bridger

I can't figure out what that one is supposed to mean!

  In short, we’ll trade you iCloud for something great.

Love this subtle dig at iCloud.

I took a class that explained light field photography, but I thought understanding the concepts through static diagrams was difficult. I made a little Mac app that simulates a 2D scene of light sources, lenses, and light-field sensors. The sensors shows their captured output in a graph.

The source is at https://github.com/bridger/optic-workbench

A bit of explanation (and a link to the pre-built binary) is at http://www.bridgermaxwell.com/index.php/blog/optic-workbench....

(Sorry it is only for Macs. I would love to redo it in Javascript someday, once I know Javascript.)

When I was doing this exercise with a friend on Understudy, he found solutions to multiplication and exponentiation too. I'm still trying to wrap my head around the exponentiation. Passing a number to another number?!

  (define (multiply number1 number2)
    (lambda (f)
      (number1 (lambda (x) ((number2 f) x)))))
  
  (define (exponentiate base exponent)
    (exponent base))

I've been making a homemade version of Soylent (http://www.cookingfor20.com/2013/06/18/hacker-school-soylent...) since September. It makes up one or two of my meals each day. I've got to say, I really really like it. I think it has a good chance of catching on. I still love eating out socially, but it has replaced all my my mediocre meals. I can imagine it replacing those aisles and aisles of junk, easy food (cereal, canned soup, mediocre pasta).

That said, I quickly had to come up with a better name than Soylent. I call mine Science (for human consumption). It makes it distinct from food. "Did you get lunch?" "No, I just had Science today."

I am doing the chapter on register machines now. I love the diagrams that show the controller and the data path of the machine. See http://sarabander.github.io/sicp/html/5_002e1.xhtml#g_t5_002...

Scratch and Quartz composer show code in a graphical way. Are there examples of languages that show the data path in a similarly graphical way?

I would love to see how variables relate to each other and other functions (the data path) separated from the order in which these operations actually happen (the controller). It would be an interesting way to debug. For example, variables that get assignment but are never read would be glaringly obvious.

I can certainly see those as the next texts that we add!

I tried to tutor my niece in math using Google Hangouts and various whiteboard apps, but drawing with the mouse / trackpad was pretty difficult. Now we use Understudy and it works great, if I do say so myself.

I am the other guy working on Understudy. The iPad has been the best platform for Understudy so far, but I still have my fingers crossed that Apple builds a better touch screen into their next iPad. Who should I pray to for that wish?

Philipp Schmidt is a big proponent of peer-to-peer learning, and he calls it a pyramid scheme himself. :P http://dmlcentral.net/blog/philipp-schmidt/great-peer-learni...

I am working on a startup, Understudy, that tries to address this problem. Our approach is one-on-one conversations. We find you someone to meet with each week as you go through a book. The first one we are doing is SICP. You meet up with video chat and a whiteboard on the iPad. https://www.youtube.com/watch?v=KrdjKvka558

It should be on the App Store soon (awaiting Apple's approval!). If you are interested in trying it, send me an email. bridger@understudyapp.com

"...numbers that are at or near the highest levels of political and religious disaffiliation recorded for any generation in the last quarter-century." Seriously. How many generations are in a 25-year span?

For me, I found the best was when I had the notes printed out before class. I would annotate them with extra thoughts as I watched the lecture. This kept me engaged, but not so busy writing that I couldn't actually think about the lecture.

It turns out Bitcoin was in our hearts all along.

I would still recommend using Auto Layout, even if you are laying out your views without Interface Builder. (Full disclosure, I helped write Auto Layout.)

One advantage is that it makes sure things are pixel-integral, no matter the scale factor of the screen. For example, his code example,

button.x = self.view.width * 0.2; // Position the inset at 20% of the width.

has a pretty good chance at starting the button at x=21.845, or some other point in-between pixels and producing a blurry line. If you do this same relation in Auto Layout, the engine makes sure that the positions and widths are all pixel-integral.

This is not as simple as just rounding everything, either! For example, if you have two views

[blue][red], you want to make sure you round their shared edge either to the left or to the right. Otherwise, there will be a gap between them. You need to make sure you round their shared edge the same way consistently too, or it will jump back and forth as you resize a window and produce a noticeable jitter.

Also, in that same code example, they set a button's x position to be directly related to the width of a view. If you ever want to support RTL interfaces, this is a bad idea. It is relating a width to a position. In a RTL interface, the correct code would be

button.x = self.view.width - self.view.width * 0.2 - button.width

Complicated! In general, you shouldn't convert between positions and sizes. Instead, I would make an invisible spacer view and lay them out like this using the layout format language

|[spacerView][button]

Then make a relation setting the spacerView's width to be 0.2 of the superview's width. This will produce constraints that correctly work in a RTL interface, laying it out like [button][spacerView]|.

Very cool! I have also been making an (iPad) app to help people get through SICP and I somehow didn't run into this.

If anyone is interested in reading SICP now, you should try out my app. We find you someone and you have a good conversation about the material each week through video chat and a whiteboard. We aren't launched yet, but you can check out our simple demo (https://www.youtube.com/watch?v=DlUTKzrqECE) and send me an email if you want to try the beta. bridger@understudyapp.com

I'll bet life was more romantic before spoken language. People weren't busy talking or thinking in anything but emotion and memories of senses. Let's long for those days.

If anyone wants to read SICP and would like a buddy to read it with, let me know! I am working on an iPad app for people to study together and we are trying SICP as one of our first courses. I am reading it for my first time. It is an enlightening book! bridger@understudyapp.com

This is great. The animations and interactive content is greatly needed in mathematics.

One of my favorite parts of math is puzzling over problems and coming up with solutions myself (even if the solution has been known for thousands of years prior.) I wish this book would set up problems I could puzzle over, rather than just give me the solutions before I knew there was a problem!

Am I the only one that wants pictures of these mice flying down in their cardboard and tissue paper parachutes?

Sounds cool!

Working hard at math might be necessary, but it doesn't have to be painful! I have found learning about the history of math has me puzzling over difficult concepts on my own time because it is fun.

The book I am reading (Journey Through Genius) is really good, but not very advanced math. I would love to find some self-study math courses that approach math not as a bunch of symbol-pushing but as an art with a history.