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2017/06/27

Reverse Engineering Google Maps at Highway Speed



I was on I-70 in Maryland on Sunday, going to Alexandria, Virginia, along with a lot of others. I was using Google Maps for navigation. When I could look down, the route was looking red, indicating congestion and delay. Eventually, Google said, "We have an alternate route that will save you a half hour. Want to take it?"

Of course I said yes. So I took the next exit, went down some rural highways, through a small town and almost down someone's driveway, it seemed, and back onto I-70. I called it a win.

The Friday after, on my way home, it rained all the way through Maryland, West Virginia, Pennsylvania and Ohio, and well into Indiana. It occasionally rained hard enough that I started seeing other drivers turning on their hazard lights for others to see them, and I followed suit.

A truck had crashed in western Ohio, closing westbound lanes, and Google told me it would add an hour delay, but when it routed me through five miles of county roads to the next on-ramp, it was closed. I knew it -- I saw the chain across the road -- but Google didn't, so I alone, without a line of other vehicles, bird-dogged a route to the next on-ramp with Google urging me to make a u-turn every few hundred feet.

This made me think about what's actually going on inside the navigation feature of Google Maps. It starts in graph theory, establishing the US road system as a directed graph with weighted edges, showing Interstates as preferable to highways to county roads and side streets, and using Dijykstra's shortest path algorithm to find the best route.

In graph theory, everything is either a node or an edge. In this case, a node could be the intersection of 6th and Main, or the fork where I-70 splits off to I-270.  The edges would be the road between 5th and 6th on Main St., or the long path between exits on the Interstate. In other uses of graph theory, the nodes are most important -- Facebook Users being nodes and their friendships being edges in Facebook's Social Graph -- but here, the information about the edges is the important part.

This is similar to how we used to do it, looking at a paper map and preferring Interstate for long-haul routes, judging this road or that road as preferable due to scenery or a hundred other criteria, dropping to surface streets only to get through the final few miles. But, Google knows this road gets gridlocked at rush hour and that one is under construction, which you can't tell from your ten-year-old road atlas, and has a huge body of historical data that allows it to present alternate routes and the estimated time difference between.

The increasing amount of data helps it properly weigh edges and make connections. Early in my time with Maps, it suggested I go from Lafayette to Ft Wayne through Indianapolis, which would actually add an hour to the trip, because it had weighted the Interstate so highly. Now, it properly suggests two east-west routes and avoids the southern detour entirely. Similarly, an intersection near work is right-turn only, and it took some time for Maps to not suggest a left turn.

Maps re-calculates the route often, which is why, after a time off its path, it still says "fastest way is behind you; turn around and go back". When you're just stopping for gas, it's a little annoying, but when you see that the highway department has blocked the suggested route, you wish it would just shut up and get with the program. I'd have to take more trips where I'm not the driver to really tell, but I would guess it re-runs shortest-path several times a minute. My guess is there are waypoints, places along the route between here and there, so Maps tries to find the shortest path between them, rather than rethinking every turn in your 600-mile journey, which makes this faster and more predictable.

Maps has a lot of data for each section of road, showing how many drivers use it and their average speed, as well as the posted speed limit. If the drivers are going slower than average and slower than the speed limit, that indicates there is a problem. In the Ohio case, the Department of Transportation must have reported that the reason was an accident, but to paraphrase Scream, causes are incidental. What's important is knowing where things get back to normal, and if cars aren't there, then Maps has no way of knowing where that is and what on-ramp is open. This is guesswork of the highest order, but in a week where my every movement was guided by Maps' algorithms, this was the only point of failure.

When I took that detour in Maryland, I was not alone; I counted at least eight vehicles taking that route along with me. Google offered me the choice, but this can't have been an option for every driver on a backed-up highway. I think there must have been a process of A-B testing, where some were rerouted and some were kept on the main road, and it used this information to decide where to send drivers later.

I don't often take these long drives, so it may be a year or two before I'm so fully in the hands of Google Maps and on such a dynamic journey, but I expect the experience to be even better.

2017/06/19

Feeling "Tipsy": The Perl Conference 2017 Day 1

A few lessons learned before I dive into the talks I attended and what I gained from them:

  • I had figured that aspects of my Every Day Carry would not be appreciated in a government building, so I left my multitool off my belt, but, even after I had put everything I could think of into the tray, I had still made the machines go beep, causing the guards to pull out the wand. Tomorrow, pack lighter.
  • I take notes on a paper notebook, but I used my phone and tablet to connect to others via IRC and Twitter, as well as keeping track of my calendar, and I ran through my batteries before the end of the talks. In part, it was switching between the local WiFi and the cellular network, doing well with neither, but I'm not convinced it'd wouldn't be drained regardless. At lunch, I need to find a place to charge. I often come with a power strip for just this purpose, too.
  • I didn't break out the laptop once. If I don't use it more, I should just leave it and have less to carry.
Hopefully, I will remember this and come prepared for the next one.

Now, to the talks:

I started the day with MetaCPAN, the Grand Tour. I had been convinced earlier that MetaCPAN is better than CPAN for looking into modules, but there's more, including modules I am going to have start using to search CPAN.  

Graham Knop's Continuous Integration for CPAN followed. I had been aware of Travis-CI, and had become aware of AppVeyor recently, but the tooling available in Perl to work with these was less familiar to me. I was unaware that you can specify Linux or OSX in Travis, This was something I was thinking and asking questions of other developers about. I have issues on FreeBSD, which I'm told is something that Gitlab-CI can help me with, but somehow, I doubt I can connect Github to Gitlab, but I could be wrong.

Steven Lembark had much more with Dockerizing CPAN Testers: Running an Isolated Test Site than I could fit into my head, and I think I'll have to go back to the tape once it's available, but I think it's a useful addition to the world.

After lunch, I went to Joel Berger's Variables, Scoping and Namespaces, which he set as a talk for beginners. He went so far as to suggest more established developers go elsewhere. Since I never thought I learned all of Perl when I was learning, it was very much a lot of things I did already know, but a little "So that's why we do that", some more "Oooh. I forgot about that", and one weird trick that explains how to mock functions for tests.

(That, fundamentally, is my big item to work on as a developer. Testing.)

After this, I attended Matt S. Trout's ES6: Almost an acceptable Perl 5? and it gave me a sense of treating Javascript like Perl, but since I don't code Perl like Matt does, I probably won't code ES6 like Matt does. My notes peter out about halfway through, but they do include several gems, such as lodash, that might improve the code I do write.

Following this is Lightning Talks, which has a bunch of interesting points, going from "Write for OpenSource.com" to "Try learning Dart" to "Creating Test JSON from JSON Schemas" to "Using Instapaper, IFTTT and Buffer to tweet what you read" to the Alien modules, which I almost understand now. Or maybe not. Certainly, though, I'd be installing and trying Dave Rolsky's RTx-toGitHub right now if I wasn't so tired.

Finally, Sawyer X talked about Perl 5.26 and the changes that came and the changes that are coming. The thing that comes to mind first is that things that have been deprecated since 5.0 are finally being pulled. I understand the critics who think that removing . from @INC is insignificant, but I am still for it. I also like that Perl recognizes unhandled merges and dies now. 

Tomorrow, I will be learning about Dancer, Test2 and more with @INC, and visiting with family after

2017/06/02

Tracking your Old Tabs in Chrome over Time

Starting "Has this ever happened to you?" is a very informercial way to start, but it's where my brain has left me: Working on your computer and suddenly, something happens. Blue screen. Kernel panic. Browser crash. Whatever. Restart things, open Chrome and click "Restore Tabs" and it ... does nothing.

Or does something, but not enough.

A user's list of open browser tabs and windows is a map of that user's interests. For me, there's usually 6-20 open windows with 3-12 tabs covering a number of topics that, while interesting to you, are not directly applicable right now.

And Chrome is of no help these days. As Neil Young said "It's all the same song", Google believes, between phones, tablets, laptops, desktops — heck, the talking-donkey called Google Home, for all I know — that it's all the same browser. Pages you saw recently, no matter what device, are at the top of chrome://history, and the tabs that you kept around for when you get back to that topic are way dropped out, and ironically, the tabs you looked at, rejected and closed are right at the top.

Last night, I killed lots of tabs to enhance browser stability. Today, looking for an image, I screwed up my machine, and so I rebooted. It's Linux and that's bad Linux admin work, but it wasn't a hill I wanted to die on, and when I got back on, the six windows and maybe 20 tabs total were gone. There were certain givens (Tweetdeck, Chrome) and certain trashables (work tabs for tasks completed the day before) but the "I was gonna get back to that" windows are gone, and the pages they held are deep deep deep in the communal history behind today's web comics and headline links.


I cannot get those pages and the plans I built on them back. But, I can start to get my house in order to keep it from happening again. And that starts with storing them.

This page shows the default location for Chrome user data. Lifehacker has a how-to on Restoring tabs, detailing what files hold what you need and how to force Chrome into Recovery Mode. the key things are in Current Session, Current Tabs, Last Session and Last Tabs. These files are SNSS format, which could be better (I've found a Github repo with an SNSS parser in Python, but haven't started working with it), but they respond to strings, so you have something to work on without the parser.

#!/usr/bin/env perl

use feature qw{ say state } ;
use strict ;
use warnings ;
use utf8 ;

use DateTime ;
use File::Copy ;
use File::Path qw{ make_path } ;
use IO::Interactive qw{ interactive } ;

# program to back up chrome tabs for easy restore should things go bad
# add to your crontab with something like
#       @hourly ~/bin/chrome_tab_backup.pl

# T
#

my $now = DateTime->now()
                  ->set_time_zone('America/Indiana/Indianapolis')
                  ->set( second => 0 ) ;

my $date = $now->ymd('/') ;
my $time = $now->hms('-') ;

my $source = join '/', $ENV{HOME}, qw{ .config chromium Default } ;
my $target = join '/', $ENV{HOME}, '.chrome_backup', $date, $time ;
say $source ;
say $target ;

if ( !-d $target ) {
    my @dirs = make_path($target) ;
    }

chdir $source ;
for my $f ( grep {m{(Tabs|Session)$}n} glob '*' ) {
    say $f ;
    copy( $f, $target ) or die qq{Copy Failed: $! } ;
    }

There's a bit of generalization in this. I would prefer to make it discern what TZ you're in without hard-coding it, and I could just use UTC and everyone would know to look for the most recent one.

The Lifehacker page points to a Windows-specific (or maybe Windows and Mac, I dunno) Local State file as where you set exited_cleanly to false in order to force recovery, while in Linux it's Preferences.

Where this leaves us is a bunch of files in the directory. I could figure out a way to parse the SNSS. I could create an HTML page showing that time's open tabs, which obviates the need to force Chrome to open the correct tabs. I could begin to start grouping them by window and time, saying "You've been wanting to get back to MQTT for some time; fish or cut bait".

Plus, this example is very Linux-centric, meant to service Chromium and run in crontab. Making it run on Win7 or Win10 and Strawberry Perl and be run in Task Manager is important, as really, my Windows machine is for browsing and testing.

If all I get is "Hey, give me my tabs back!", I'll be happy.

2017/05/22

Testing Perl Modules on Windows: A Cry For Help

I've been working on modules again, after a recent push, and I found a big project whose .travis.yml file only went to Perl 5.20. I thought I'd get some dev brownie points by adding the next two stable versions, and found that my build was dying in the Pull Request submission process.

Specifically, it was dying on the checks. It passes Travis-CI, which runs the tests on Unix-like systems, but it was failing with Appveyor.

"What is Appveyor?", I asked myself.

Perhaps this isn't a direct quote.

Appveyor is a continuous integration service that tests against Windows systems. Scott Hanselman wrote a glowing review of it three years ago.

But there's no .appveyor.yml file in the project, so it runs and fails.

I've mentioned this on the project IRC, and no, I'm not going to name names, because there is movement toward testing on Windows, and even if it doesn't work, I admire the goal.

I wrote this three years ago, in response to a Python conference video:
2) Sure, real programmers use Unix/Linux to run their code, real programmers, but beginner programmers don't come in knowing how to set up an environment and come in with the (Windows) computer they have, and the documentation sucks and they feel lost and they don't like it and they don't feel the power, and they're gone. Even if you dislike Microsoft, good tools for Windows and good documentation are important for new programmers, important for building community, important for inclusiveness.
I run Windows, but I program on and for Linux, and only have one project based on Windows. But I have installed ActiveState and Strawberry Perls, and think that if you write general-purpose modules, you should be sure to test against Windows as well as Linux.

But, Travis-CI has documentation covering Perl projects. Appveyor says you can use Perl 5.20. eserte wrote a post on Appveyor for blogs.perl.org last year, but I'd love to see better documentation from either them, the Perl community or both. Following is the YAML from eserte, with a switch to "check only master branch", but as with Travis, which uses perlbrew and allows testing as far back as 5.8.8, I think having it test against older versions of Perl, both ActivePerl and Strawberry, would be the thing.

branches:
  only:
    - master

skip_tags: true

cache:
  - C:\strawberry



install:

  - if not exist "C:\strawberry" cinst strawberryperl

  - set PATH=C:\strawberry\perl\bin;C:\strawberry\perl\site\bin;C:\strawberry\c\bin;%PATH%

  - cd C:\projects\%APPVEYOR_PROJECT_NAME%

  - cpanm --installdeps .



build_script:

  - perl Makefile.PL

  - dmake test


If you have a more fully-featured .appveyor.yml file you'd like the Perl community to use, especially distinguishing MakeMaker modules from Dist::Zilla modules, I'd love to see it.

2017/05/17

Contact Me! (If you REALLY need to)

A recent comment from Schlomi Fish said:
Hi! I cannot seem to find any contact information on this page. How should I contact you?
And then linked to a FAQ entry explaining his position on the state of email, comparing the futility of hiding addresses and the benefits of being open.

I have to say, I hadn't thought about this in ... years? In general, I'm active on Twitter (@jacobydave), which is good if you are, but not helpful if you aren't. I try to keep track of the comments, but that doesn't fit every message a person would want to send me.

So, a friendly "Hey, you should put your email on your blog" comment makes sense to me.

But, adding more traffic to the mailbox that friends and relatives have access to doesn't. I'm happy to put up an email address, but I'm less than happy to make it my main email address. It goes to context; my coworkers generally don't get that one either.

I had a long, barely touched by me but used enough by others project that was R syntax highlighting in Komodo Edit, which is dead because it's now native, but the ActiveState packaging used an email address to set the id, so, I created rlangsyntax@gmail.com.

So, to the right, in a section called "More Of Me", there is a requested mailto: pointing to rlangsyntax@gmail.com. I will check it. Use it in good health.

2017/05/08

Coffee and Code and Calendars and R

I have what you might call a conflicted relationship with caffeine.



Long story short: I found it necessary to cut down on caffeine, limiting myself to two cups a day, preferrably before noon, and, as sort of a measure of accountability, and as a way to gain more skill with SQL and R, I wrote tools that store when I drink coffee and, at the end of the work day, tweeting the image.


I forget exactly where I found the calendar heatmap code, but it was several years ago, and was one of the first instances of ggplot2 that I found and put into service. I chose a brown-to-black color scheme because, well, obviously it needed to look like coffee.

This image, with "Dave has had n cups of coffee today" is autotweeted every day at 6pm Eastern. Recently, it has drawn interest.


So here it is, both blogged and gisted.


I started doing that thing with YAML in Perl, to keep database keys out of programs. I'm reasonably okay with my SQL skills, I think, but I am clear that my R code is largely cargo-cult. It'd be good to replace 2,4,6 with the days of the week,  and I am reasonably sure that it's reversed from the way you'd normally expect weekdays to go. Some day, I'll have the knowledge required to make those changes.

If you have questions and comments about this, I'd be glad to take them on, but I'm very much the learner when it comes to R.

count is not uniq...

I recall reading something online about 20 years ago (gasp!) where the authors were looking for a core set of knowledge that would constitute "knowing Unix", and found that there just wasn't. Knowing Unix was like the Humpty Dance, in that no two people do it the same.

And, presumably, you have Unix down when you appear to be in pain.


I have been a Unix/Linux user since the 1990s and I only found out about uniq -c because of the last post. I had been using sort | uniq forever, and have recently stopped in favor of sort -u, which I also learned about recently.

I find that uniq is kinda useless without a sort in front of it; if your input is "foo foo foo bar foo" (with requisite newlines, of course), uniq without sort will give you "foo bar foo" instead of "foo bar" or "bar foo", either of which is closer to what I want.

So, I could see adding alias count=" sort | uniq " to my bash setup, but adding a count program to my ~/bin seems much better to me, much closer to the Right Thing.

marc chantreux suggested an implementation of count that is perhaps better and certainly shorter than the one I posted. There was regex magic that I simply didn't need, because I wanted the count to stand by itself (but I might revisit to remove the awk step, because as a user, I'm still a bit awkward with it.)

B)

my %seen ;

map { $seen{$_}++ } do {
    @ARGV ? @ARGV : map { chomp ; $_ } <>;
    } ;

while ( my ( $k, $v ) = each %seen ) {
    say join "\t", $v, $k ;
    }
I like marc's use of the ternary operator to handle STDIN vs @ARGV, but I'm somewhat inconsistently against map over for. I know people who thing that map not going into an array is a problem, so I don't go back to it often.

I do, however, do for my $k ( keys %seen ) { ... } enough that I'm sort of mad at myself for not encountering each before.

ETA: It's been brought to my attention that using map {} as a replacement for for () {} is not good.


2017/05/05

One! One New Utility! Bwa-ha-hahaha!

Classic unix utilities give you a number of great tools, and you can use sed and awk and bash when those aren't enough.

But sometimes ...

I use ~ as a scratch space all too often, which leaves me with a huge amount of files that I stopped playing with a while ago. I can get to the point of knowing what types, sure, as I show here.

$ ls *.* | awk -F. '{ print $NF }' 
jpg
jpg
jpg
jpg
txt
txt
txt
pl
txt
txt
pl
txt
pl
pl
txt
html
pl
pl
gz
mp3
pl
pl
pl
pl
txt
pl
pl
sh
sh
txt
pl
pl
diff
txt
txt
txt
pl
txt
pl
txt
txt
txt
txt
py
...

But this only gets you so far. I can sort and know that there's a LOT of Perl files, perhaps too many, but nothing was immediate about telling me how many.

But hey, I am a programmer, so I wrote a solution.

And here it is in a shell, combined with sort in order to give me the numbers, which includes a lot of throwaway Perl programs.

$ ls *.* | awk -F. '{ print $NF }' | count | sort -nr

95 pl
59 txt
10 sh
10 jpg
8 py
6 html
6 csv
5 js
2 gz
2 diff
1 zip
1 ttf
1 tt
1 svg
1 sql
1 Rd
1 R
1 pub
1 png
1 pdf
1 mp4
1 mp3
1 log
1 json
1 foo
1 conf
1 cnf


I suppose I need to do some cleanup in $HOME today...

2017/03/14

Coding for Pi Day

Today is Pi Day, which is a good day to talk about Pi.

Normally, I'd probably use Pi, sine and cosine to draw things, but instead, I flashed on a couple ways to estimate Pi.

Also, showing you can use Unicode characters in Perl.

#!/usr/bin/env perl

use feature qw{ say } ;
use strict ;
use warnings ;
use utf8 ;

my $π = 3.14159 ;

my $est2  = estimate_2() ;
my $diff2 = sprintf '%.5f',abs $π - $est2 ;
say qq{Estimate 2: $est2 - off by $diff2} ;

my $est1  = estimate_1() ;
my $diff1 = sprintf '%.5f',abs $π - $est1 ;
say qq{Estimate 1: $est1 - off by $diff1} ;

exit ;

# concept here is that the area of a circle = π * rsquared
# if r == 1, area = π. If we just take the part of the circle
# where x and y are positive, that'll be π/4. So, take a random
# point between 0,0 and 1,1 see if the distance between it and 
# 0,0 is < 1. If so, we increment, and the count / the number
# so far is an estimate of π.

# because randomness, this will change each time you run it

sub estimate_1 {
    srand ;
    my $inside = 0.0 ;
    my $pi ;
    for my $i ( 1 .. 1_000_000 ) {
        my $x = rand ;
        my $y = rand ;
        $inside++ if $x * $x + $y * $y < 1.0 ;
        $pi = sprintf '%.5f', 4 * $inside / $i ;
        }
    return $pi ;
    }

# concept here is that π can be estimated by 4 ( 1 - 1/3 + 1/5 - 1/7 ...)
# so we get closer the further we go
sub estimate_2 {
    my $pi = 0;
    my $c  = 0;
    for my $i ( 0 .. 1_000_000 ) {
        my $j = 2 * $i + 1 ;
        if ( $i % 2 == 1 ) { $c -= 1 / $j ; }
        else               { $c += 1 / $j ; }
        $pi = sprintf '%.5f', 4 * $c ;
        }
    return $pi ;
    }

2017/02/28

Having Problems Munging Data in R

#!/group/bioinfo/apps/apps/R-3.1.2/bin/Rscript

# a blog post in code-and-comment form

# Between having some problems with our VMs and wanting 
# to learn Log::Log4perl. I wrote a program that took 
# the load average -- at first at the hour, via 
# crontab -- and stored the value. And, if the load 
# average was > 20, it would send me an alert

# It used to be a problem. It is no longer. Now I 
# just want to learn how to munge data in R

# read in file
logfile = read.table('~/.uptime.log')

# The logfile looks like this:
#
#   2017/01/01 00:02:01 genomics-test : 0.36 0.09 0.03
#   2017/01/01 00:02:02 genomics : 0.04 0.03 0.04
#   2017/01/01 00:02:02 genomics-db : 0.12 0.05 0.01
#   2017/01/01 00:02:04 genomics-apps : 1.87 1.24 0.79
#   2017/01/01 01:02:02 genomics-db : 0.24 0.14 0.05
#   2017/01/01 01:02:02 genomics-test : 0.53 0.14 0.04
#   2017/01/01 01:02:03 genomics : 0.13 0.09 0.08
#   2017/01/01 01:02:04 genomics-apps : 1.66 1.82 1.58
#   2017/01/01 02:02:01 genomics-test : 0.15 0.03 0.01
#   ...

# set column names
colnames(logfile)=c('date','time','host','colon','load','x','y')

# now:
#
#   date       time     host         colon load x y
#   2017/01/01 00:02:01 genomics-test : 0.36 0.09 0.03
#   2017/01/01 00:02:02 genomics : 0.04 0.03 0.04

logfile$datetime <- paste( as.character(logfile$date) , as.character(logfile$time) )
# datetime == 'YYYY/MM/DD HH:MM:SS'
logfile$datetime <- sub('......$','',logfile$datetime)
# datetime == 'YYYY/MM/DD HH'
logfile$datetime <- sub('/','',logfile$datetime)
# datetime == 'YYYYMM/DD HH'
logfile$datetime <- sub('/','',logfile$datetime)
# datetime == 'YYYYMMDD HH'
logfile$datetime <- sub(' ','',logfile$datetime)
# datetime == 'YYYYMMDDHH'

# for every datetime in logfile. I love clean data

# removes several columns we no longer need

logfile$time    <- NULL
logfile$date    <- NULL
logfile$colon   <- NULL
logfile$x       <- NULL
logfile$y       <- NULL

# logfile now looks like this:
#
#   datetime  host             load
#   2017010100 genomics-test    0.36 
#   2017010100 genomics         0.04 
#   2017010100 genomics-db      0.12 
#   2017010100 genomics-apps    1.87 
#   2017010101 genomics-db      0.24 
#   2017010101 genomics-test    0.53 
#   2017010101 genomics         0.13 
#   2017010101 genomics-apps    1.66 
#   2017010102 genomics-test    0.15 
#   ...

# and we can get the X and Y for a big huge replacement table
hosts <- unique(logfile$host[order(logfile$host)])
dates <- unique(logfile$datetime)

# because what we want is something closer to this
#
#   datetime        genomics    genomics-apps   genomics-db     genomics-test
#   2017010100      0.04        1.87            0.12            0.36
#   2017010101      0.13        1.66            0.15            0.53
#   ...

# let's try to put it into a dataframe

uptime.data <- data.frame()
uptime.data$datetime <- vector() ;
for ( h in hosts ) {
    uptime.data[h] <- vector()
    } 

# and here, we have a data frame that looks like 
#
#   datetime        genomics    genomics-apps   genomics-db     genomics-test
#
# as I understand it, you can only append to a data frame by merging.
# I need to create a data frame that looks like
#
#   datetime        genomics    genomics-apps   genomics-db     genomics-test
#   2017010100      0.04        1.87            0.12            0.36
#
# and then merge that. Then do the same with 
#
#   datetime        genomics    genomics-apps   genomics-db     genomics-test
#   2017010101      0.13        1.66            0.15            0.53
#
# and so on.
#
# I don't know how to do that. 
#
# I *think* the way is make a one-vector data frame:
#
#   datetime        
#   2017010101      
#
# and add the vectors one at a time.

for ( d in dates ) {

    # we don't and the whole log here. we just want 
    # this hour's data
    # 
    #   datetime  host             load
    #   2017010100 genomics-test    0.36 
    #   2017010100 genomics         0.04 
    #   2017010100 genomics-db      0.12 
    #   2017010100 genomics-apps    1.87 
    log <- subset(logfile, datetime==d)

    print(d)

    for ( h in hosts ) {
        # and we can narrow it down further
        # 
        #   datetime  host             load
        #   2017010100 genomics         0.04 
        hostv <- subset(log,host==h)
        load = hostv$load 
        # problem is, due to fun LDAP issues, sometimes 
        # the logging doesn't happen
        if ( 0 == length(load) ) { load <- -1 }
        print(paste(h, load ))
    }

    # and here's where I'm hung. I can get all the pieces 
    # I want, even -1 for missing values, but I can't seem  
    # to put it together into a one-row data frame
    # to append to uptime.data. 

    #   [1] "2017010100"
    #   [1] "genomics 0.04"
    #   [1] "genomics-apps 1.87"
    #   [1] "genomics-db 0.12"
    #   [1] "genomics-test 0.36"
    #   [1] "2017010101"
    #   [1] "genomics 0.13"
    #   [1] "genomics-apps 1.66"
    #   [1] "genomics-db 0.24"
    #   [1] "genomics-test 0.53"
    #   [1] "2017010102"
    #   [1] "genomics 0.36"
    #   [1] "genomics-apps 0.71"
    #   [1] "genomics-db 0.08"
    #   [1] "genomics-test 0.15"

}

2017/01/20

Ding! Ding! The Process is Dead!

Starts with a thing I saw on David Walsh's Blog:
I've been working with beefy virtual machines, docker containers, and build processes lately. Believe it or not, working on projects aimed at making Mozilla developers more productive can mean executing code that can take anywhere from a minute to an hour, which in itself can hit how productive I can be. For the longer tasks, I often get away from my desk, make a cup of coffee, and check in to see how the rest of the Walsh clan is doing.

When I walk away, however, it would be nice to know when the task is done, so I can jet back to my desk and get back to work. My awesome Mozilla colleague Byron "glob" Jones recently showed me his script for task completion notification and I forced him to put it up on GitHub so you all can get it too; it's called ding!
OK, that sounds cool. So I go to Github and I see one line that gives me pause.

Requires ding.mp3 and error.mp3 in same directory as script. OSX only.

I can handle the image thing, but I don't own or run an OSX computer. (I have one somewhere, but it's ancient and has no functioning battery. I don't use it.)

"So," I think, "how could I do this on my Linux box? What's the shortest path toward functionality on this concept?"

Well, recently, I have been playing with Text-to-Speech. Actually, I have been a long-time user of TTS, using festival then espeak to tell me the current time and temperature on the hour and half-hour. I switched to Amazon's Polly in December, deciding that the service sounded much better than the on-my-computer choices. (Hear for yourself.) So, I knew how to handle the audio aspects.

The other part required me to get much more familiar with Perl's system function than I had been previously.


I'm not yet 100% happy with this code, but I'm reasonably okay with it so far. Certainly the concept has been proven. (I use the audio files from globau's ding.) With enough interest, I will switch it from being a GitHub gist to being a repo.