle my website.
- but that's not me. once in a while, i can't help but hurst out the most hateful things. and there goes all my followers, aliented friends.
- the promotional, positive, happy stuff, is rather the most despicable. they spring from profiting. and is the worst of humanity.
linux command 「gksudo」
you can use gksudo to launch X11 apps, such as gksudo nautilus
the purpose is similar to sudo
man gksudo says:
gksu is a frontend to su and gksudo is a frontend to sudo. Their primary purpose is to run graphical commands that need root without the need to run an X terminal emulator and using su directly.
but when you actually need it?
apparently, sometimes when you need to sudo nautilus
and it made the
~/.Xauthority owned by root (should be owned by user).
Then, this create a problem where user can't login when in lightdm.
(lightdm is the login screen.)
reference: http://askubuntu.com/questions/300682/what-represent-xauthority-file
A Spontaneous Rant on D3.js
i think i seriously dislike d3.js. at this point, i think it's hack of hack. looks cool http://bl.ocks.org/mbostock/4063318 but the code, wtf?
there, you'll see it's doing pen drawing commands of svg path element. holy cow, a beautiful widely used powerful library and there it is, manually hacked up pen drawing commands of path of svg.
am this point, am not certain, either i'm totaly old and irrelevant, or d3 is truly shit of the “modern” programing generation fashion.
i mean, i look at the page, its descriptions, and thougt wow, this is well done. How is it possible to draw those calendar with so short code?
and, d3's code has always been incomprehensible. I've tried to study it a couple times since 3 years ago.
it's kinda weird. Its design is kinda weird. It claims that it doesn't lock you into any framework's functions, that d3 simply works with web standards. But actually, if you look at its design, with reactive programing “selection” “enter” “exit”, it right off the bat lock you into d3.
Yeah, d3.js is weird. You know? I've done math visualization for at least 10 years [see Visual Dictionary of Special Plane Curves] , and i know JavaScript the language very well, and i know DOM fairly well. [see JavaScript in Depth] But, it's still hard to understand d3.js. [see Practical SVG Tutorial]
d3's home page https://d3js.org/ is just so impressive, and i have no doubt the lib is quality. After all, the lib has become basically the industrial standard, and the author and his work came from research projects.
but, but, d3 is really weird. How's it weird?
first, the way it does things, is by this certain “selection”, then “enter”.
like, you want to plot a bar chart or pie chart. You look for a function named barChart or drawRectangle, but there is no such. You just got these incomprehensible “enter” and “data” and “transformation” stuff.
there are several things here. This is some kinda reactive programing. That is, functions are bind to data, and when data changes, functions reflects it right off. This is kinda new. But, maybe am old, or not familiar with angular or backbone or facebook react, maybe that's why i find it incomprehensible. Is that it? Many of you work in the industry with these libs. But does any has problem with d3 as i do?
am sorry Mike Bostock, but a man's gotta rant.
but maybe, in a few years i'll think that D3 is really the right way.
On the Question of Too Many Programing Libraries (on a page by itself)
adaptive sampling explained
“look into my eyes, and you'll be reduced to a pawn”