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6:17 AM
@halirutan thanks a lot.
Installed OS Yosemite and found that Java7 doesn't work -- which in turn meant Mma didn't open. The options appear to be to go back to Java 6 (which is what the popup warning says) or go to Java 8 ...which appears to be what Oracle say. Does anyone have any advice? thanks in advance
1 hour later…
7:28 AM
@halirutan please do post your code up as it is of general interest?
2 hours later…
9:43 AM
@MikeHoneychurch I had the same issue but I just installed the suggested java and both, Mathematica version 9 and version 10 work fine.
I was trying to start Mathematica 9 when a popup appeared that it couldn't be opened because of the missing java7 (when I remember correctly). Then I clicked in this warning box on something like More Information and came directly to a Apple help link where I could download the right java. Now, both Mathematica versions work.
@chris Aehmm, which code should I post where?
2 hours later…
11:30 AM
I was thinking of visitGraphBreadthFirst (and I was quoting you:"Before I post the code, …" :o)
@chris Hehe.. but you saw that I gave the code below, right?
12:27 PM
Yes I did
2 hours later…
2:18 PM
So, Append may or may not work with Datasets, while Insert does
cheers, mma!
I really needed to waste two hours on this today.
2:31 PM
Q: Can't get Append to append a record (association) to a dataset

m_goldbergThe Documentation Center item, Computation with Structured Datasets, implies that Append has been extended in V10 to work with datasets. But not on my computer. (I am running on OS X) Here is what I tried: ds = Dataset[{<|"a" -> 1, "b" -> "x"|>, <|"a" -> 2, "b" -> "y"|>, <|"a" ->...

@acl Now if you don't want to waste more than 2 hours in the future, you probably should stay far away from Dataset :)
@rm-rf right
Right now, Dataset is just a glorified JSON pretty printer.
2:50 PM
@jin Any thoughts on this: meta.mathematica.stackexchange.com/q/1411/5 ?
posted on October 21, 2014 by Ed Pegg Jr

For today’s magic show: A century ago, Martin Gardner was born in Oklahoma. He philosophized for his diploma. He wrote on Hex and Tic-Tac-Toe. The Icosian game and polyomino. Flexagons from paper trim, Samuel Loyd, the game of Nim. Digital roots and Soma stairs, mazes, logic, magic squares. Squaring squares, the golden Phi. Solved the [...]

1 hour later…
4:28 PM
@MikeHoneychurch Oracle says that the latest update of Java 7 should work: java.com/en/download/help/mac_10_10.xml But doesn't Mathematica 10 come with its own Java? It's a problem only with 9 and 8, right?
My impression was that most OS X software that requires Java is hard-wired to use Java 6. I use several such programs (yEd, JabRef, IntelliJ) so I just installed Apple's Java 6. They all seem to work fine.
Java 8 could be installed at the same time and it is used for the browser plugin, if enabled, or for applications that explicitly request Java versions greater than 6.
Here's a tutorial on how to "hack" applications to make them use newer Java: intellij-support.jetbrains.com/entries/… I tried it with IntelliJ and JabRef and worked with both (Java 8). But there was a tradeoff: whenever Java 8 is launched, it causes my laptop to switch to NVIDIA graphics, which reduces the battery life considerably. For this reason I chose to stick with Apple's Java 6 to run most of these programs.
4:51 PM
Well, I just tried it with NetLogo and it didn't work.
5:48 PM
Hmmh. Sort of math, data structures and algorithms question: If I have a continuous multinomial (let's say normal) distribution from which I want to pick unbiased variates cheaply, but I'm actually constrained to choosing from large set of discrete per-variate values (fixed per round, but newly randomized set per round), how do I do it? The problem is that it may be quite high-dimensional space and have millions or many orders more of discrete values to consider.
3 hours later…
8:49 PM
@halirutan I ended up just going with the apple link to java 6.
@Szabolcs interesting. I wonder if that java 7 fix was just made available because I thought I'd gone to a page that said java 7 didn't work on 10.10 and java 8 was needed? In any case I went back to java 6
9:34 PM
@kirma What are you trying to do?
10:26 PM
A nice problem for Mma:
Q: Stitch a picture

DigitalTraumaI have a large collection of fine art. My toddler is learning to use scissors and glue; lately she has started playing with my art collection. Fortunately she is really quite good with the scissors and cuts things up into perfect squares. She then uses glue to randomly tile the cut-up squares ...

I made some progress, but not enough to solve the whole problem
@belisarius Reminds me of this
(ybeltukov's answer at the bottom)
@Pickett Similar indeed. But I think rotation and being a painting instead of a photo makes things even worse
@belisarius Do you have a different strategy than brute-force?
I wonder out of curiosity. I'm not sure how one would do this, and I think brute-force could be very slow with the extra complications you mention.
@Pickett Nah, but I'm using a Gradient filter instead of pixel matching.
@belisarius ah, ok.
10:38 PM
sorry, gotta go.Be back in an hour

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