Month: May 2008

Weekend Cat Blogging: The Heat

The temperature hit 97F (35C) yesterday, which is exceptionally hot for San Francisco. Felt great to me, but it's a bit too much for the ketzela.

Here we see Luna trying to beat the heat resting under her new favorite table:

Even in the heat, she seems to have a sense of style. And fun. Note the cardboard furniture box to the left. Luna has always been fond of cardboard boxes, and this new one is no exception. Lots of fun for the teeth and claws, especially when you don't have to move far to reach it.

Like we said, this has been an exceptionally warm few days. It is famously cold and foggy during the summer months (June, July and August), though less so in our neighborhood. But it has been delightful to spend warm evenings out on the patio; and that “incipient warmth” in the morning, where the air still has a chill but one can feel it disappearing quickly. And with the energy of the city all around us…

It's never too hot for Weekend Cat Blogging, which is going on at Chey's Place.

The Bad Kitty Cats Festival of Chaos is returning home to the Bad Kitty Cats Journal this weekend.

The Carnival of Cats will be going up this Sunday at Artsy Catsy

And of course the Friday Ark is at the modulator.

Prime-counting function revisited

A couple of weeks ago we posted an article on “Calculus for Cats” and the Prime Number Theorem, which featured the, the prime-counting function π(x):

Basically, this function counts the number of primes less than or equal to a particular number. For example π(20) would be all the prime numbers less than 20: 2, 3, 5, 7, 11, 13, 17 and 19. So π(20) = 8.

So to calculate π(1000) would one have to literally count all the prime numbers less than 1000, including figuring out which numbers are prime? And what about π(1000000)? Unfortunately, the answer is yes.

Unfortunately, the answer is no, as Victor points out in the comments. Or more specifically, Victor's cat Blue Chip says “Neow!” I think is the point where one is supposed to say “my bad.” Victor is in fact V. S. Miller who co-authored the paper “Computing pi(x): The Meissel-Lehmer Method”.

The oldest method for computing π(x) is to use the sieve of Eratosthenes, which is literally counting all the primes below x. More efficient methods have existed for quite a while, notably astronomer E. D. F. Meissel found a method in the 1870s that he used to compute π(100,000,000) as 5,761,455; and π(1,000,000,000), though his result was found to be slightly off (too small by 56). It should be noted that Meissel carried out his calculations without the aid of a digital computer. D.H. Lemher extended and simplified Meissel's method in the context of modern computers, and calculated π(1010).

Miller and his co-authors present new algorithms that refine the Meissel-Lehmer method, including new sieving techniques and optimizations for parallel computing. Those interested in the technique are encouraged to read the paper. The “Extended Meiseel-Lehmer” technique is used to compute π(1016) as 279,238,341,033,925.

They also include an interesting chart comparing large values of π(x) and Li (x), the offset logarithmic integral that we presented in our article. Recall that Li(x) is an upper bound on the value of π(x). And for 1016, the difference between Li(x) and π(x) is 3,214,632. Only off by three million, which isn't too bad…

This post was included in Carnival of Mathematics #33 at Walking Randomly.

Primary Highways: West Virginia

Well, this is probably the most difficult state we've had to write about since beginning this series. Even harder than Indiana last week.

I did travel through West Virginia a couple of times on family road trips in my youth. We definitely passed through the panhandle on I-81, an area that probably now identifies more with the DC and Baltimore metropolitan area than with the rest of the state. I do recall signs welcoming us to “Wild, Wonderful West Virginia.”

The capital and largest city, Charleston, has a population smaller than my former hometown, Santa Cruz. The state is synonymous with coal mining; and with some rather harsh stereotypes that have surfaced in the last weeks, especially with the demographic issues in the current campaign. We at CatSynth would prefer to consider the state's striking landscape and beauty as suggested by its iconic New River Gorge Bridge:

The New River Gorge Bridge carries U.S. Highway 19 over the New River. At a height of 876 feet (267 m), it is the highest vehicular bridge in the Americas, and the second highest in the world. This section of Highway 19 forms a rather spectacular bypass of Charleston and connects two of the states major highways, I-77 and I-79.

Situated in the Appalachian region, West Virginia is full of mountains and canyons, but altogether different from those one finds in the western U.S. The landscape isn't quite as “stark,” and its features are much older than the Sierra Nevada or the Rocky Mountains or the canyons of the southwest. Indeed, the Appalachians are one of the oldest mountain ranges that can still be considered “mountains.”

There is also Spruce Knob, the highest point in the state. And this cable-stayed bridge over the Ohio River introduces a more “industrial Midwestern” area altogether different from the New River Gorge.

Quite a geographical diversity for such a small state. And perhaps appropriate given its history as a border region and breakaway state during the American Civil War. West Virginia pulled off the trick of seceding from a secessionist state, Virginia. It was admitted in 1863 under somewhat controversial circumstances, but has managed to forge an identity of its own.

Midnight Monday: Gallery Cat

No, this is not Luna. This is the unofficial “gallery cat” at the Luggage Store Gallery.
He came over to check out my gear as I loaded in on Thursday.

It's always a good sign to see a cat, especially a black cat, before playing.

Check out more Midnight Monday on House Panthers.

Fun with stats: 100th Anniversary of Mother's Day

From the Associated Press:

55 percent of mothers are between the ages of 15 and 44.

81 percent of women between the ages of 40 and 44 are mothers. In 1976, 90 percent of women in that age group were mothers.

94.1 births per 1,000 is the number of births in Utah in 2006, the nation's highest. Vermont was the lowest with 52.2. West Virginia's was 58.3

10.4 million single mothers live with children younger than 18, up from 3.4 million in 1970.

83 percent of mothers who went back to work within a year of their child's birth returned to the same employer.

5.6 million is the number of stay-at-home moms in 2006.

Weekend Cat Blogging: A Busy Week

Every week is a busy week here at CatSynth, but this past week has been exceptionally so. Of course, there was the show and all the preparations. Work was more intense than usual as well. Also a fun this week, good food and drink and friends; and a volunteer activity. And lest we forget, the Bad Kitty Cats Festival of Chaos last weekend.

But in the midst of all of that, Luna makes sure to get the attention she deserves:

As the studio takes shape, old activities return, like pawing at my chair for attention, and resting in the beanbag.

And now, we rest:

Some very sad news from our friends Megan and the Bad Kitty Cats. Braum Kitty and Rimbaud have passed away in tragic circumstances, and are dearly missed by their family. There is joy as well, with the new kittens the “Three Blind Mice.” And they will be hosting the Carnival of the Cats this weekend.

The Cat Blogosphere has this wonderful tribute to mothers, feline and humans.

More food and friends. Weekend Cat Blogging #153 is being hosted by sher and Laura and Pumpkin. Laura is growing and looking more like Luna.

The Bad Kitty Cats Festival of Chaos is being hosted by Sleeping Mommy. And of course the Friday Ark #190 is at the modulator.

Preparing for tomorrow's performance

Well, the first big solo show since moving to the city is nearly upon us. And it's a big one, at least in terms of the setup and preparation. Indeed, this is the largest and most complex setup I have used for a live show in quite a while, with both Mac and PC laptops, the tablet, MIDI keyboard, the Evolver synth, and the Proteus 2000 module. And of course the rather byzantine wiring and signal routing to keep it all together.

In the photo, one can see not only the equipment, but a couple of the acoustic instruments I will be playing including the ektar and the gopichand.

Why such a complex setup? Well, I wanted to a variety of pieces for this performance, combining both the newer simplified performances (such as those I did last year on tour with Polly Moller and Company), with some of the older more complex works. I also wanted to play the tablet, which I haven't done in a while, and it only runs on the older PC laptop; and include a couple of pieces from the CD, including Chimera and a variation on Xi. I was a little bit concerned about pulling out the old laptop for this performance, but after some effort it's running decently, and it's great to be able to blend elements from my older performances with the more recent ones. And in truth some of the older pieces are more fun to play, such as Chimera on the tablet, and the patch that responds to live drumming (officially called “drummer boy”).

Luna has of course had to make her presence felt during the rehearsals, as you can see here.

After a shaky start, the program has come together quite nicely in the last few days, and I am now looking forward to performing tomorrow.

For those interested, the time and location is:

Thursday, May 8, 8PM
Luggage Store Gallery
1007 Market St.
@ 6th Street
San Francisco, California

More details can be found here.