Making Time Based Graphs with Chartist

I have been implementing some custom charts with Chartist recently.  Overall things have gone very well with some simple tweaks and fiddling to get things exactly how I want.  It is very nice to be be able to easily adjust the charts with CSS right in the normal site code.

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Problems with Java Based OS X Applications Hanging when Entering Text

So I found another problem with my new upgrade to OS X 10.11.  That is that the Java web application I was using, Adobe Ad Hoc Analysis in this case, would hard lock every time i tried to enter text in a text box.  The only solution was to force quit the application.  After much testing I found the culprit was the RescueTime helper applet.  Basically this applet gets Accessibility access so that it can inspect windows and record time used but is glitching on the java windows and causing the lock up.

There could be other programs causing the same issues even if you don't use RescueTime but are having the same problem.  To troubleshoot do the following.

• Close out of the java program that is locking up.
• Open System Preference > Security & Privacy > Privacy > Accessibility.
• Note with items are check and then uncheck them all.
• Restart your java program and attempt to reproduce the issue.
• If it is working correctly then quit, re-enable one item, and try again until you find the culprit.
• If you can't get around the error even with all Accessibility options off that you must have some other issue.

Anyway if you find any items fix the problem you can just leave them off though they might hinder there applications functionality.

OSX 10.11 Stuck On Grey Screen After Login

After upgrading to El Capitan yesterday I ran into an issue where my computer would boot up going through the loading bar and display the login screen if  enabled.  Upon logging in, or automatic login, the system would hang at a grey screen.  After some testing with the network I figured out that it was not actually locking up and would respond to traffic.

To determine if your issues is due to the same problem wither SSH into the computer once booted if remote login was enabled or boot to Recovery Mode  and launch the Terminal.  Then run the following to see recently logged errors.

tail /var/log/system.log | grep 'Segmentation fault'

Or if using the Recovery Mode terminal the following thought the drive name may be different.

tail /Volumes/Macintosh\ HD/var/log/system.log | grep 'Segmentation fault'

If either of these commands produce any results that you have found your problem.  The culprit is Unsigned Kernel Extensions or .kext modules.  In the good old days developers could just install these as needed to add code level kernel functionality but no for improved security OS X requires that all Kernel Extensions be signed by the developer.  This is overall a good thing because these are privileged and could easily lead to malicious behavior by untrusted sources.

Anyway the problem where is that the upgrade didn't disable the unsigned Kernel Extensions it found and instead just doest't load them.  This is fine and normally it would just mean that whatever applications depend on them would jus not work until updated but for whatever reason there are a few special cases that cause the login process to hang.  I ended up removing all the Virtual Box and Soundflower modules and then was able to boot without issue.  I have not tried to Re-install or upgrade wither yet but atlas my computer boots.

To remove these again go to the Terminal and do the following.  You will nee to authorize them with your administrative password.

sudo rm -Rf /System/Library/Extensions/Waco*
sudo rm -Rf /Library/Extensions/VBox*
sudo rm -Rf /Library/Application\ Support/VirtualBox/*
sudo rm -Rf /System/Library/Extensions/Soundflower*
sudo rm -Rf /var/folders/*

Again note the additional prefix if using the Recovery Mode ant that thedick name may be different.

sudo rm -Rf /Volumes/Macintosh\ HD/System/Library/Extensions/Waco*
sudo rm -Rf /Volumes/Macintosh\ HD/Library/Extensions/VBox*
sudo rm -Rf /Volumes/Macintosh\ HD/Library/Application\ Support/VirtualBox/*
sudo rm -Rf /Volumes/Macintosh\ HD/System/Library/Extensions/Soundflower*
sudo rm -Rf /Volumes/Macintosh\ HD/var/folders/*

Finally just reboot and enjoy.

Raspberry Pi B Crashing when Running on SD Card

I have been having surtax crashes with my Raspberry Pi B for a few months now and it is a very irritating intermittent issue.  The unit basically locks up and even on resetting the power it won't always turn back on, but rather just sit there with no lights and no display and I end of having to cycle the power 2-5 times to get it to start again.

Anyway, I finally figured out there it appears to be an issues with the SD card.  At first I thought that it was just an off brand card and the Raspberry Pi just didn't like it.  But after some testing and hands on trials I figured out that it appeared to be an actual problem with the electrical connection and even though the card seamed seated properly to poor connection would cause the card to be or become unreadable.  This was easy to verify by lightly pressing on the SD card and then turning on the Raspberry PI.  It turned right on and worked perfectly and as soon as I let go it died again.  I can't see any physical defects and the card looks to be seated and pressing firmly into the contacts but I guess it's not sufficient.

I found a simple solution, a simple light pressure chip clip/close pin on the SD-card solved the problem perfectly.  I added a bit of cloth above the SD card and ensured that the clasp was pressing just above the SD Card's contact points and placed it over the end of the Raspberry PI and it works like a charm.

XBian RC2 ASS Subtitles not Displaying in MKV Videos

Minor issues I found when updating to the current release of XBian on my Raspberry Pi B.  Namely that subtitles would not work from MKV videos.  Heres a simple fix for the issue.  SSH into the xbian and run the following:

sudo apt-get install libass5