[as] » Web & Programming http://www.alexschreyer.net AEC CAD, Timber Engineering and more... Thu, 02 Sep 2010 02:40:30 +0000 en hourly 1 http://wordpress.org/?v=abc A lightweight WordPress page http://www.alexschreyer.net/programming/a-lightweight-wordpress-page/ http://www.alexschreyer.net/programming/a-lightweight-wordpress-page/#comments Thu, 11 Feb 2010 21:46:44 +0000 Alex http://www.alexschreyer.net/?p=2102

I had read about this trick before but had never had a need to try it out – until now. So here’s a nifty trick for any self-hosted WordPress installation:

If you want to add a webpage outside of a WordPress installation that has its own design, yet relies on some of the functions of the main WordPress installation (such as the loop), then you can simply create a “WordPress-enabled” page by adding the following PHP statement to the top of the page:

require('../wp-blog-header.php');

By doing this, WordPress will be loaded with the page while the template will not. It will also not show up anywhere in the WordPress site as it is not a post or a page. You can then go ahead and invoke any WordPress core or plugin function and use its data.

In my case, this worked well for an LCD “news display” for our building. I guess, you could also use this approach for a mobile-enabled site (although there are nice WordPress plugins that do this well. In any case, here is a sample of a WordPress-enabled “index.php” file located outside the wordpress installation. To modify it for your needs, simply adjust the path to wp-blog-header.php and you are good to go.

<?php
  /** Loads the WordPress Environment to have access to functions */
  require('../wp-blog-header.php');
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>My lightweight wordpress page</title>
  </head>
  <body>
    <h1>News</h1>
    <ul>
      <?php query_posts($query_string . '&cat=3&posts_per_page=5'); ?>
      <?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>
      <li><?php the_title(); ?></li>
      <?php endwhile; else: ?>
      <li>No news at this time.</li>
      <?php endif; ?>
    </ul>
  </body>
</html>

See the image on top of this post for a sample of our installation. You can also look at the “live” version here (optimized for a 720p widescreen LCD TV).

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]]> http://www.alexschreyer.net/programming/a-lightweight-wordpress-page/feed/ 0 Liquid Page – A bookmarklet to rearrange webpages http://www.alexschreyer.net/programming/liquid-page-a-bookmarklet-to-rearrange-webpages/ http://www.alexschreyer.net/programming/liquid-page-a-bookmarklet-to-rearrange-webpages/#comments Mon, 07 Dec 2009 21:33:22 +0000 Alex http://www.alexschreyer.net/?p=2010

I was once again changing the design of one of my websites when I realized that it would be great if I could just move things around on a page to preview the changes – without any coding. As it turns out, there is a solution to that problem: A bookmarklet and a few lines of JavaScript did the trick. Using jQuery and its UI extension, this actually turned out to be rather simple to implement.

Drag the link (“LIQUID PAGE”) shown below to your browser’s bookmarks toolbar. You can then use it on any web page. Simply load the page and then click the link. Be aware: You cannot try the functionality out on this page by simply clicking the link (it’s in an iframe). Please also note that there is a slight delay after clicking while some Javascript (i.e. jQuery) is being loaded – just wait for the confirmation dialog.

So what can you do with this? Beyond the obvious tweaking of existing web page designs, it should not be forgotten that this may hold potential for playing tricks on unaware browser users. It is – of course – also fun to just reorder (read: destroy) a well-known page design…

Before:

Screenshot - 12_8_2009 , 09_42_38

After:

Screenshot - 12_8_2009 , 09_49_05


Updates:

  • I added a function that removes all “overflow” properties (after user confirms). Therefore everything can be moved everywhere on a page. Just be aware that you cannot test nested DIVs this way. Also, the page layout may break due to overflowing text.

Caveat: Works best with Firefox, Chrome, Safari – as usual.

Thanks: The code is based on the jQuery UI ThemeRoller bookmarklet implementation.

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]]> http://www.alexschreyer.net/programming/liquid-page-a-bookmarklet-to-rearrange-webpages/feed/ 4 Follow me! http://www.alexschreyer.net/misc/follow-me/ http://www.alexschreyer.net/misc/follow-me/#comments Fri, 13 Nov 2009 05:00:20 +0000 Alex http://www.alexschreyer.net/?p=1979 2Chirp, chirp… While I was figuring out how to make best use of all things Web 2.0, I found that Twitter is a great way for me to broadcast quick news items related to my blog’s topics (AEC-CAD, timber engineering, design and web stuff). So whenever something is too short for a blog post but it does not deserve to be plowed under in my inbox, then you can be sure I’ll post it to my Twitter account.

To follow those posts, either click on “follow” in Twitter:

http://twitter.com/alexschreyer

Or subscribe to my Twitter RSS feed:

http://twitter.com/statuses/user_timeline/21881607.rss

Enjoy!

P.S.: Of course, you can also subscribe to this site’s various RSS feeds using the buttons at the top of this page.

11

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]]> http://www.alexschreyer.net/misc/follow-me/feed/ 0 Optimizing Google http://www.alexschreyer.net/programming/optimizing-google/ http://www.alexschreyer.net/programming/optimizing-google/#comments Mon, 29 Jun 2009 06:19:29 +0000 Alex http://www.alexschreyer.net/?p=1725 docs_139704c_solve_setup_en

As announced in their latest blog post, Google has just released an optimization feature for their online spreadsheets (which, of course, are part of Google Docs). With this new feature, linear optimization problems can be solved easily. This is a great feature and makes online spreadsheets even more Excel-like and usable. Here are some of the features:

  • Minimization or maximization of target cell, but no target value optimization. TIP: Minimize the difference to a target value if you need this.
  • Select (unlimited?) cells as design variables. Restriction to positive values is possible.
  • Add (unlimited?) constraints. These can be “<=”, “=” or “>=”. Since the dialog has no scroll function, the number of constraints is apparently limited by the screen height.
  • Due to the nature of the optimization algorithm, only linear problems can be computed. This means that formulas may not contain power functions or decision-based formulas (IF-THEN).

I haven’t tried this feature out yet on a real problem, but my main performance question would be whether the calculation uses Javascript in the local browser (likely) or uses Google’s server resources, which may speed things up  on a large problem.

For more help and information on this feature, look at the relevant Help page. And if you need an optimization solution for Excel spreadsheets that is based on Genetic Algorithms, check out my handy tool.

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]]> http://www.alexschreyer.net/programming/optimizing-google/feed/ 0 My semi-annual computer cleanup (a to-do list for everyone else) http://www.alexschreyer.net/programming/my-semi-annual-computer-cleanup/ http://www.alexschreyer.net/programming/my-semi-annual-computer-cleanup/#comments Wed, 27 May 2009 02:53:26 +0000 Alex http://www.alexschreyer.net/?p=1655 WinDirStat main window

WinDirStat main window

Now that the semester is over and all the grades are in, it is time for me again to clean up my computer before summer work starts. It is simply amazing how much that machine get filled with stuff over time. Add to that that my hard disk is small by today’s standards and I have my work cut out for me.

Since this may be of help for others, here is my to-do list when I clean my machine. Since I am running a Windows machine, all of those apply to Windows only.

  • Uninstall unused software
    I try out a lot of software and often forget to uninstall those right away. My uninstall tool of choice is the Revo uninstaller. It not only runs the software-supplied uninstaller but also checks for connected files and registry settings.
  • Run a disk cleanup
    That’s always a good idea. Run the Windows cleanup program as a baseline and then run CCleaner for more options and possibly a registry scan.
  • Find and cleanup big files
    I find the main space problem on my harddisk comes from huge files. Finding those is often a good step in chasing down which program stores large amounts of data. I use WinDirStat for this. It is a small software that lists large folders and files in a treeview and – especially useful – in a colorful diagram. This is how I found out about many of the other tips in this list.
  • Defragment drive
    You should do this regularly anyways. In my case I couldn’t do that until I had some time since I had to free up some space on my harddisk first (Windows’ defragmenter needs 15% free space to run). I also use Defraggler since it can defragment individual files. One tip: Disable hibernation (in your computer’s power settings) and set the pagefile to zero (right-click on My Computer and look under Properties) before you defragment. Those two files (hiberfil.sys and pagefil.sys) can be huge and are locked otherwise.
  • Cleanup MS Outlook archive and/or backup files and then defragment those
    Depending on how you use Outlook (if you do), it may be wise to delete old items. You can easily do so by running an advanced find (right-click on folder name in Outlook) over your “Personal Folders” file or your “Archive” file (if you have archiving enabled). I typically delete old items that are at least three years old.
  • Cleanup iTunes
    You may want to check iTunes for leftover podcasts, duplicate movies etc. Then delete those and maybe change the settings to only store the latest version of your subscribed podcasts.
  • Delete Picasa originals
    If you are happy with how Picasa modifies your images, then there’s no need to keep backups (I burn my original files on CD-ROMS as added safety anyways). Do a search for folders named “Originals” or “.picasaoriginals” and then delete those. You can use Windows’ search function but you’ll have to make those folders visible first since they are hidden (in any explorer window go to Tools > Folder Options…).
  • Malwarebytes anti-malware
    You should check for malware every once in a while anyways. I ran Microsofts’ little program which didn’t find anything. Then I tried Malwarebytes’ software which found the little bugger. Also do a check with Ad-aware.
  • Apple installers
    For whatever reason, Apple decided to cache every single installer for iTunes, Quicktime, Safari etc. for the past years on my harddrive. They are in folders called “Installer Cache”. You can spot them easily using WinDirStat and then safely delete at least the old versions.
  • Google Desktop index file
    This turned out to be a huge space hog on my harddisk. It may be a good idea to uninstall google desktop and reinstall. This way, the index gets rebuilt and old leftover items get removed. I also found that the index was significantly contributing to my harddrive fragmentation. You might need to manually remove the index files – mine didn’t clean up after an uninstall. Again, spot them using WinDirStat (They are under “Documents and Settings > All Users”.
  • Video temp files
    If you burn a lot of DVDs (of your family movies for example), look for temporary files or burn images. Video software often stores a full copy of the DVD on the harddisk before it burns the DVD itself.
  • System restore
    Final tip: You can reduce the amount of space that system restore uses by looking under the My Computer properties. Don’t turn it off, it’s a useful feature!
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]]> http://www.alexschreyer.net/programming/my-semi-annual-computer-cleanup/feed/ 3 Running multiple sites on shared hosting (with some DNS and HTACCESS magic) http://www.alexschreyer.net/programming/running-multiple-sites-on-shared-hosting-with-some-dns-and-htaccess-magic/ http://www.alexschreyer.net/programming/running-multiple-sites-on-shared-hosting-with-some-dns-and-htaccess-magic/#comments Fri, 22 May 2009 11:00:33 +0000 Alex http://www.alexschreyer.net/?p=1616 The worlds network

Plugged (Image by saschaaa)

I recently had the need to set up several different websites in one (hosted, shared) webspace. While this by itself is trivial there was a catch: I had multiple domains that needed to be DNS forwarded (using CNAME) to this webspace. In essence, the functionality I needed was that once a user goes to one of those domains, he/she would get the site served from one of the subdirectories in my webspace.

This again were trivial if the domains had been hosted with the company that provides me with the webspace. But in my case, the domains could not be moved and therefore I needed the DNS forwarding. In case you run into a similar situation, here’s what you need to do:

  1. Make sure you have Linux/Apache.
    This method works with Linux and Apache. I don’t know how to do this with Windows since IIS doesn’t have a clean way to rewrite URLs.
  2. Get a static IP.
    This is usually not included in a cheap, shared hosting plan. Some hosters offer those but mine didn’t. However, with my hoster (1and1.com), I was able to purchase an SSL certificate, which gave me a dedicated IP.
  3. Set up subdirectories and add URL rewriting
    Set up one subdirectory per site and add the site content into these. Then add a .htaccess file into the root of the webspace and add the following lines. Of course you’ll have to modify them to your need.
RewriteEngine on
Options +FollowSymLinks
RewriteBase /
# Site 1
RewriteCond %{HTTP_HOST} ^sub1.site.com$ [NC]
RewriteCond %{REQUEST_URI} !^/subdirectory1/.*$
RewriteRule ^(.*)$ /subdirectory1/$1 [L]
# Site 2
RewriteCond %{HTTP_HOST} ^sub2.site.com$ [NC]
RewriteCond %{REQUEST_URI} !^/subdirectory2/.*$
RewriteRule ^(.*)$ /subdirectory2/$1 [L]


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]]> http://www.alexschreyer.net/programming/running-multiple-sites-on-shared-hosting-with-some-dns-and-htaccess-magic/feed/ 4 Say Something! http://www.alexschreyer.net/programming/say-something/ http://www.alexschreyer.net/programming/say-something/#comments Sun, 08 Mar 2009 19:05:26 +0000 Alex http://www.alexschreyer.net/?p=1314 I just installed IntenseDebate on this site. It is a comment management system that is far more flexible than what I had so far. Threading is implemented (without me having to fiddle with the code and making everything work with WordPress 2.7 comments) and RSS subscription is nicely implemented. Commenters (and comments) can also now be voted on. Pretty nice system. Apparently I am not the only one using it – Obama likes it, too.

So if you have something to say about any of my posts (or some of the pages), go right ahead and debate intensely!

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]]> http://www.alexschreyer.net/programming/say-something/feed/ 1 Everything is Data http://www.alexschreyer.net/cad/everything-is-data/ http://www.alexschreyer.net/cad/everything-is-data/#comments Wed, 16 Jul 2008 03:30:24 +0000 Alex http://www.alexschreyer.net/?p=379

Even beyond the great music, Radiohead’s latest video “House of Cards” is simply amazing. And that for two reasons:

100% data-driven visuals. The entire music video was produced without the use of a camera. Instead, three kinds of (near- and far-range) laser scanners were used to capture the artists and several environments. That’s just great fun from an engineering standpoint.

All data and code are open source. Not only are both the raw data AND the processing code freely available on Google Code, fans (at least the tech-savvy kind) are encouraged to remix the data and make their own visualizations.

So if you feel like downloading 1/2 GB of pointcloud-data or are just interested in watching the “Making of…”, go to the Google Code page for more infos:

RA DIOHEA_D / HOU SE OF_C ARDS – Google Code

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]]> http://www.alexschreyer.net/cad/everything-is-data/feed/ 0 Explorations in the Infrared Spectrum http://www.alexschreyer.net/programming/explorations-in-the-infrared-spectrum/ http://www.alexschreyer.net/programming/explorations-in-the-infrared-spectrum/#comments Mon, 16 Jun 2008 05:00:05 +0000 Alex http://www.alexschreyer.net/?p=309 Me in false color IROkay, okay, this one is a bit geeky, but it’s fun so I had to try it. I don’t remember how I found this, but I saw somewhere that you can easily turn your $10 webcam into an infrared camera. Since I never ventured into the infrared spectrum with my film-based camera, this sounded like a great way to expand my photographic capabilities – at a rather low resolution, though.

Instead of lengthy instructions (which you can find here), I’ll just give you a short rundown on how to do this and leave you up to trying this for yourself. Here are the steps:

  1. Get a webcam. I believe anyone will do but I have found that the ball-shaped ones might be easier to work with than others due to their simplicity.
  2. Take it apart and look for the CCD chip. This is where the image gets acquired, so it’ll usually be in the center of the circuit board below the lens. (If you have a ball-shaped cam, then skip this step since you likely have a filter that’s attached to the underside of the lens, which screws out easily)
  3. Either below the lens or above the CCD chip is a glass plate that is coated with an IR-blocker. You need to get rid of that one. Either pry it out entirely or scratch off the coating. Try not to scratch the lens.
  4. Reassemble the camera and reconnect to your computer. At this point, you should see an image with colors that resemble the color shift you get with an old slide. You are now seeing visible and IR combined.
  5. Should have told you this earlier, but you need at this point an IR filter that blocks out visible light. Two ways to get one: 1) Take the blackened end of a color negative film and cut it to size to cover the lens on the outside or the inside. 2) Order a quite inexpensive (and more precise) plastic filter. I got mine from B&H Photo.
  6. Connect the camera and look at the incoming images. All visible light is now filtered out and you see infrared only.

The result is an image like this one:

IR Tree

Unfortunately the resolution and image quality is limited by what your camera can do, which is usually not much in terms of pixels and lens quality. If you need better quality, then feel free to modify your digital SLR (or video camera) in a similar (but more expensive) fashion.

Below is some of the fun you can have with this now. Be forewarned, this is not a thermal imaging camera – at least not for common household temperatures. The camera will, though, pick up heat above roughly 1400 degrees C (since the upper cutoff of these cameras is typically at a wavelength of 1700 nm). Check your oven heater coils for an example of this.

Me in false color IR IR Tree Lamp comparison Colors disappear Veins appear Fluorescent Light Test your money Night vision False color lamp comparison

(click any image for a description)

It gets a bit more technical when we apply false colors to the video. This allows to distinguish a bit better between slight variations. In the example below, an inverted HSB scale was mapped to the black-and-white image:

False color lamp comparison

And here is a video of another light source – a Christmas light chain:

Light Trails from Alexander Schreyer on Vimeo.

The video above was made (video acquisition and color conversion) and captured using a small piece of software I wrote in processing.

Links:

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]]> http://www.alexschreyer.net/programming/explorations-in-the-infrared-spectrum/feed/ 0 Searching the Mind-Map http://www.alexschreyer.net/programming/searching-the-mind-map/ http://www.alexschreyer.net/programming/searching-the-mind-map/#comments Mon, 05 May 2008 03:05:57 +0000 Alex http://www.alexschreyer.net/?p=310 While Google serves me well, I always enjoy new forms of search – especially the mind-map format. One of those just crossed my paths. Give it a try:

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