Erik on Software

New Book Review: "R Graphics Cookbook"

New book review for  R Graphics Cookbook, by Winston Chang, O'Reilly, 2012, reposted here:

This book is the third that I have recently used to get up to speed on the R language and environment. The other two texts include "R in a Nutshell" and "R in Action" (see my review). The main catalysts behind my decision to purchase another book on R was my need to get up to speed with using the language to create graphs, and that not only are plotting functions that come with base R not unified behind a common interface and set of options, there exist limitations with base R plotting functions. Of course, there are other plotting functions across the over 2500 packages that have become available to the community, but the ggplot2 package that is the focus of this book is well regarded and grown in use to become one of the most popular R packages since its release in 2005.

What Chang presents in this book is extremely practical. My recent pro bono work to move a client away from Microsoft Excel to this powerful open source platform and industry standard used for both small and big data analytics is partially testament to the usefulness of this book. While I have needed to peruse R package documentation as part of this work, it is not a stretch to say that a majority of what I needed was contained in this book, either as starting points or complete examples. The explanations are very well written and organized, and the fact that all of the pertinent graphs are in color was very helpful when it came time to understanding how ggplot2 can be used for tasks such as plotting multiple lines in one plot, and the data setup that is necessary to perform these tasks, which is a bit different than base R plotting functions, but worth the effort to use since ggplot2 employs universal usage patterns.

While "R in Action" might be better at easing the reader into the R language and environment, this book starts with enough R basics in its first two chapters, such as installing packages and loading data, that most will find it sufficient for getting their feet wet, and the author's introduction to ggplot2 in the appendix combined with Chapter 15 (Getting Your Data into Shape) are not only well done, but very succinct for busy professionals. After discussing bar graphs, line graphs, scatter plots, and summarized data distributions, the author presents annotations, axes, legends, and controlling the overall appearance of graphs, followed by discussions on facets, miscellaneous graphs, and outputting for presentation. If you are new to ggplot2, you will probably need to touch a majority of these chapters to some degree in order to get up to speed, but information is easy to find. Very well recommended.

New Book Review: "Seven Databases in Seven Weeks"

New book review for  Seven Databases in Seven Weeks: A Guide to Modern Databases and the NoSQL Movement, by Eric Redmond and Jim Wilson, Pragmatic Bookshelf, 2012, reposted here:

Over the past couple years, I have read considerably about non-traditional database products, whether they be categorized as NoSQL or NewSQL, especially the Hadoop ecosystem (see my reviews on "HBase: The Definitive Guide" and "Hadoop in Action"), but I only just recently completed a reading of this book after pre-ordering it over a year ago. I share the sentiment of other reviewers to some extent, in the sense that even though the authors call the content that they offer here a "crash course workshop" written for "experienced developers", the discussions of each database product vary in terms of the detail and pace at which they are presented. That said, this book does offer a look at the modern database landscape from the perspective of a developer, and presents material on each database product to an extent which prompts the reader to look to other resources for additional detail, a practice to which I have grown accustomed as a consultant, so this aspect of the book is not a negative thing in itself, just something of which readers need to be aware in the case they are not accustomed to this style of presentation.

By this point, there are enough reviewers who have discussed the fact that Redmond and Wilson explore seven open source database products in this book: Redis, Neo4J, CouchDB, MongoDB, HBase, PostgreSQL, and Riak. Since there are literally hundreds of open source database products, it helps to understand the fact that one of the reasons these seven database products was chosen was because they span several genres of database that were designed to solve problems presented by real use cases. PostgreSQL is the one relational database discussed. Riak and Redis are key-value stores, HBase is a column-oriented database, MongoDB and CouchDB are document-oriented databases, and Neo4J is a graph database. Since I have already gained considerable exposure to the Hadoop ecosystem, I concentrated on the six chapters not covering HBase, and in reading the HBase material I can tell you that it really just scratches the service of the product, so this served as a personal reminder of what the authors state multiple times throughout what they have to share here: this is introductory material.

Coverage of each database product follows a similar pattern over hypothetical three-day periods of time. If you are interested in reading this book, do not be intimidated by how the material is laid out according to the calendar. Each set of three days is really just three steps of progression, diving deeper with each step. The only exception to this pattern is coverage of Redis, the last database product covered. While technically the third step of the Redis discussion involves Redis, what it really provides is introductory material on polygot persistence, which involves database products working together. In the example that the authors present, CouchDB is the system of record, Neo4J handles data relationships, and Redis helps with data population and caching. The authors even present a good sidebar on why use of nonblocking code is such an important method when dealing with databases. The wrap-up that follows each three-day time period outlines the the strengths and weaknesses of each database product, and a wrap-up chapter at the end of the book outlines the strengths and weakness of each database genre, followed by an appendix that provides informational tables that compares each of the database products from several different angles.

While HBase is still the database product that attracts the data architecture aspects of my consulting career the most, of the seven database products covered PostgreSQL is the one that I have actually started using, due to practical reasons, but I am also increasingly interested in Neo4J, a graph database product providing full ACID compliant transactions to which I was first exposed at SpringOne a couple years ago. It is interesting that although this book was reasonably targeted at an audience consisting of "experienced developers", it is not a stretch to say that many developers naively consider data availability a given on their project assignments, sometimes because they do not want to deal with the data, and sometimes because they think the data is the easy part. Books like this which help bridge the gulf that often exists between those who seem to think that Java or some other language is all that matters in the enterprise, and those who consider the viability of only one database product, serve a great need, and do not fall into the set of O'Reilly texts that have strayed off course in recent years.

New Book Review: "The End of Competitive Advantage"

New book review for  The End of Competitive Advantage: How to Keep Your Strategy Moving as Fast as Your Business, by Rita Gunther McGrath, Harvard Business Review Press, 2013, reposted here:

While the term "competitive advantage" can be defined in more than one way, it can be argued that sustainable competitive advantage over rivals (i.e. holding on to market positioning relative to other industry players) is really a chief business goal when following such a strategy. Authors A. G. Lafley and Roger L. Martin in their recent "Playing to Win: How Strategy Really Works" (see my review) show from their experience that "no strategy lasts forever" and that "strategies need continual improvement and updating", but Rita Gunther McGrath demonstrates the need for firms to take these steps further, resulting in the likelihood of considerably more movement over time.

The author explains that there have been two foundational assumptions taken as gospel in the past: (1) "industry matters most", and (2) "once achieved, advantages are sustainable." While advantages can continue to be sustained in some industry sectors, these scenarios are becoming increasingly less frequent, and the author's research in this space demonstrates that "stability, not change, is the state that is most dangerous in highly dynamic competitive environments", and that "one of the biggest changes we need to make in our assumptions is that within-industry competition is the most significant competitive threat."

McGrath argues that firms need to increasingly compete with waves of temporary or transient competitive advantage rather than sustainable competitive advantage. In her presentation of the five phases (launch, ramp up, exploit, reconfigure, and disengage) that exist in each such wave, she stresses the fact that although exploitation of a transient advantage is advantageous for a period of time, excessive build-up of assets and people should be prevented as much as possible so that barriers to moving on to the next advantage are minimized.

In Chapter 2 ("Continuous Reconfiguration: Achieving Balance between Stability and Agility"), the author comments that "a pattern to look for in organizations that have mastered transient-advantage environments is the continual freeing up of resources from old advantages in order to fund the development of new ones", and the ten growth outliers her research team identified from nearly five thousand over the 1999 to 2009 time period demonstrate this pattern, which corresponds to equal emphasis on all phases of the wave just discussed, rather than exploitation alone.

Apart from the introductory chapter, Chapter 4 ("Using Resource Allocation to Promote Deftness") is probably the chapter I appreciated most. One segment, entitled "The Resources as Hostage Problem" is especially relevant to her presentation. The author comments that "in a traditional company, people who had lots of assets and staff reporting to them were the important people in the company", but that this "bigger-is-better mind-set is deadly in an environment in which advantages come and go. If people feel their authority, power base, and other rewards will be diminished if they move assets or people out of an existing advantage, they will fight tooth and nail to preserve the status quo."

And as a consultant, I find it interesting that the segment entitled "The Concept of Asset Debt" uses the term "technology debt" in conjunction with the need for firms to keep technology assets in a fit state in order to support competitiveness, and that continual investment and a willingness to leave older assets behind is a requirement for such a state. Usage of this term is a very relevant expansion of the much older term of which I am familiar, "technical debt", revisited at a practical level a few years ago by one of the contributors to "97 Things Every Software Architect Should Know" (see my review).

"So Why the concern over making changes properly now versus later? It's because there's a hidden cost to making these quick and dirty fixes. For financial debts the hidden cost is called 'interest', and most anyone with a credit card knows how expensive just paying the interest on a debt can be. For technical debt, interest takes the form of instability in the system, and increased maintenance costs due to the hacked-in changes and lack of proper design, documentation, and/or tests. And, like financial interest, regular payments must be made until the original debt is repaid."

While the term "technical debt" is used differently in the context of what the author shares in her discussion here, there also exist similarities in the sense that both exact penalties in the form of interest. For firms which still strive to sustain competitive advantage, such interest might prove to be so costly as to become too unwieldy for survival, missing the ability to compete with waves of transient competitive advantage in the interim. This book adds to the strategy bookshelf in a way that helps bridge some of the gaps that have existed in recent years, and makes these bridges relevant by presenting original research.

Rave Run: Chesapeake & Ohio (C & O) Canal Towpath and Potomac River Waterfront (Georgetown)

Why a post on running within a blog that concentrates on business and technology? My first post in this series explained that one habit that I picked up on the road as a consultant over the years is always inquiring about local running paths while visiting unfamiliar locales for the first time. And I find running a pleasurable way to explore new places. Other posts have commented on how running has been a gift to me from an early age by helping me focus and providing stress relief. So in the spirit of a regular spread in Runner's World magazine called Rave Runs, I began a series of posts here to share interesting routes with other runners.

This past March, I was fortunate to visit Washington, DC for the first time. Unlike some other recent travels, such as to a Detroit area client this past month, I had time to check out the area for running opportunities ahead of time, and the Lonely Planet Washington DC City Guide made me aware of the Chesapeake & Ohio (C & O) Canal Towpath and Potomac River waterfront, which includes the recently expanded Georgetown Waterfront Park, a spot that over the course of my weeklong visit became one of my favorite landmarks for this course, which varied a bit but started from my stay at Avenue Suites Georgetown just east of Rock Creek.

The start of this course starts rather unassumingly on Pennsylvania Avenue NW, and can either continue west on M Street NW through the heart of the Georgetown shopping district, or south along the ramp for Rock Creek and Potomac Parkway NW. This latter variation is what I discuss here. The first morning I ventured out for a run, I headed through the shopping district. Although I continued my habit of running early, which not only misses all the shoppers and most other runners, I soon unsurprisingly found that I would much rather hit the trails at the beginning of my runs than the uneven historic cobblestone streets running through Georgetown.

While I may be accustomed to my daily runs on the crushed limestone of the Illinois Prairie Path and Great Western Trail in the Chicago area, however, I admit that the varied running surfaces on this course were interesting. The modern cobblestone paths at the entrance to this area, which includes a national historic park, are the first options that present themselves along this course, and provide a nice diversion when touring the waterfalls along the canal for the first time, but these paths are narrow, on uneven ground, and intersect with a number of streets continuing west. If you can plan accordingly, walking along these paths at the end of your runs is optimal because of the meditative water features.

While running surfaces vary, the width of each of the connecting trails is fairly consistently narrow. This narrowness can pose issues to the runner when considering the historic cobblestone streets, and during transitions of one type of trail to another, but once on the canal towpath, provided one is not traversing them during the day, these issues are minimized. In my opinion, the towpath that runs on either side of the canal is so narrow that it can understandably feel as though it was made for the individual, especially when lost in thought midway through a run. The only drawback here is that during the course of my runs these thoughts were only a stone throw away from falling into the canal, which might not seem possible given that the photos here were taken later in my stay as a retraced my route during daylight.

Georgetown Waterfront Park provides a short rendezvous with a boardwalk along the Potomac River, which provides a beautiful view of the Arlington, Virginia skyline before sunrise, and as you can see here, a chance to see rowing teams traversing the waters, at least after sunrise. The grounds of the park are pleasant, although my visit was during the Cherry Blossom Festival season of the year, so much of the vegitation had not yet surfaced from the colder months. Some runners may want to take note that the connection to the waterfront from the towpath is made via a staircase and underneath Whitehurst Freeway NW, which provides some lighting at night, but might be a bit disconcerting.

A series of stairways mentioned previously runs on either side of the canal towpath and makes the connection back to the Georgetown shopping district along and north of M Street NW. The last photo below is included here because I want to emphasize that not only are their varied running surfaces of interest to the runner, but varied inclines as well. While the waterfront and canal towpath are even running surfaces, regardless of which routes taken the runner will need to eventually take paths that are uneven, and in the case of the historic cobblestone streets at the top of the set of stairs pictured, a fairly steep incline. But most runners will likely enjoy this aspect of the course, and as a Chicago area native I can say that I most certainly did as well.

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Rave Run: Buffalo Bayou (Houston, Texas)

Rave Run: Great Western Trail (Lombard, Illinois)

Rave Run: Ridges Road in Door County (Baileys Harbor, Wisconsin)