voluntaryXchange

“Reverse Phone Book” for Algebra

I came across an interesting site called RIES. If you give it a number, it returns equations that approximate that number.

Weird, eh? Usually you have a tough equation, and you approximate a solution to it with a number.

For example, I input 42, and RIES outputs these equations that can be solved for x and which yield an answer close to 42:

• x+7=7^2, an exact solution
• 3x=5^3, approximation is accurate within 1%
• (x+5)^2=3*7, , approximation is accurate within 1%
• x^5=8^9, approximation is accurate within 1%
• 5(x+1)=6^3, approximation is accurate within 1%

An odd thing for someone who isn’t a mathematician: this is sort of like a reverse phone book for algebra.

Via I Love Charts via the details in the fabric via XKCD.

Technorati Tags: reverse,phone,book,algebra,ries

Cool Dog Photo

This came through e-mail with a set of similar photos of dogs chasing a tennis ball in the water:

I wonder who got the ball?

Hat tip to PA.

Technorati Tags: dog,water,tennis,ball

Google Tip: Image Search

Wow … this is such a cool tool … but it’s in need of a real use.

Here’s a (frivolous) example of what you can do with Google Image Search.

Suppose you see a picture you want on the internet, but it’s too small. Drag and drop that image onto Google Image Search and it will find better versions.

So, consider those thumbnails that pop up on the side of popular sites. Like this (100 x 75) one:

First, right click it, and save the image to your hard drive. Then open Google Images. What you see is what looks like a normal search bar, but when you drag the image over it, it will prompt you to drop the image.

Then Google goes and searches for similar images on the internet. In the case of this stock photo used to advertise work-at-home schemes, Google returns several hundred images, including this (550 x 368) one with about 30 times as much detail:

But, it’s not foolproof. A lot of it seems to be based on matching colors in various parts of the image. So this (110 x 80)  thumbnail downloaded from the same ad-filled sidebar:

yields no matches, but a number of suggested images that don’t match, like this:

The thing about this tool is … what on earth is its legitimate use? I’ve known about it for a few months, and I haven’t come up with one yet. I mean, you could do something like input a thumbnail of Renoir’s Dance at Bougival to try and find a wallpaper sized version (yes, this works).

N.B. Yes, I used the image of the pretty girl to get your attention. But, no, I’ve used this tool a few dozen times and it has never returned a photo that was pornographic. I have also submitted some photos that some would regard as pornographic, and it doesn’t return pornography to those either.

Technorati Tags: google,image,search,renoir

Everything You Ever Wanted to Know About a City

City-Data.com is kind of amazing. The volume of information collected in one place is stunning.

When you go to the site, you either enter a zip code, or choose a state and select from its list of cities. Note that you’ll get different information depending on which way you choose to proceed.

Be aware that there are a ton of ads at the top.

But, for my middle-of-nowhere zip code they were followed by 26 (portrait) screens of data. There were 25 somewhat different screens for my city.

The locations summarized are comprehensive too. I grew up in New York, which has incorporated villages inside incorporated towns. The village of 5,000 people I grew up in has a similar amount of data, as well as some overlapping data for its zip code, and data for the town which it is a part of.

Via bookofjoe.

Technorati Tags: city,data

Some Kind of First

My academic work didn’t get a journal citation this time, but I got a thank you.

Ten year ago, when I was the experienced “research guy” newly hired by a teaching school, I did a brown bag seminar as a way of introducing myself to the business faculty outside of economics.

I prepared a powerpoint.

That powerpoint got a life of its own on the internet, and someone downloaded it off yet a third person’s faculty website in Taiwan.*

I realized that the VAR slides, “Coming to Your Field Soon: A Primer on VAR’s and VECM’s”, that I just downloaded … may be yours, indicated by the footnote “Dave Tufte's Primer on VAR's and VECM's”. It is a truly a great introduction to VAR. Explaining the ideas underlying the math formulas is quite difficult but very helpful. I just want to thank you for it.

* It looks like they were posted there innocently. We’ve all got stuff we should have linked to, but downloaded instead.

Technorati Tags: vecm,var

Big Recommendation for 1DollarScan!

What an amazing service!

They will scan your books at the rate of 100 pages for a buck. What’s the catch: they recycle the book, so you don’t get it back.

I needed to test this out.

But, what could I sacrifice? I settled on an atlas from 1960 that had been among my dad’s stuff when he passed away.

I love old atlases that show things that aren’t there any more, and I had no special attachment to this physical book … so off it went.

For $2 I was able to download a 400 Mb PDF file of all 184 pages of the book. It took about a month.

And I am so pleased with the quality. Here is my state, scanned from what was perhaps a 10 x 13 page:

The image above is actually a thumbnail managed by Typepad; if you want to see the real deal, click here.

But you’d probably like to see the detail, so here’s my county at 4x magnification:

Note that I-15 wasn’t built yet, and that route 61 is shown as a major road … even though it is now a gravel road out to a ghost town, and no longer carries that state route number. A local expert might note that the shading for mountains is more artistic than accurate.

And if you go down to 64x, here are the individual pixels, clear and readable:

Also, they scanned all the tables and the index, and they’re clear and readable. Here’s a snapshot in time of when Las Vegas was not a major city of the world, but London, Ontario was … and when atlases used to include great data like this:

The image above is actually a thumbnail managed by Typepad; if you want to see the real deal, click here.

I can’t wait to start getting rid of some other books this way.

Hat tip to bookofjoe for pointing me to this service.

Technorati Tags: 1dollarscan,atlas

Creed Bratton, 45 Years Ago

Creed is the awesomely flaky older guy on The Office.

Most people don’t know that he was also the lead guitarist of The Grass Roots. Here they are on the Jimmy Durante Show in the late 1960s. Look for a close-up of Creed around the 1:50 mark:

Via bookofjoe who noted that the lead singer passed away recently.

Technorati Tags: creed,bratton,grass,roots,office

This Really Works: Trick for Cooling Off a Hot Car Interior

I picked this up at Lifehacker: open a window on one side, go to the other side and swing a door open and (just about) closed 5 times.

It really does cool your car off quite a lot — great for my black leather in the high desert summer.

Technorati Tags: cool,your,car,interior

Dialects of American English (Canadian Too!)

Here’s an extremely detailed hobby site, complete with links to sound samples, and awesome maps of dialects or spoken English in North America.

Do click through, as the author clearly isn’t making their maps friendly to deep linking.

Via Kottke.

Technorati Tags: dialect,regional,american,english

The Internet Is Changing Everything

Some people still don’t get it. Here’s another example: a real time, Google Maps crowdsource mash-up of local marijuana prices and quality.

Salt Lake City is apparently loaded with high-quality stuff, but the prices for it are good.

So, let me get this right. We’re fighting a 20th century style police action in an incompletely developed country, and more people are dying there in drug murders than they are of overdoses here. And, most people in favor of that probably can’t conceive of a website like this. And they vote.

Via Paul Kedrosky’s Infectious Greed.

Technorati Tags: marijuana,price