Where : Shopigniter's Office 

When : Tuesday, May 15th, 6:30pm - 8pm'ish Pizza and beverage provided by Shopigniter. 

Topic(s): Open for topic suggestions

simply comment here or on the mailing list to propose topics you would like to present

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Just some of my random thoughts on startups.

If you find yourself in a startups were your sole and/or primary metric of success is "market share" and you see your market share increasing, don't fall under the assumption that you are succeeding as a startup. Remember, you started at 0%, so an increase is not too difficult to pull off.

The bigger issue of focusing on market share is that you are tricking yourself into believing that startups are not as risky as they actually are. You must take risks and truly innovate for them to succeed.

Your best case with this market share focus is an eventual plateau of success (curve B) far below what you could achieve with the alternative tactic.

That alternative tactic being:  focus primarily on true innovation.  Do something that is not being currently done or do something in a completely different way.  Don't aim for what can be done in the current reality, but instead what can be done in the soon to be reality.  Also start out (and remain) passionate and completely focused your product.

In this case you have a chance of hitting curve D. (that market share amassed naturally).  Yes, the odds are, you will hit curve C but in that case you will hit it quickly and can course correct with a substantial pivot of the project or abandon and move onto the next, entirely different project.  In contrast, with the probable outcome of the market share driven startup, it takes much longer for curve A to drop, meaning, your business will be on the failing track for longer before you detect that a course correction is needed.  At that point, it is probably too late.

Of course "Success" in the graphs below is abstract and entirely open to interpretation, but discussing that would be a whole new post.

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Arrays in PHP are quite powerful, partly because they are not actually arrays (read on for an explanation), but can be treated as such when needed. They gain most of the utility from a vast library of built in helper functions associated with them.

Much of my day is spent looking at others code, (were ‘others’ does include ‘me in the past’), and I often see arrays under utilized or code that fights arrays by implementing foreach loops where a single function call would suffice. With some review of the functionality afforded arrays in PHP you can learn to use them more effectively and realize that they may very well be the best solution in circumstances you had not thought of before. This is nothing against Object Oriented Programming, as I consider myself a OO programmer. There is just quite a bit that can be done efficiently and elegantly with plain old arrays in PHP.

So as a refresher course for myself and hopefully to show others some array functionality they were not aware existed, I’ve decided to write a few blog posts on some things I find useful (and have newly discovered after re-reading the array docs).

This being the first of those posts, I’ll start with the basics, a very quick intro to just what an array is and then cover examples of using arrays as some of the more simple data structures in computer science: Stacks and Queues.

What Is An Array In PHP?

What is referred to as an ‘array’ in PHP is actually an ordered map. The keys of an array can be either an integer or a string. The value for an array element can be anything.

Arrays can be created using the array() construct or in a more literal fashion of using brackets ([ ])

$x = array('bob');
$x = array(0 => 'bob');
$x[] = 'bob';
$x[0] = 'bob';

All the examples above will result in this array:

array(0 => 'bob')

If a key is not specified for a value, a new key is created with the value of 1 + the current max of the integer keys in the array.

$y = array(0 => 'red', 1 => 'blue', 7 => 'green');
$y[] = 'brown';

The $y array would now be:

$y = array(0 => 'red', 1 => 'blue', 7 => 'green', 8 => 'brown');

For more of the basics of PHP arrays, there is an excellent php.net page devoted to that subject.

Using Arrays For Basic Data Structures

Stacks

In computer science, a Stack is a last in, first out (LIFO) structure.

>push     pop>
     \   /
       X
       X
       X
       X
       X

An example of a Stack is your browser history. You click a link and it is pushed onto the top of your browser history. You continue to click links and they are continually pushed onto the top of that Stack. Then when you click on the ‘back’ button, the very top link is popped of your history Stack.

In PHP the functions array_push and array_pop are used for manipulating an array as a Stack.

$browser_history = array('https://mail.google.com', 'http://www.php.net' );
array_push($browser_history, 'http://www.topgear.com/uk/');


print_r($browser_history);

// Array
// (
//     [0] => https://mail.google.com
//     [1] => http://www.php.net
//     [2] => http://www.topgear.com/uk/
// )

$site = array_pop($browser_history);
echo "site: {$site}";

// site: http://www.topgear.com/uk/

print_r($browser_history);

// Array
// (
//     [0] => https://mail.google.com
//     [1] => http://www.php.net
// )

Note that in PHP, rather than using array_push, you can just use bracketed syntax which has the same effect.

array_push($array, 'value')
// has the same effect as
$array[] = 'value';

Queues

A Queue is a First-In-First-Out (FIFO) data structure. (think conveyor belt)

enqueue                  dequeue
(unshift)      queue      (shift)
       X -->  XXXXXXX -->  X

In PHP, you can use an array as a Queue by utilizing array_unshift to prepend and element to the beginning of an array and then array_pop to take an element off the end of the same array.

An example would be any perishable items in your grocery store’s dairy case. As items come into the store they are loaded in the back of the case and customers select items for purchase from the front of the case.

$yogurts = array('exp:05/10/2011', 'exp:05/08/2011' );

print_r($yogurts);

//Array
//(
//  [0] => exp:05/10/2011
//  [1] => exp:05/08/2011
//)

array_unshift($yogurts, 'exp:05/13/2011', 'exp:05/12/2011');

print_r($yogurts);

//Array
//(
//  [0] => exp:05/13/2011
//  [1] => exp:05/12/2011
//  [2] => exp:05/10/2011
//  [3] => exp:05/08/2011
//)

Note, these methods do not return the affected array so you wouldn’t normally do:

$yogurts = array_unshift($yogurts, 'exp:05/13/2011', 'exp:05/12/2011');

as array_pop simply returns the last value of the array and array_unshift returns the new number of elements in the array.

So that is it for now, next up I’ll discuss using the various function to calculate the differences and intersections between array.

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After much trial and error, this is what worked for me on a macbook pro, running snow leopard 10.6.6.

$ brew install python
$ sudo easy_install pip
$ pip install virtualenv
$ pip install virtualenvwrapper 
$ vi ~/.profile
   # add this line to .profile
   source /usr/local/Cellar/python/2.7.1/bin/virtualenvwrapper.sh

$ source ~/.profile

First install a current Python (OSX python is outdated).

Then use easy_install to install its replacement: pip. (use pip after this)

Then use pip to install virtualenv and virtualenvwrapper (python's env manager.  Think Ruby rvm)

The docs for virtualenvwrapper are at http://www.doughellmann.com/docs/virtualenvwrapper/

Example of creating python env

$ mkvirtualenv env-0
New python executable in env-0/bin/python
Installing setuptools............................done.
virtualenvwrapper.user_scripts creating /Users/sam/.virtualenvs/env-0/bin/predeactivate
virtualenvwrapper.user_scripts creating /Users/sam/.virtualenvs/env-0/bin/postdeactivate
virtualenvwrapper.user_scripts creating /Users/sam/.virtualenvs/env-0/bin/preactivate
virtualenvwrapper.user_scripts creating /Users/sam/.virtualenvs/env-0/bin/postactivate
virtualenvwrapper.user_scripts creating /Users/sam/.virtualenvs/env-0/bin/get_env_details

$ ll $WORKON_HOME
total 88
drwxr-xr-x  5 sam  staff   170 Mar 25 08:22 env-0
-rwxrwxr-x  1 sam  staff   106 Mar 25 08:18 get_env_details
-rw-r--r--  1 sam  staff  4082 Mar 25 08:33 hook.log
-rwxrwxr-x  1 sam  staff    92 Mar 25 08:18 initialize
-rwxrwxr-x  1 sam  staff    69 Mar 25 08:18 postactivate
-rwxrwxr-x  1 sam  staff    71 Mar 25 08:18 postdeactivate
-rwxrwxr-x  1 sam  staff    69 Mar 25 08:18 postmkvirtualenv
-rwxrwxr-x  1 sam  staff    63 Mar 25 08:18 postrmvirtualenv
-rwxrwxr-x  1 sam  staff    70 Mar 25 08:18 preactivate
-rwxrwxr-x  1 sam  staff    72 Mar 25 08:18 predeactivate
-rwxrwxr-x  1 sam  staff    94 Mar 25 08:18 premkvirtualenv
-rwxrwxr-x  1 sam  staff    64 Mar 25 08:18 prermvirtualenv

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For a development machine, it is sometimes nice to log all mysql queries.

with Mysql, you turn on logging by placing this entry in your my.cnf

[mysqld]
log = /var/log/mysql/mysql.log

In doing that though, the log file can get quite large pretty quickly. I started googleing around for a solution, and found this link to be quite helpful though it didn’t mention mysql logs specifically.

On Leopard, the file that controls log rotation is /etc/newsyslog.conf

The entry I use looks like this.

# logfilename             [owner:group]  mode count  size  when   flags   [/pid_file]                            [sig_num]
/var/log/mysql/mysql.log   mysql:wheel    644  10    1000  *      JS      /usr/local/mysql/data/si-sam.local.pid 30

This rotates mysql.log anytime it grows beyond 1000k and keeps 10 compressed archives on hand

For your machine the actual logfile location can differ and the location and name of the pid file will most certainly be different.

To track down the name and location of your mysql pid file, execute

$ps aux | grep mysqld

and look for the —pid-file=

--pid-file=/usr/local/mysql/data/si-sam.local.pid

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I wrote a small library to wrap the PHP Curl extension in a way that makes the code using it more read-able and keeps you from having to remember all those curl_setopt(…. constants.

Presta on github

Example Use in PHPUnit

With methods in your base test class (what you specific test classes are extending) such as these

/**
  *
  * @param string $uri_path
  * @return Response
  */
  protected function api_get($uri_path)
  {
      return $this->presta
        ->uri($this->build_uri($uri_path))
        ->auth($this->username, $this->password)
        ->get();
  }

  ...

/**
  *
  * @param string $uri_path
  * @return Response
  */
  protected function api_delete($uri_path)
  {
      return $this->presta
        ->uri($this->build_uri($uri_path))
        ->auth($this->username, $this->password)
        ->delete();
  }

Then in a test for deleting through the API, you can have something like this

$response = $this->api_delete("/users/1");
$this->assertTrue($response->status_code==204);
$this->assertEmpty($response->entity_body);
$response = $this->api_get("/users/1");
$this->assertTrue($response->status_code==404);

Plan is to continue refining the code for presta, in addition to writing a 5.3+ version.

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If you ever have PHP print_r output that you just want to cut/paste as PHP code.

class Arr {
  /**
   * $array Can be either an Array or the string output of
   *   print_r($array, true);
   */
  public static function print_php($array) {
    $array = is_array($array)?print_r($array,true):$array;
    $array = preg_replace(
        array(
          '/Array\n/',
          '/\[(.*)\] =>/',
          '/\)\n/'
        ),
        array(
          "array\n",
          '"${1}" =>',
          "),\n"
        ),
      $array);
    // need regex skill++ , for now this will do
    $array = preg_replace_callback(
        '/=> (.*?)\n/',
        // only replace if it is not the word 'array' or just digits
        create_function(
          '$matches',
          '$match = isset($matches[1])?$matches[1]:null;
          $qt = ctype_digit($match)||$match=="array"?"":"\"";
          $c = $match=="array"?"":",";
          return "=> {$qt}{$match}{$qt}{$c}\n";'
        ),
      $array);
    return $array;
  }

}

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ASCII Infographics

Client                     REST
Convenience - <---------- Resource ----------> + Cache-ability,
                         Granularity             Chattiness

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$ curl http://gist.github.com/raw/323731/HEAD/install_homebrew.rb -o /tmp/install_homebrew.rb

$ sudo chown -R $USER /usr/local

$ ruby /tmp/install_homebrew.rb

export PATH="/usr/local/bin:$PATH"

$ brew install python

$ brew install setuptools

$ tar xfz MySQL-python-1.2.1.tar.gz
 $ cd MySQL-python-1.2.1
 $ # edit site.cfg if necessary
 $ python setup.py build
 $ sudo python setup.py install # or su first

$ cd

$ python
Python 2.6.5 (r265:79063, Apr 27 2010, 12:36:14)
[GCC 4.2.1 (Apple Inc. build 5646) (dot 1)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import MySQLdb
>>>

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Quite a while back I grabbed the twitter handle @pdxweather with plans to broadcast the local weather over it. I first thought I would send out a daily broadcast for today's weather and tomorrow.  Being Portland, Oregon, I'm centering around the "Chance of Rain" for those days at least as a starting point. This has proven to be quite a challenge to accomplish with 140 characters. The technology needed to produce such tweets is not all that difficult.  I built a little PHP script that would parse the forecasts from form the weather.gov API.  I then have a PHP script that builds a short summary of that information and tweets it (once a day at this point). http://twitter.com/pdxweather

Attempt 1:

Sun_18th:light rain precip%day:13 precip%eve:29 Mon_19th:light rain precip%day:53 precip%eve:64 (NOAA splits the % chance of rain to day and eve.  I like this feature so I want to have that in the tweets also even though it makes it that much more difficult to stay under 140.) Lots of room for improvement here.

• Hard to see the dividing line between the days
• Not even showing hi/low temps yet and we are at ~95 char so longer weather descriptions (i.e. "Light rain and high wind warning"") along with temps could easily put us over 140
• Overall, it's just hard to parse out the individual bits of information

Attempt 2:

Goals:

• Reduce the overall character count of what we have so far so we can add more info.
• Make the tweet more 'human brain parse-able'

I first trimmed the day descriptions to gain some more characters.

Sun18:light rain precip%day:13 precip%eve:29 Mon19:light rain precip%day:53 precip%eve:64

I then determined correct spelling was optional and substituted lite for light (lite seemed a better solution than lght or lt)

Sun18:lite rain precip%day:13 precip%eve:29 Mon19:lite rain precip%day:53 precip%eve:64

These helped on the character count, but you could easily argue that these make the tweet slightly less readable.  What we really need is something that shortens the character count and at the same time increases its readability.  For this I turned to Unicode.  If I could find a single character to replace a word like 'Sunny' or 'Rain', I could regain many characters to use elsewhere in the Tweet.  I did find some 'weather' glyphs in a miscellaneous section of Unicode, unfortunately most seem to render into illegible blobs because of the typical small size you see them at. I did find

• sun:☼
• snow:✽

but nothing good for rain that was legible at small sizes (does this look like rain on an umbrella?  ☔). 

So I started scanning the Unicode field for something that 'looked' like rain and settled on ⑊. So using ⑊ for rain, we are at:

Sun18:lite ⑊ precip%day:13 precip%eve:29 Mon19:lite ⑊ precip%day:53 precip%eve:64

I then did a major refactor to the order of things and dropped some 'not completely necessary' terms:

Sun18:lite ⑊ 13%day 29%eve Mon19:lite ⑊ 53%day 64%eve

At this point, a great deal of ground has been made on character count, down to 53 characters, or about a 45% reduction. As a final step, I rely on alpha/digit/symbol boundaries and remove space between them.  In an effort to emphasize boundaries, it is back to Unicode with  → and ▮. So here it is at 49 chars:

Sun18 lite⑊13%day→29%eve▮Mon19 lite⑊53%day→64%eve

Original at 95

Sun_18th:light rain precip%day:13 precip%eve:29 Mon_19th:light rain precip%day:53 precip%eve:64

Now What

The goal now it to allow this logic to all weather tweets with will involve building a NOAA weather speak to Tweet Weather speak translator.  So the overall architecture will be

• nightly, hit the NOAA API and and parse/cache the forecast on the local server
• once a day (or more), use that cached data to tweet the forcast

So I'm off to finish that,  the starting point is here on github.  I'll document and cleanup that code as I go along Also looking for feedback on the compaction techniques I'm using for the Tweets, so please comment if you have suggestions

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$ git help pull
No manual entry for git-pull

$ git --version
git version 1.6.4.2

curl -O http://www.kernel.org/pub/software/scm/git/git-manpages-{YOUR VERSION}.tar.bz2

$ cat /etc/manpaths
/usr/share/man
/usr/local/share/man

sudo tar xjv -C /usr/local/share/man -f git-manpages-1.6.4.2.tar.bz2

Now you should get manpages when you issue something like git help merge

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The Setup

The test server setup:

• A Virtual Private server running on Rackspace cloud
• Ubuntu 9.04 (Jaunty Jackalope)

$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo locale-gen en_US.UTF-8
$ sudo apt-get install apache2-mpm-prefork php5 php5-dev mysql-server-5.0 mysql-client-5.0 php5-mysql
$ sudo a2enmod rewrite

• Installed latest Wordpress and added some test posts

Baseline Performance:

The Test URL's that http_load will draw from

$ cat pdxphp-test
http://67.23.47.195/
http://67.23.47.195/2010/02/test-post-1/
http://67.23.47.195/2010/02/test-post-2/
http://67.23.47.195/2010/02/test-post-3/
http://67.23.47.195/2010/02/test-post-4/
http://67.23.47.195/2010/02/test-post-5/

Run the test

$ http_load -parallel 5 -seconds 20 pdxphp-test
83 fetches, 5 max parallel, 1.74373e+06 bytes, in 20.0009 seconds
21008.8 mean bytes/connection
4.14982 fetches/sec, 87182.7 bytes/sec
msecs/connect: 80.6013 mean, 99.26 max, 71.974 min
msecs/first-response: 795.394 mean, 5495.6 max, 225.29 min
HTTP response codes:
  code 200 -- 82

Apache

Reduce the number of modules loaded

apache2ctl -t -D DUMP_MODULES

Loaded Modules:
 core_module (static)
 log_config_module (static)
 logio_module (static)
 mpm_prefork_module (static)
 http_module (static)
 so_module (static)
 alias_module (shared)
 auth_basic_module (shared)
 authn_file_module (shared)
 authz_default_module (shared)
 authz_groupfile_module (shared)
 authz_host_module (shared)
 authz_user_module (shared)
 autoindex_module (shared)
 cgi_module (shared)
 deflate_module (shared)
 dir_module (shared)
 env_module (shared)
 mime_module (shared)
 negotiation_module (shared)
 php5_module (shared)
 rewrite_module (shared)
 setenvif_module (shared)
 status_module (shared)

$ sudo a2dismod cgi
Module cgi disabled.
Run '/etc/init.d/apache2 restart' to activate new configuration!
sam@pdx-test:/etc/apache2/mods-enabled$ sudo apache2ctl start

Turn off htaccess

sudo vi /etc/apache/sites-enabled/wordpress

rm /var/www/wordpress/.htaccess

Now, how to really affect apache

<IfModule mpm_prefork_module>
    StartServers          5
    MinSpareServers       5
    MaxSpareServers      10
    MaxClients          150
    MaxRequestsPerChild   0
</IfModule>

<IfModule mpm_prefork_module>
    StartServers          1
    MinSpareServers       1
    MaxSpareServers       5
    MaxClients            5
    MaxRequestsPerChild   1000
</IfModule>

The Results thus far

MySQL

If you don't use it, Turn it off

skip-innodb
skip-bdb

# used for holding built indexes
key_buffer              = 16M
# largest query that is cache-able
query_cache_limit       = 1M
# used for caching queries
query_cache_size        = 16M

# used for holding built indexes
key_buffer                = 4M
# largest query that is cache-able
query_cache_limit       = 500K
# used for caching queries
query_cache_size        = 8M

mysql> SHOW STATUS WHERE Variable_name LIKE 'Key_blocks_%' OR Variable_name LIKE 'Qcache_%';
+-------------------------+----------+
| Variable_name           | Value    |
+-------------------------+----------+
| Key_blocks_not_flushed  | 0        |
| Key_blocks_unused       | 13369    |
| Key_blocks_used         | 27       |
| Qcache_free_blocks      | 4        |
| Qcache_free_memory      | 16326632 |
| Qcache_hits             | 5969     |
| Qcache_inserts          | 95       |
| Qcache_lowmem_prunes    | 0        |
| Qcache_not_cached       | 410      |
| Qcache_queries_in_cache | 46       |
| Qcache_total_blocks     | 106      |
+-------------------------+----------+
11 rows in set (0.00 sec)

The Final result of our tinkering

$ http_load-parallel 5 -seconds 20 pdxphp-test
137 fetches, 5 max parallel, 4.69493e+06 bytes, in 20 seconds
34269.6 mean bytes/connection
6.85 fetches/sec, 234747 bytes/sec
msecs/connect: 80.6284 mean, 96.353 max, 73.043 min
msecs/first-response: 276.766 mean, 447.707 max, 225.995 min
HTTP response codes:
  code 200 -- 137

Links:

• http://emergent.urbanpug.com/?p=60
• http://emergent.urbanpug.com/?p=61

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$ vnstat -m

 eth0  /  monthly

   month         rx      |      tx      |   total
-------------------------+--------------+--------------------------------------
  Aug '09       7.00 GB  |     8.48 GB  |    15.48 GB   %::
  Sep '09      14.98 GB  |    15.75 GB  |    30.72 GB   %%%::::
  Oct '09      31.70 GB  |    14.79 GB  |    46.50 GB   %%%%%%%%:::
  Nov '09      45.46 GB  |    14.64 GB  |    60.10 GB   %%%%%%%%%%%:::
  Dec '09      73.71 GB  |    15.40 GB  |    89.11 GB   %%%%%%%%%%%%%%%%%%::::
  Jan '10      66.25 GB  |    16.89 GB  |    83.14 GB   %%%%%%%%%%%%%%%%::::
-------------------------+--------------+--------------------------------------
 estimated     94.97 GB  |    24.21 GB  |   119.18 GB

sudo apt-get install vnstat

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• ease of install and use for someone new to all this technology
• cross platform versions available for Windows and Linux flavors including OS X
• extensibility In particular, Firefox and Netbeans.  As the user grows comfortable with these tools, they will discover that they contain many features to aid in web development.  (firefox: firebug, web-dev toolbar   netbeans: integrated source control, xdebug, etc)

Firefox

Install

XAMPP

Install on Windows (windows 7 64bit edition shown)

• Install apache as service
• Install mysql as service

Netbeans Editor

Netbeans Download

Configure after Install

Apply Updates

[caption id="attachment_279" align="alignnone" width="638" caption="Go to Help > Check For Updates"]

[/caption]

Test

Now create a new PHP application project called {YOUR NAME}-week1

Place the project in the XAMPP htdocs folder

Confirm the URL your project will be found at. (In our case, Netbeans should make the right guess here, so just confirm and click 'Finish'

Editor Will Open and Netbeans will automatically create a starter index.php file for you

Clean up some unneeded windows

close these windows (you can always get them back later if you like)

• navigator
• files
• services
• palette

Now to make a few edits and create a new file so we can start to get familiar with the IDE.

Add some PHP

See the file in a browser by clicking the green Play (>) button on the toolbar.  The Browser should open at the URL for the file.

create another file called new-file.php

• Menu: File > New File
• Choose category PHP, File Type PHP Web Page
• Next
• Change the filename to new-file.php
• Finnish

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Get the data

Step I: Pull the establishment records from the MCHD site

Step II: Pull the inspection scores for the gathered establishments from the MCHD site.

Step III: Geocode the Establishment Records using Google

Step IV: Display the Establishments on something akin to a heat-map

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