CSS equivalent of the center tag

Because I understand the temptation to sometimes just wrap a div in a damn <center> tag instead of messing around with auto margins, translatex(-50%), or any other such nonsense — and also partly as a future reference for myself — here is what I’ve found to be the CSS equivalent of the <center> tag.

.center-dammit {
    display: block;
    margin: 0 auto;
    text-align: center;
}

Caveat: I’ve not checked in depth so I’m sure there will be about a dozen exceptions. W3C, please sort this out for CSS4!

Of Ants and Rhinos

I recently opened a Pandora’s box when investigating incorporating LESS into a web project I’ve been working on. Long story short, I found myself having to compile Rhino into a jar I could execute.

Having installed Ant to perform the task, I ran the command and got the following exception:

C:\rhino1_7R5\xmlimplsrc\build.xml:129: src 'C:\rhino1_7R5\build\tmp-xbean\xbean.zip' doesn't exist.

Which is exactly what I want to be dealing with when investigating a CSS precompiler.

In any case I got to the bottom of the issue. So without further ado, here is…

The definitive list of steps for compiling Rhino

  1. Download the source from Rhino’s website
  2. Unzip it somewhere (let’s say, C:\rhino1_7R5″)
  3. Download Ant (if you don’t already have it) from Apache’s website
  4. Install Ant (instructions here)
  5. Download the zip from the following URL: http://archive.apache.org/dist/xmlbeans/binaries/xmlbeans-2.5.0.zip
  6. Create a folder in C:\rhino1_7R5\build\” called “tmp-xbean”
  7. Paste the zip from step 5 into this folder and rename it to “xbean.zip”
  8. Open a command prompt in C:\rhino1_7R5
  9. Run the command “ant jar”

For those interested, I worked this out by taking a look in the Ant build file for “xmlimplsrc”, which was the root of the error. This build XML file actually contains the location of the zip file which it’s failing to find. My guess is that it attempts to download it (install instructions are very unclear about the fact that they require an internet connection) and when that fails, your build fails. In my case it’s most likely due to my company network’s proxy restrictions.

I hope this helps.

Say what? Analysing speech at SAS

I rarely get to talk about my work at SAS since mostly it’s experimental research and development, and therefore kept fairly hush hush. Recently, however, I had to the opportunity to write a guest article for data-informed.com about a project I’ve been working on for the past few months.

Having partnered up with a Scottish speech-to-text company, we built a system which could take reams of audio, transcribe them, and then perform some pretty sophisticated text analysis to work out the people and locations mentioned in the audio (and what their connections were), as well as identifying any number of discussion topics.

The article itself is very high level, so you don’t need to be technical to understand it. It’s an introduction to the concept, and some of the applications for the method.

Click the image below to go read the article.

 

Speech to Analytics
http://data-informed.com/text-analytics-could-unlock-strategic-value-hidden-speech/

 

 

Gradle from behind a proxy, part deux

In July I wrote a post documenting how to build a project in Android Studio from behind a proxy. Essentially you need to tell Gradle Studio your proxy settings.

As of updating to Android Studio 1.0, the issue has come back! After a combination of swearing and research I’ve found the missing necessary steps.

So the new definitive steps for getting Gradle working from behind a proxy

  1. Navigate to the “.gradle” folder in your user directory (e.g. C:\Users\bob\.gradle)
  2. Create a “gradle.properties” file
  3. Edit the file to have the following contents (replacing your own values)
    systemProp.http.proxyHost=<proxy_host> 
    systemProp.http.proxyPort=<port> 
    systemProp.http.proxyUser=<user> 
    systemProp.http.proxyPassword=<password> 
    systemProp.http.nonProxyHosts=*.nonproxyrepos.com|localhost
  4. Go to Files > Settings > HTTP Proxy
  5. Select “Manual proxy configuration”
  6. Enter the same details you filled into the grade.properties file above: host, port, etc
  7. Tick “Proxy authentication”
  8. Fill in your username and password

Tadaa. This should get you back up and running again.

Exposing a VM on hosted WiFi hotspot for Google Glass

Background

Google Glass is famously frustrating to connect to a WiFi network. It doesn’t handle captive portals, or WiFi using Enterprise WPA2. I’ve also had consistent issues using MyGlass and QR codes to connect to Wifi.

I found myself in a situation where I had to connect Glass to a WiFi network on which a virtual machine was visible. My work’s corporate network was out of the question – it uses Enterprise WPA2. I would have connected my phone to the network and shared it to Glass via Bluetooth, but that was nixed for security reasons. So I had to set up a new network exclusively for Glass.

First thought – let’s just set up an Ad-Hoc wireless network on my laptop! But no, alas Android doesn’t support connecting to ad-hoc networks. Universe, why do you hate me so?

The solution

The solution involves a wireless-enabled Windows machine and VirtualBox – a program for running virtual machines.

An alternative to creating an ad-hoc network on your machine is to create a Wireless Hosted Network. This basically allows your Windows machine to act as a WiFi hotspot which can pass through a (wired) internet connection if you so wish.

My approach was to create a hosted network, connect my phone to it, then pass on the connection via Bluetooth. An admittedly insane chain of connections, but it’s all I had.

Create the WiFi network

  1. Open the Start menu and type “cmd”
  2. Right click and select “Run as Administrator”
  3. Type the following command:
     netsh wlan set hostednetwork mode=allow ssid=mynetworkid key=mypassword

Start the network

You’ll have to do this every time you start the machine, or alternatively set up a batch script to run this on startup.

  1. Type the following command:
     netsh wlan start hostednetwork

You should now see “mynetworkid” (or whatever you called it) in your list of wireless networks.

Create your VirtualBox image

  1. Install VirtualBox
  2. Create a new virtual machine (steps available here) – I’ve chosen to use a linux install
  3. Once your VM is created, go to Settings and choose Network
  4. Set up a Bridged Adapter
    1. Enable a network adapter
    2. Select Attached To: “Bridged Adapter”
    3. Select “Microsoft Virtual WiFi Miniport Adapter” as the Name – this is where the network you’ve just created is hosted.
  5. Start your VM up

Check connectivity

  1. On your Windows machine, open a command line and type:
     ipconfig

    A list of networks should be shown – one of which should be called “Wireless LAN adapter Wireless Network Connection”. Note down the first 9 digits of the IP address listed under this e.g. 192.168.173

  2. In your VM, run the following command:
     /sbin/ifconfig

    And note the networks and IPs that are listed. If no other networks were set up, your eth0 network should have an IP where the first 9 digits of the IP address matches those you noted down earlier. That means that they’re running on the network.

  3. For a laugh, ping your VM from your Windows machine, using the IP address from the previous step. This will confirm that your VM is addressable and contactable from your Windows machine. Given that your Windows machine is now broadcasting a wireless network, that means that the VM should be contactable to anyone on the network too.

Ping your VM from your Android device

As the penultimate proof, try pinging your VM from your Android device.

  1. Install an app which will let you run a ping command (I used PingTools)
  2. Ping the IP address you pinged previously

This should also show a response. And now we’re on the home straight.

Write some Glass code to contact your VM

You can do this however you wish. I wrote some very simple ping code to prove that Glass – once paired to my phone – was sharing the same internet connection as the phone, and the Windows machine, and as the VM.

There are tons of ways of doing it – for example:

InetAddress server = InetAddress.getByName("192.168.173.123");
if (server.isReachable(10000))
{
         // It’s contactable!
         celebrate();
}

Conclusions

That was much, much harder than it should have been. Alternatives I didn’t attempt:

  • Buying a router and broadcasting my corportate ethernet through it
  • Getting a company-approved phone that could have connected to the Enterprise network
  • Binning my Google Glass

PS – Many thanks to this post which acted as a great reference. It’s also worth checking out if you need to pass through internet via your hosted network.

How to invoke a SAS macro stored in a catalog

Having not done the Advanced Base SAS certification, this was a nightmare to work out. I’m documenting it here for my own future use, and to help anyone else who found themselves in the same situation as me.

What situation was that?

SAS Social Network Analysis can create networks from input data, and to do so it makes use of a pre-compiled “link macro” which is bundled with SNA. This link macro needs to be invoked from a base SAS program, but to do that, you need to tell SAS where to find it.

Note – There were literally zero Google hits for the exact name of this link macro. In case you’re curious, it’s called % sfs_net_main_link_macros.

Anyway I eventually found the location of these macros, in a catalog file.

Note – Not easy to find, and not documented. If anyone is in the same situation as me, it was in my <SASHome>\SASFoundation\9.3\snamva\macros folder. The macros are compiled into the sasmacr.sasb7cat file.

So I have a catalog file, how do I invoke the macro held in it?

Once you know, it’s very very simple.

  1. Copy the catalog file into your working directory
  2. Add a libname statement pointing to this working directory
  3. Use the SASMSTORE option

In other words your code should have the following statements:

libname mylib "D:\mylocation";
OPTIONS MSTORED SASMSTORE=mylib;

This will make the next invocation of the macro succeed, since SAS now knows it’s in your libname directory.

Removing duplicate rows in base SAS

If you ever need to remove duplicate rows from a SAS dataset, here’s an approach I use quite often.

Get your data.

Let’s assume it’s in the following format:

ID Name
123 John
456 Bob
123 John

Sort your data.

/* Step 1 - Sort data */
proc sort data=my_lib.my_dataset;

   /* Sort by a field which you want to be unique, 
   and which will be the same for duplicate rows */
   by id; 

run;

Which should give you the following:

ID Name
123 John
123 John
456 Bob


Remove Duplicates

Now that the data is in order, we can remove the duplicates, by only ever keeping the first entry which matches our unique ID.
-.

/* Step 2 - Get rid of duplicates */
data my_lib.my_dataset;

   /* Iterate through this dataset row by row */
   set my_lib.my_dataset;
   /* Grouping each row by the field we sorted on */ 
   by id; 
   /* And only keep a row if it’s the first */
   if first.id; 

run;

ID Name
123 John
456 Bob


Tadaa!

What happened there?

This approach has 3 facets:

  1. Grouping
  2. SAS’ special first.variable
  3. SAS’ feature of only appending (or “outputting”) a row to a dataset if there are no non-assignment statements which evaluate to false.


Grouping: So we effectively rearranged our data so that all identical IDs were grouped together. Given that the rows are identical and you only want to keep one of them, we choose to keep the first of each group.

First.variable: During execution, SAS will iterate through each row of my_data_set and adding it to a new dataset (which it will eventually overwrite my_data_set with). During each iteration, if it hits a row with the first use of an ID value (for example, 123), it will set first.id to true. On the next run, because it’s already seen the value 123 before, first.id is set to false. This gives us a handy flag which will only ever be toggled on unique rows.

Funny Statement Stuff: So how do we flag to SAS that when this value is set to true, to keep the row? When evaluating a data row if at any point we make any floating statement (i.e. not assigning a variable, or in an if or do loop) which evaluates to false, SAS will take that as a sign that it shouldn’t output that row i.e. in this case, it shouldn’t keep it.

So in simple terms, we’re saying – if you’ve seen this value before, don’t save it again.

Debugger this! Debugging an Android Service

I recently found out that I couldn’t hit any breakpoints in an Android Service I was developing. I found that this was easily sorted by adding the following line:

android.os.Debug.waitForDebugger()

This approach was suggested on various websites including StackOverflow and HelloAndroid amongst many. Great.

I found out much later than when I ran the code “in the wild” i.e. in a production environment unattached to a debugger, my application was failing.

Long story short, this is caused by the waitForDebugger() call, which will cause any code following your invocation to not be executed if there is no debugger.

I suppose I should have realised, but I had assumed that maybe the runtime or the call itself would be clever enough to know whether the application was in debug mode at all, and ignore it if it wasn’t.

But thankfully, we can do that:

if (android.os.Debug.isDebuggerConnected)
{
    android.os.Debug.waitForDebugger()
}

So I’d recommend this is the approach you take over having to remember to take that call out.

Android Studio – Fix sudden unresolved symbols

Android Studio is a fickle beast. At times surprisingly clever and useful, and other times a flaky nightmare.

The most recent issue I came across was when a Google Glass project suddenly stopped building with unresolved symbol errors. This manifests itself as all your “com.google.android.glass.*” imports failing, and the resulting use of any object from those libs causing compilation errors.

What the hell, Android Studio??
What the hell, Android Studio??

How to fix it

Eventually I checked my project dependencies and explicitly added the GDK as a library. Bingo, that sorted it out.

  1. Copy the gdk.jar

    This will be in your Android SDK directory, under /add-ons/addon-google_gdk-google-19/libs

  2. Paste it into the libs folder in your project directory

    e.g. C:\Projects\MyProject\app\libs

  3. Go to File > Project Structure
  4. Select your module (default name is app)
  5. Click the Dependencies tab
  6. Click the “+” sign
  7. Navigate to the libs folder and select the gdk.jar file
  8. OK through everything

I have zero idea why the issue suddenly arose. As with so many other issues I’ve come across in my short time developing for Android, I’ve learned to FDM: fix, document, and move on.

Using Gradle from behind a proxy

By default Android Studio uses Gradle to build Android projects. This means Android Studio always needs a connection to the internet to check for and retrieve dependencies. If you’re developing from behind a proxy (as I am) then you’ll have to explicitly tell Gradle the proxy details to allow it to connect to its servers.

Steps to fix

  1. Navigate to the “.gradle” folder in your user directory (e.g. C:\Users\bob\.gradle)
  2. Create a “gradle.properties” file
  3. Edit the file to have the following contents (replacing your own values)
systemProp.http.proxyHost=<proxy_host>
systemProp.http.proxyPort=<port>
systemProp.http.proxyUser=<user>
systemProp.http.proxyPassword=<password>
systemProp.http.nonProxyHosts=*.nonproxyrepos.com|localhost

Gradle should then succeed on the next build.

Note – thanks go to Steve Hanson for these steps.

Update 08 Dec 2014 – As of the update to Android 1.0, these steps are not enough! I’ve documented the new definitive list in this post.