Technology Tales

On upgrading from Fedora 13 to Fedora 14

My Fedora box recently got upgraded to the latest version of the distribution (14) and I stuck to a method that I have used successfully before and one that isn't that common with variants of Linux either. What I did was to go to the Fedora website and download a full DVD image, burn it to a disk and boot from that. Then, I chose the upgrade option from the menus and all went smoothly with only commonplace options needing selection from the menus and no data got lost either. Apparently, this way of going about things is only offered by the DVD option because the equivalent Live CD versions only do full installations.

However, there was another option that I fancied trying, but was stymied by messages about a troublesome Dropbox repository. As I later discovered, that would have been easily sorted, only for my opting for a tried and tested method instead. This was a pity because only two commands would have needed to be issued when logged in as root, and it would have been good to have had a go with them:

yum update yum
yum --releasever=14 update --skip-broken

These may have done what I habitually do with Ubuntu upgrades but trying them out either will have to await the release of the next version or my getting around to setting up a Fedora virtual machine to see what happens. The latter course of action might be sensible anyway to see if all works without any problems before doing it for a real PC installation.

Ridding Fedora of Unwanted Software Repositories

Like other Linux distributions, Fedora has the software repository scheme of things for software installation and updating. However, it could do with having the ability to remove unwanted repositories through a GUI, only it doesn't. What you need to do instead is switch to root in a terminal using the command su - and enter your root user password before navigating to /etc/yum.repos.d/ to delete the troublesome [file name].repo file. Recently, I needed to do this after upgrading to Fedora 14 or yum wouldn't work from the command line, which is the way that I tend to update Fedora (yum -y update is the command that I use because it automatically does all installations unattended until it is finished doing what's needed). The offending repository, or "Software Source" as these things are called in the GUI, belonged to Dropbox and even disabling it didn't make yum operate from the command like it should, so it had to go. Maybe Dropbox hasn't caught up with the latest release of Fedora, but that can be resolved another day.

Taking the sudo command beyond Ubuntu

Though some may call it introducing a security risk, being able to execute administrator commands on Ubuntu using sudo and gksu by default is handy. It's not the only Linux distribution with the facility, though, since the /etc/sudoers file is found in Debian and I plan to have a look into Fedora. The thing that needs to be done is to add the following line to the aforementioned file (you will need to do this as root):

[your user name] ALL=(ALL) ALL

One that is done, you are all set. Just make sure that you're using a secure password, though, and removing the sudo/gksu permissions is as simple as reversing the change.

Update on 2011-12-03: The very same can be done for both Arch Linux and Fedora, The same file locations apply too.

Turning off the admin bar in WordPress 3.1

Work on WordPress 3.1 is in full swing at the moment, though I initially thought that they were taking a little break after 3.0. From what I can see, many refinements are being made to the multi-blog functionality and behind-the-scenes work is ongoing on the administration screens too.

Another under-the-bonnet change has been to make WordPress less tied to MySQL, since the possibility of dropping in support for an alternative such as PostgreSQL is now a reality even if it isn't part of the default package. For now, it looks as if this will be plugin territory rather than default multi-database support, though that may become a sensible development in the light of Oracle's acquisition of MySQL and its sabre-rattling regarding Java patents. So far, the change to WordPress has affected my use of its database engine to power an offline version of my online photo gallery, but a quick spot of code editing sorted that issue.

One more obvious alteration will be the addition of a WordPress.com style administration bar to the top of all content and administration screens for a user who is logged into the system. Though it will be turned on by default, there will be the option of turning it off for those among who prefer things that way. All that will be needed for this is to add the following line near the top of wp-config.php:

define( "WP_SHOW_ADMIN_BAR", false);

The chance to see new additions like those above and be ready for is my main reason for following WordPress development. It's best to be ready instead of being surprised, though it has to be said that the blogging or CMS platform is a very polished one these days.

One reason why you cannot merge cells in Excel

One handy thing that I didn't realise that you could do with Excel until the last few months was the ability to share an open workbook between users and collate any changes that are made (it seems that a form of version control is behind this). From what I have seen, Excel seems to manage changes to shared spreadsheets rather well. When you save yours, it adds updates from other users and warns if any edits collide with one another. To activate it in Excel 2003, all that needs doing is for you to go to the Share Workbook entry on the Tools and tick the appropriate checkbox in the resulting dialogue box. In 2007 and 2010, look for the Share Workbook icon in the Review tab on the ribbon to get the same dialogue box popping up.

That's not to say that it doesn't have its restrictions, though. For example, I have found that the merging of cells is made unavailable, but that can be sorted by unsharing and resharing the workbook when no one else is using it. As to why cell merger is switched off by sharing, I have a few ideas. Maybe, they couldn't make it work reliably (can happen with large software development projects like the creation of a new version of Excel) or decided that it would have consequences for other users that are too inconvenient. Either way, we cannot merge cells in shared workbooks, and that's the way that things are for now. Some may not worry about this though, since they reckon that cell merging is undesirable anyway; well, don't go doing it in any spreadsheet that is likely to be read in by another program, or you could cause trouble.

Why go elsewhere when you can get it at Argos?

It is perhaps a sign of the technological times in which we live that even mainstream stores like Argos stock computing equipment these days. For instance, last weekend, I bought a Seagate Expansion 2 GB external hard drive in there for backing up my digital photo collection and never got to a local independent computer shop like I had planned to do. Maybe, it was the convenience and lack of fuss with a catalogue shop that swung it for me. In this case, the largest size at the other place was 1 GB according to its website anyway.

Other items bought from the pervasive chain have included a BlackBerry, a Vodafone mobile broadband dongle and an Asus Eee PC. All have done what I have asked of them and without any trouble, yet it does make me wonder about the threat to the specialist PC stores from their more mainstream competitors, and it isn't just Argos either. Tesco also tempts folk into their stores with technological goods, so I must own up to having a cheap DVD player from there.

In former times, I might have been lured into purchasing at online stores until the reality of dealing with inflexible delivery services took away the shine after a few years. After all, I'd prefer not to burden neighbours with taking delivery of any purchases. My current job offers the possibility of some home working so that might be an option for those things that do need delivering, but there remains a certain immediacy to going into a real shop for what you need and then to take it away on the day (having paid for it, of course) that is difficult to beat.

While I tend to decide what to get using my mind after doing some research, others may prefer the idea of getting some advice in a shop, which is where the specialists score. In fact, it may be the only way that they are going to cope with the onslaught from megastores like Argos and Tesco. All this reminds me that going to a local independent shop next time is in order because they cannot be doing brilliantly in these cash-straightened times.

Portable computing with the Asus Eee PC 1001 HA

Having had an Asus Eee PC 1001 HA for a few weeks now, I thought that it might be opportune to share a few words about the thing on here. The first thing that struck me when I got it was the size of the box in which it came. Being accustomed to things coming in large boxes meant the relatively diminutive size of the package was hard not to notice. Within that small box was the netbook itself, along with the requisite power cable and not much else apart from warranty and quick-start guides; so that's how they kept things small.

Though I was well aware of the size of a netbook from previous bouts of window shopping, the small size of something with a 10" screen hadn't embedded itself into my consciousness. Despite that, it came with more items that reflect desktop computing than might be expected. First, there's a 160 GB hard disk and 1 GB of memory, neither of which is disgraceful and the memory module sits behind a panel opened by loosening a screw, which leaves me wondering about adding more. Sockets for network and VGA cables are included, along with three USB ports and sockets for a set of headphones and for a microphone. Portability starts to come to the fore with the inclusion of an Intel Atom CPU and a socket for an SD card. Unusual inclusions come in the form of an onboard webcam and microphone, both of which I intend to leave in the off position for the sake of privacy. Wi-Fi is another networking option, so you're not short of features. The keyboard is not too compromised either, and the mouse trackpad is the sort of thing that you'd find on full-size laptops. With the latter, you can use gestures too, so I need to learn what ones are available.

The operating system that comes with the machine is Windows XP, and there are some extras bundled with it. These include a trial of Trend Micro as an initial security software option, as well as Microsoft Works and a trial of Microsoft Office 2007. Then, there are some Asus utilities too, though they are not so useful to me. All in all, none of these burden the processing power too much and IE8 comes installed too. Being a tinkerer, I have put some of the sorts of things that I'd have on a full-size PC on there. Examples include Mozilla Firefox, Google Chrome, Adobe Reader and Adobe Digital Editions. Pushing the boat out further, I used Wubi to get Ubuntu 10.04 on there in the same way as I have done with my 15" Toshiba laptop. So far, nothing seems to overwhelm the available processing power, though I am left wondering about battery life.

The mention of battery life brings me to mulling over how well the machine operates. So far, I am finding that the battery lasts around three hours, much longer than on my Toshiba but nothing startling either. Nevertheless, it does preserve things by going into sleep mode when you leave it unattended for long enough. Still, I'd be inclined to find a socket if I was undertaking a long train journey.

According to the specifications, it is supposed to weigh around 1.4 kg and that seems not to be a weight that has been a burden to carry so far and the smaller size makes it easy to pop into any bag. It also seems sufficiently robust to allow its carrying by bicycle, though I wouldn't be inclined to carry it over too many rough roads. In fact, the manufacturer advises against carrying it anywhere (by bike or otherwise) without switching it off first, but that's a common-sense precaution.

Start-up times are respectable, though you feel the time going by when you're on a bus for a forty-minute journey, and shutdown needs some time set aside near the end. The screen resolution can be increased to 1024x600 and the shallowness can be noticed, reminding you that you are using a portable machine. For that reason, there have been times when I hit the F11 key to get a full-screen web browser session. Coupled with the Vodafone mobile broadband dongle that I have, it has done some useful things for me while on the move so long as there is sufficient signal strength (seeing the type of connection change between 3G, EDGE and GPRS is instructive). All in all, it's not a chore to use, as long as Internet connections aren't temperamental.

An avalanche of innovation?

It seems that, almost despite the uncertain times or maybe because of them, it feels like an era of change on the technology front. Computing is the domain of many of the postings on this website, and a hell of a lot seems to be going mobile at the moment. For a good while, I managed to stay clear of the attractions of smartphones until a change of job convinced me that having a BlackBerry was a good idea. Though the small size of the thing really places limitations on the sort of web surfing experience that you can have with it, you can keep an eye on the weather, news, traffic, bus and train times so long as the website in question is built for mobile browsing. Otherwise, it's more of a nuisance than a patchy phone network (in the U.K., T-Mobile could do better on this score, as I have discovered for myself; thankfully, a merger with the Orange network is coming next month).

Speaking of mobile websites, it almost feels as if a free for all has recurred for web designers. Just when the desktop or laptop computing situation had more or less stabilised, along came a whole pile of mobile phone platforms to make things interesting again. Familiar names like Opera, Safari, Firefox and even Internet Explorer are to be found popping up on handheld devices these days along with less familiar ones like Web 'n' Walk or BOLT. The operating system choices vary too, with iOS, Android, Symbian, Windows and others all competing for attention. It is the sort of flowering of innovation that makes one wonder if a time will come when things begin to consolidate, but it doesn't look like that at the moment.

The transformation of mobile phones into handheld computers isn't the only big change in computing, with the traditional formats of desktop and laptop PC's being flexed in all sorts of ways. First, there's the appearance of netbooks, and I have succumbed to the idea of owning an Asus Eee. Though you realise that these are not full-size laptops, it still didn't hit me how small these were until I owned one.  They are undeniably portable, while tablets look even more interesting in the aftermath of Apple's iPad. Though you may call them over-sized mobile photo frames, the idea of making a touchscreen do the work for you has made the concept fly for many. Even so, I cannot say that I'm overly tempted, though I have said that before about other things.

Another area of interest for me is photography, and it is around this time of year that all sorts of innovations are revealed to the public. It's a long way from what, we thought, was the digital photography revolution when digital imaging sensors started to take the place of camera film in otherwise conventional compact and SLR cameras, making the former far more versatile than they used to be. Now, we have SLD cameras from Olympus, Panasonic, Samsung and Sony that eschew the reflex mirror and prism arrangement of an SLR using digital sensor and electronic viewfinders while offering the possibility of lens interchangeability and better quality than might be expected from such small cameras. Lately, Sony has offered SLR-style cameras with translucent mirror technology instead of the conventional mirror that is flipped out of the way when a photographic image is captured.  Change doesn't end there, with movie making capabilities being part of the tool set of many a newly launched compact, SLD and SLR camera. The pixel race also seems to have ended though increases still happen as with the Pentax K-5 and Canon EOS 60D (both otherwise conventional offerings that have caught my eye, though so much comes on the market at this time of year that waiting is better for the bank balance).

The mention of digital photography brings to mind the subject of digital image processing and Adobe Photoshop Elements 9 is just announced after Photoshop CS5 appeared earlier this year. It almost feels as if a new version of Photoshop or its consumer cousin is released every year, causing me to skip releases when I don't see the point. Elements 6 and 8 were such versions for me, so I'll be in no hurry to upgrade to 9 yet either, even if the prospect of using content aware filling to eradicate unwanted objects from images is tempting. Nevertheless, that shouldn't stop anyone trying to exclude them in the first place. In fact, I may need to reduce the overall number of images that I collect in favour of coming away with only the better ones. The outstanding question on this is: can I slow down and calm my eagerness to bring at least one good image away from an outing by capturing anything that seems promising at the time? Some experimentation but being a little more choosy can save work later on.

While back on the subject of software, I'll voyage in to the world of the web before bringing these meanderings to a close. It almost feels as if there are web-based applications following web-based applications these days, when Twitter and Facebook nearly have become household names and cloud computing is a phrase that turns up all over the place.  In fact, the former seems to have encouraged a whole swathe of applications all of itself. Applications written using technologies well-used on the web must stuff many a mobile phone app store too and that brings me full circle for it is these that put so much functionality on our handsets with Java seemingly powering those I use on my BlackBerry. Then there's the spat between Apple and Adobe regarding the former's support for Flash.

To close this mental amble, there may be technologies that didn't come to mind while I was pondering this piece, but they doubtless enliven the technological landscape too. However, what I have described is enough to take me back more than ten years ago, when desktop computing and the world of the web were a lot more nascent than is the case today. Then, the changes that were ongoing felt a little exciting now that I look back on them, and it does feel as if the same sort of thing is recurring though with things like phones creating the interest in place of new developments in desktop computing such as a new version of Window (though 7 was anticipated after Vista). Web designers may complain about a lack of standardisation, and they're not wrong, yet this may be an era of technological change that in time may be remembered with its own fondness too.

Exploring the option of mobile broadband

Last week, I decided to buy and experiment with a Vodafone PAYG mobile broadband dongle (the actual device is a ZTE K3570-Z) partly as a backup for my usual broadband (it has had its moments recently) and partly to allow me to stay more connected while on the move. Thoughts of blogging and checking up on email or the real-time web while travelling to and from different places must have swayed me.

Hearing that the use of Windows or OS X with the device had me attempting to hook up the device to Windows 7 running within a VirtualBox virtual machine on my main home computer. When that proved too big a request from the software setup, I went googling out of curiosity and found that there was a way to get the thing going with Linux. While I am not so sure that it works with Ubuntu without any further adjustments, my downloading of a copy of the Sakis3G script was enough to do the needful, and I was online from my main OS after all. So much for what is said on the box...

More success was had with Windows 7 as loaded on my Toshiba Equium notebook, with setting up and connections being as near to being effortless as these things can be. Ubuntu is available on there too, courtesy of Wubi, and the Sakis3G trick didn't fail for that either.

That's not to say that mobile broadband doesn't have its limitations, as I found. For instance, Subversion protocols and Wubi installations aren't supported, but that may be a result of non-support of IPv6 than anything else. Nevertheless, connection speeds are good as far as I can see, though I yet have to test out the persistence of Vodafone's network while constantly on the move. Having seen how flaky T-Mobile's network can be in the U.K. as I travel around using my BlackBerry, that is something that needs doing, yet all seems painless enough so far. However, the fact that Vodafone uses the more usual mobile phone frequency may be a help.

Download Sakis3G

Creating a Data Set Containing Confidence Intervals Using PROC UNIVARIATE

While you could generate data sets containing means and confidence intervals using PROC SUMMARY or PROC MEANS, curiosity and the need to verify a program using a different technique were what drove me to consider using PROC UNIVARIATE for the task. For the record, the PROC SUMMARY code is below and the only difference between it and MEANS is that it doesn't produce output by default, something that's not needed in this case anyway. Quite why there are two SAS procedures doing the same thing is beyond me, though I do wonder if the NOPRINT option was a later addition than these two procedures. The LCLM and UCLM keywords are what triggers the calculation of confidence limits and the ALPHA option controls the confidence interval used; 0.05 specifies a 95% interval, 0.1 a 90% one and so on.

proc summary data=sashelp.class mean lclm uclm alpha=0.05;
    var age;
    output out=sasuser.lims mean=mean lclm=lclm uclm=uclm;
run;

Given that I have had PROC UNIVARIATE producing statistics that MEANS/SUMMARY didn't in previous versions of SAS (I believe that it was standard deviation that was absent from MEANS/SUMMARY), I might have expected the calculation and export of confidence limits to a data set to be straightforward. Sadly, it's not a case of simply adding LCLM and UCLM keywords in the OUTPUT statement for the procedure, and ODS OUTPUT is needed to create the data set instead. An ODS SELECT statement is needed to pick out the BasicIntervals output object (UNIVARIATE creates quite a few, it seems) that is created through specification of the CIBASIC and ALPHA (performs the same role as it does for PROC MEANS/SUMMARY) options on the PROC UNIVARIATE statement. The reason for the ODS LISTING and ODS RTF statements below is to stop output being sent to the output window in a standard SAS session. For some reason, it appears that you need the sending of output to one of the LISTING, HTML or RTF destinations or there will be no data in the data set; I met up with the same behaviour when using ODS PS, an ODS PRINTER destination. The data set will contain statistics for mean, standard deviation and variance, so that's why there is a WHERE clause on the ODS OUTPUT statement.

ods listing close;
ods rtf body="c:\temp\uni_eg.doc";
ods select BasicIntervals;
ods output BasicIntervals=sasuser.stats(where=(lowcase(parameter)="mean") );

proc univariate cibasic alpha=0.05 data=sashelp.class;
    var age;
run;

ods output close;
ods rtf close;
ods listing;