Scherzi

True and False in the C Programming Language

2012-01-11T09:41:00.004-05:00

I know, C is dead, right? Not quite. While C has been supplanted in many industries by C++, C#, and other object-oriented languages, much of the automotive industry still relies on plain vanilla C - MISRA C, to be specific. I overheard the following question today: "should TRUE be set to !FALSE or should it be set to 1 - which is more MISRA compliant?" I don't know which is more MISRA compliant (off the top of my head), but I'd like to offer an alternative that, to my thinking, is more type-safe and avoids clashes with the macro definitions provided with many compilers.

Since C does not have native support for a Boolean type, it is common to #define TRUE and FALSE:

#define FALSE 0

#define TRUE !FALSE

FALSE is always zero and true may be any non-zero integer, so it is safest to let the pre-compiler decide what !FALSE means. This is portable but not type-safe; TRUE and FALSE may be compared to a result of any type (leaving the type conversion to the compiler). I like to use a typedef'd enumeration, instead:

typedef enum {eFALSE = 0; eTRUE;} BOOL_t;

Since this is "user defined", it is incompatible with the return type of standard library functions, so they must either be handled in the typical manner or with explicit casts.

Thinking about how to define and use boolean types in C reveals an important lesson about the "safe" use of C. That is: Avoid comparisons to TRUE (or eTRUE or whatever). Since zero will always be "false", comparisons with FALSE will always work.

Fitting a Round Peg into a Square Hole

2012-01-03T10:08:00.003-05:00

I received an iPod nano for Christmas. It's just what I wanted but I was not looking forward to moving the 400+ albums I had in Windows Media Player - complete with album art - into iTunes. My anxiety was warranted: the result was a disaster. So, I took the opportunity to completely re-rip my entire CD library into iTunes. I chose to keep working with the mp3 format but bumped up the resolution from 128 kbps to 192 kbps. I must say that iTunes seems to do a slightly better job of finding album art than WMP, though I still found many albums for which I had to manually paste an image (either found on the web or scanned from the original).

Resurrection?

2010-02-10T11:04:00.003-05:00

Wow - over two years since my last post here ... wondering if I really have anything to say. Maybe I'm just a little paranoid about putting myself too "out there" on the Web, afraid to voice a disagreeable opinion or to be judged in an unfavorable light. I've witnessed too many "flame wars" ignited and fueled by thoughtless comments and want no part of that childish game. So it's safer to remain a lurker in the shadows. But - what the hell? - nothing ventured, nothing gained.

Random thoughts for today:

I tried Twitter for a short time. I can see its appeal but I had little to say and became overwhelmed with the influx of short messages from those I was following. Tried TweetDeck to get some sort of grip on the volume but the whole thing just became a time vacuum. So I deleted my account and I haven't missed out on anything important yet.

I do have a presence on LinkedIn. My network isn't that big but the service does keep me connected to my career industry.

I uploaded a bunch of stuff to my photostream on flickr - mostly recent art work from my participation on wetcanvas.com.

The Inter-Urban Industrial has been disassembled and moved twice in the last two years. I need to get some new pictures up on Flickr.

Railroad Update

2007-01-08T14:02:00.000-05:00

The pictures are here!

The current state of my small N-gauge empire can be seen here.

House of Leaves

2006-02-07T22:57:00.000-05:00

I've gotten tied up in reading House of Leaves by Mark Z. Danielewski. What an incredible work of literature! I'm about 3/4 of the way through and I'm thinking I'll have to re-read it immediately to get the full effect; there are so many mysteries.

Anyway, the vocabulary in HoL has been challenging me. Here's a few new words I've learned:

sabin
aphonia
scarification
tenebrific
tessellated
celerity
phillumenist
prolix
exegesis

Go loook them up if you don't already know their meanings.

Inter-Urban Industrial Update

2006-01-04T16:17:00.000-05:00

The IUI has been downsized to something a little more manageable for my first foray into model railroading since I was a child. My little industrial empire now fits on a two foot by four foot table top. Here's the new plan:

I've left some expansion room to the right side, where the interchange track comes in. Where I intend to place the layout in my basement, I have another seven feet of shelf space about a foot wide. I've elevated the back side about 3/4" from the front to give a little interest to the terrain but the setting is essentially urban. The yard consists of 3 sorting tracks and a RIP track, with an engine terminal off the runaround. The right side of the loop also serves as the switching lead. The short siding crossing the yard lead serves a small freight station.

I've got the base built and a layer of foam on top of that. I've test fitted the track and will be ready to lay roadbed as soon as I purchase or manufacture the 3% grade inclines on get to the back industrial area.

Photos of progess to follow soon.

The Whole-Tone Scale and Augmented Chords

2005-12-04T13:36:00.000-05:00

In my study of jazz improvisation pedagogy, I've noticed a relative scarcity of instruction related to the whole-tone scale and the augmented chord that derives from it. There is quite a bit of information on the lydian-augmented scale, which is the 3rd mode of the ascending melodic minor scale, but even here there is a lack instruction on how to apply the scale in context. It seems to me that most of the literature focusing on scales does not go far enough in explaining the application of such scales in the context of the entire structure of real songs. In other words, it's easy enough to see that particular notes of a scale (i.e. the intervalic distances from the tonic) correspond with a particular chord (especially its altered extensions) but what are the possible functions of a scale or chord related to the surrounding changes in a song?

The augmented scale has intrigued me since I first learned about it in junior high school. I was taking saxophone lessons from a guy that got me interested in jazz improvisation. I had learned to write and play all of the major and minor scales (both melodic and harmonic) from memory and I wondered what other scales existed that I might have to memorize, hoping there were none. That's when my instructor embarked on several lessons in scale and chord construction and the limitless possibilities of sound using only the 12 tones of our Western chromatic scale. The first thing he showed me was that scales could have fewer or more tones than 7 (the number of tones in the majors and minors) and proceded to write out the formula for constructing a whole-tone scale : 1-1-1-1-1-1 (he always wrote scale formulas in terms of the intervals between successive notes, so a major scale would be written 1-1-1/2- 1-1-1-1/2). When he asked me to play a whole-tone scale starting on C, I was blown away by how accustomed I had become to diatonicity. My fingers had a hard time finding F# and G#. The B-flat (as I thought of it, instead of A#) was not as foriegn because I was used to playing the mixolydian modes, with their flatted sevenths. What really intrigued me about the whole-tone scale was that there are really only two of them (and only 4 augmented chords).

I've been trying to figure out how to use the whole-tone scale and the augmented chord in my improvisation ever since my first revelation. One of the first things I discovered is that the augmented 5th naturally resolves upward to become the major 3rd of the next chord. So a C+ chord naturally moves to F major. In other words, an augmented chord functions like V7 leanding to I. This is useful for the end of a song that ends on the V because V+ will naturally lead to Imaj, and this is can be heard almost as a signature in many older R&B and do-wap songs. It's fun to put a V+7 at the end of a blues progression. The disonance of the whole-tone scale can be suspended for a greater length of time in this situation because the tension is usually the greatest here and the listener expects a resolution on the downbeat of the next chorus. A III-VI-II-V-I turnaround offers an opportunity for whole-tone utilization because the III, VI, and II are really just substitutes for the V and the whole sequence functions as single dominant leading to the tonic. Playing a line on the whole-tone scale I+ just before the change to IV can add a sense of playing "outside" or ""sideslipping" but this opportunity comes and goes quickly as the tension and resolution of a I-IV near the beginning of the chorus does not have the urgency of a V-I progression. I've been trying to think of a way to keep the dissonant energy of a whole-tone line going from the final V of a blues chorus, through the I at the start of a new chorus, all the way to the IV in the 5th bar but I've not been successful in pulling this off (yet).

I've had quite a bit of success playing whole-tone patterns in modal playing, especially "one-chord" tunes where playing outside is almost a requirement to break the monotony. In a recent extended solo on Chain of Fools (known euphemistically by our band as Chain of Chord, or sometimes just Chord), which is in C minor, I managed to build the tension up through the use of chromaticism and a neopolitan minor scale to 8 bars of whole tone figures on E-flat. This had the effect of adding a flatted 9th to an ascending C melodic minor while omitting the root. A few obtuse counter-figures from the rhythm section really polished off the effect.

Palindromes

2005-11-22T21:55:00.000-05:00

You're about to get a glimpse of the way the Mind of Kevin Bowman works. This is also an example of why people who have ADD tendencies should stay away from the internet.

For reasons I can't remember, I was talking with a work mate about strange audio processesing algorithms when I recalled seeing a farcical processing device on the internet that named all of the controls and such with palindromes. A quick search found the device in question to be the palindrometer (found here). Then I remembered hearing a satirical skit on NPR (my buddy Dave calls it National Proletariat Radio) that was an interview with a guy named Bob, who spoke entirely in palindromes. Of couse, this instigated a thourough search of the 'net for a transcript of that dialog. I did not find what I was looking for but did find several sites dedicated to palindromes and one site led me to another on which I discovered an intersting (to me) mathematical problem involving numerical palindromes (numbers like 12321).

So now I'm completely intrigued by this mathematical problem, which you can read about here. I started thinking about a related subject: what does it mean to "reverse a number"? And I discovered a couple of interesting things:
1) The absolute value of the difference of a number and it's reverse is a number evenly divisible by nine. This was really no surprise once I remembered the old accounting trick related to transposed digits (if the error is a multiple of 9, you've probably made a transposition error).
2) The result of dividing the difference mentioned above by 9 is often a palindrome! This was true for all of the numbers I first experimented with. My first experiments were with sequencial digits, like 123, 456, 987654, etc. I even tried 196 (196 - 691 / 9 = 55). However, I was able to find numbers that, when subtracted from thier reverse and divided by 9, did not result in a palindrome (72157 - 75127 / 9 = 330).
3) At least for some numbers, the process of "reverse and subtract" (and taking the absolute value) results in a palindrome. The number 196 "solves" in this case:
196 - 691 = 495
495 - 594 = 99

Subtraction is nothing more than adding with negative numbers. Perhaps this will open the door to generalizing the "reverse and add" process and help gain some understanding with the 196 problem. Or perhaps I've just found another way to waste a bunch of time.

Model Railroad Theme

2005-11-20T22:16:00.000-05:00

I've devised a name for my model railroad empire (such as it is). The theme is urban industrial and the name of the branch is the Inter-Urban Industrial Line. Pretty generic, I know. But since this is a freelanced layout (not representing any particular "real" place), I thought I could exercise a little artistic license. The Inter-Urban Industrial color scheme is orange, black, and white. The following two pictures are the logo on black field and on orange field, respectively:

When applied to locomotives, the horizontal stripes exend the length of the cab.

The era I am modeling is the early '60s. Steam has been completely phased out so the loco' fleet is entirely diesel or diesel-electric. A future expansion will model an interchange with a Grand Trunk double-track main, so some loco's from other railroads may operate on the IUI.

Here's the complete track plan:
The 2' X 4' section in yellow is the future addition. The darker colored track near the top is hidden from view by buildings, backdrop, whatever. Structure placement and the layout of the downtown area on the right side is preliminary.

I still have to nail down the industries on the IUI. Some ideas include a pertroleum refinery, a couple of freight stations, a piano factory, a furniture factory, a brewery and/or bottling plant, a lumber yard, and distributers (in town) of fruit and bottled goods.

Miscellany

2005-11-17T10:39:00.000-05:00

Today, I'm lamenting the fact that this blog has not been very interesting (totally boring is more like it). Creative juices have been flowing but not the kind that produce text of any sort.

I've spent quite a bit of time in the last six months thinking about and designing a modest model railroad layout. Construction will begin soon and I hope to have track laid and trains running before the New Year. My original plan occupied the entiure 19 feet of one wall in my finished basement. The final plan has been scaled back to 2' X 8' with accomodations for another 2' X 4' extention on an 'L'.

I've discovered a new addiction: Sudoku. It's a paper-and-pencil number placement game made popular by Nikoli publishing in Japan (though the game's roots are ancient). I obtained a book of 320 games, fairly evenly divided between easy, medium, hard, and extra hard puzzles. I can solve the easy puzzles in about 20 minutes. I've heard that expert solvers can complete a hard puzzle in about 10 minutes. I'll keep practicing.

Rhumba

2005-10-04T11:37:00.000-04:00

Samba

2005-10-04T11:35:00.000-04:00

Upcoming Events

2005-09-19T10:55:00.000-04:00

Jam dates at Baker's Keyboard Lounge:

Oct. 5
Oct. 19
Nov. 2

B-Side Blues Project at Corradi's Sports Bar on October 29. This will probably be our last gig of the year at Corradi's.

B-Side Is Back

2005-07-07T17:11:00.000-04:00

The B-Side Blues Project, a six-piece blues band, will be playing Saturday, July9 at Corradi's Sports Bar. Corradi's is located 1090 Rochester Rd., Troy, MI -- that's between 14 Mile and Maple (a.k.a. 15 Mile). We'll be starting around 9pm and playing until 1am. Come and join us for this premier reunion engagement. We'll be playing a little more regulary again but we'd really love to see you this weekend.

B-Side Blues Project is:
Kim Lang - vocals
John Giordano - lead guitar
Kevin Bowman - saxophones
Dave Sobolewski - keyboards
Skip Barnes - bass
Dan Ragnoni - drums

My Other Little Girl

2005-06-09T09:01:00.000-04:00

This is Rhumba. She likes sitting with her paws resting on something. In this picture she's resting on the railing at the top of the stairway. She also has a favorite chair in which she sits with her paws over the arm rest.

First Mobile Pic Post

2005-06-03T10:37:00.000-04:00

It's "daddy's liitle girl" Samba

It's Here

2005-06-03T10:32:00.000-04:00

I got the Treo a week ago and I'm just now playing with the mobile blogging possibilities.

Coming Soon

2005-05-19T10:06:00.000-04:00

Verizon begins selling the Treo 650 smart phone to individuals on May 23 and I'm going to be in line to get one. PalmOne upgraded the camera to 1.3 pixels which seems to be a minimum for usable photos. Blogger offers a mobile blogging service so you can expect to see some snapshots here in the near future.

Two Become One

2005-05-19T09:52:00.000-04:00

I've merged my other blog, Omnisonus, into this one. I just didn't see much sense in maintaining two separate blogs with links to each other since I wasn't posting frequently to either one.

New PDA

2005-04-25T14:21:00.000-04:00

I got my eye on a new gadget: a Treo 650 Palm PDA/Phone. My current phone and my current PDA are both over five years old. It's about time to replace both of them. Why not kill two birds with one stone? Verizon (my cellular carrier) will be offering the Treo 650 beginning sometime next month. My only reservation is sacrificing analog service as a fallback. The Treo is digital only and digital converage in Michigan is not as extensive as the analog coverage. But I'm gambling that that will change in the next few years.

Moog

2005-04-20T09:49:00.000-04:00

I saw Moog at the Detroit Film Theater Monday night. The documentary was a little slower that I expected, mainly due to halting quality of Bob's presentation. I had also expected more demonstrations of the instruments he invented, though a complete solo by Keith Emerson was offered in it's entirety.

Robert Moog has some interesting insights on the nature of invention. His views are decidedly spiritual or meta-physical when he talks about the man-machine connection he experiences with electronic equipment and that musicians experience with their instruments. He states that this connection is really bidirectional: not only does the player control the instrument but the instrument, in some manner, retains memory of the player and thus exerts a force on the musician.

The name "sythesizer" is often presumed to be derived from the premise that the generated sounds are synthetic (and, somehow, not real). Bob debunks this notion, claiming that the name comes from the fact that the sound is sythesized, or combined, from various modular components. Indeed, he says, the sound produced is very real.

I was most impressed by the performance of a young Japanese musician playing a theramin. I've never heard that instrument played with such accuracy. The lyrical impression of a cello was expected but the intonation was impeccable. I would not have believed the demonstration of a stacatto walking bass line in the jazz idiom, complete with triplet "kicks", had I simply heard it without the visual.

Morning Drive

2005-04-19T09:49:00.000-04:00

Judy Adams really hit the sweet spot on her WDET program this morning. The lineup starting at 9:00 am was some pretty tasty jazz from Regina Carter, Jean Luc Ponty, and Ron Carter. It really made a long commute enjoyable.

Palm Disaster

2005-04-15T15:43:00.000-04:00

My aging Palm Pilot IIIxe recently got wiped clean. That can happen if the alkaline batteries aren't replaced shortly after they're completely drained. I'm very faithful about replacing the batteries and this is the first time since I started using a Palm (about five years ago) I've experienced a complete memory erasure.

The mysterious amnesic event occured on Saturday. I had just referenced the address book on Friday and noted that the battery meter indicated about 50% (is that half full or half empty?). Saturday, while driving my wife's car to a family event, I placed the Palm on the center console. When I later accessed the device to check my schedule, I thought it odd that the digitizer calibration screen was active. And after re-calibrating the touch screen, I discovered that everything was gone. Hard reset.

I suspect the culprit was an EMF (electro-magnetic field) strike. My wife's car is a Saab with the ignition switch in the center console, only centimeters away from where I placed the Palm. The vehicle's key is not a normal mechanical one but rather a plastic fob with RF-tag technology. It's quite possible that a sizeable EMF could be generated when the ignition switch "reads" the key's information. Some of my colleagues who work with key fobs concur.

I've recovered most of the data (addresses, appointments, notes) from a six-month-old backup but all of the 3rd party applications I used to have are lost. Since I first loaded those applications onto the Palm, I've restaged the computer I sync with and I forgot to save the PC copies of those applications. So I'm now on a quest for useful free applications.

One neat thing I found was a compact Bible (with a special reader) from Olive Tree Bible Software, Inc. (www.OliveTree.com). The entire King James Version consumes only 1.4M. Other versions are available, some free and some for sale. The reader features a word search (no need for concordance!) as well as the ability to store your own notes attached to verses. If you want to fill up memory, multiple bible versions can be loaded simultaneously and can even be viewed side-by-side (one over the other, actually) in a split screen mode.

Reading Review

2005-04-15T10:12:00.000-04:00

Currently Reading:

Manifold: Time by Stephen Baxter
Poetics of Music by Igor Stravinsky
The Gift of Change: Spiritual Guidance for a Radically New Life by Marianne Williamson

Moving Music

2005-02-25T09:48:00.000-05:00

During my morning drive to work, I listened to two powerfully emotional songs -- one by Bob Brookmeyer and his New Art Orchestra and the other by Maria Schnieder, a one-time student of Brookmeyer.

American Tragedy, performed on the 2002 album Waltzing With Zoe. The liner notes claim that this is not about the terrorist attack on the Twin Towers (it was recorded before that event) but about the Supreme Court decision in the 2000 Bush v. Gore election. It's a dark, moody, somber piece in a minor key that can almost make me cry with sadness.

Hang Gliding, on the album Allegresse, is a rhythmically ingenious invention depicting the flight of a pair of hang gliders. The alternating measures of 6/8 and 5/8 create a sense of excitement and a feeling of precarious balance on the verge of falling. A trumpet solo over extremely sparse accompaniment portrays the solitude of floating through the atmosphere. I always feel exhilarated when I hear this piece.

Jam Sessions

2005-02-21T09:46:00.000-05:00

Baker's Keyboard Lounge, at 20510 Livernois, in Detroit, is the oldest continuously running jazz club in the United States. A few years ago, it was listed as one of the top three jazz clubs in the U.S., the other two being in San Francisco and in New York. On Wednesday evenings, Baker's hosts an open jam night with a house trio of veteran jazz musicians led by Dr. Teddy Harris at the piano. For the past few months, Dr. Harris has been ill and the capable Kenneth Cox has filled in at the keys. Bassist Don Mayberry and Drummer George Davidson complete the trio. It is not uncommon to see nationally recognized musicians drop in on a Wednesday evening for a little impromptu fun. Recently, James Carter, Don Waldron, and Martha Reeves have graced the Baker's stage with their presence.

Every other Wednesday, I make the trip to Baker's with a horn or two and participate in the open jam session. The use of Fake books during the jam is frowned upon so I've been focusing on memorizing the most-requested standards in my practice sessions. The likes of On Green Dolphin Street, Autumn Leaves, Have You Met Miss Jones, There Will Never Be Another You, and Just Friends get called quite often at Baker's. Every time a tune is called that I don't know, I add it to my "to learn" list. Some nights, there are quite a few vocalists who want to sing a couple of tunes and these are usually easy enough to blow through a chorus or two whithout having to know the head. After having spent a few years honing my improvisation skills with Jamey Aebersold play-alongs, I thought I was ready to mix with the "big boys" at Baker's. I've been visiting the jam sessions for about nine months now and have gotten some favorable compliments on my sound and style from listeners and musicians alike.