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3h
awarded  Good Answer
2d
awarded  Nice Answer
Aug
23
comment ToExpression from commandline
@acl Yes, I think you're right.
Aug
23
answered ToExpression from commandline
Aug
23
revised Mathematica 10 Dataset doesn't format more than 4 columns?
added 43 characters in body
Aug
22
comment How to generate random points in a region?
FindInstance is not a random number generator. There's no guarantee that it will give you uncorrelated random numbers with a uniform distribution. What the OP is asking for a misuse of FindInstance that is going to lead to wrong results.
Aug
22
comment How to generate random points in a region?
FindInstance is not for generating random numbers ... If you already have the disks, it's trivial to find an instance of a point which lies within them. Take the centre of any disk. It doesn't even matter that you have several disks, you can just use a single one. If you have any expectation that these numbers will be uncorrelated and uniformly distributed (within the disks) then do not use FindInstance.
Aug
22
awarded  Necromancer
Aug
21
awarded  Nice Answer
Aug
21
revised Export dataset to JSON
deleted 1 character in body
Aug
21
comment How do you convert a string containing a number in C scientific notation to a Mathematica number?
Thank you Carlo, this is much appreciated!
Aug
21
revised Export dataset to JSON
added 197 characters in body
Aug
21
revised Export dataset to JSON
added 505 characters in body
Aug
21
awarded  Nice Question
Aug
20
comment GroupBy several keys while keeping the Dataset as a Table (List of Associations)
... <| "a" -> 1, "b" -> 2 |>. This is what Apply is good for: change the head Rule (i.e. ->) into something else. What we need here is to change it to Join. Apply[Join][...] is equivalent to Apply[Join, ...] so we can use the form Apply[Join]. I hope this clears it up a bit. Regarding this method, while it works, it's probably not efficient and I am not really happy with it. I find it too convoluted. I am hoping for something simpler ... I'm not yet experienced with Dataset, and even though my answer got accepted, I'm not too confident about it.
Aug
20
comment GroupBy several keys while keeping the Dataset as a Table (List of Associations)
@MitchellKaplan This dataset contains an association, the keys of which are also associations. Normal will convert this outer association, which has the form <| <|...|> -> <| "Sales" -> 1 |>, <|...|> -> <| "Sales" -> 2 |>, ... |> to a simple list of rules, { <|...|> -> <| "Sales" -> 1 |>, <|...|> -> <| "Sales" -> 2 |>, ... }. You can see e.g. the first element of this list using ...[Normal][1]. Now what we want to do is join the left-hand-side of -> together with its right-hand-side into a single association. Instead of having <| "a" -> 1 |> -> <| "b" -> 2 |> we want ...
Aug
20
revised Will Version 9 functions all work in Version 10?
edited body
Aug
20
revised InstallR on OS X with external R installation
edited body
Aug
20
answered Installing R packages using RLink on Mac OS X
Aug
20
awarded  Enlightened