chombier

17 ms·

121.
by chombier 7y ago
Apart from the exterior algebra part, there is little added value to using geometric algebra compared to other representations. My guess is that most applications don't really need exterior algebra, or at least they would not benefit m
122.
by chombier 7y ago
Sure but I mean most work on algebraic effects (or at least the papers I know of) deals with the associated type system . Instead most people here seem to focus on the semantics, which indeed boil down to call/cc + handlers or previou
123.
by chombier 7y ago
Apparently this construction always provides the (outer) semi-direct product of the Lie group by its Lie algebra with respect to the group adjoint. This also means we should get another one considering body-fixed velocities instead, which I
124.
by chombier 7y ago
Here is a tentative explanation: Dual numbers introduce a constant `eps` whose purpose is to cancel out anything second-order and more. A dual number a + eps * b can be thought of as encoding a tangent vector at position a, with velocity b.
125.
by chombier 7y ago
Near the end of the article: > Because algebraic effects are coming from statically typed languages, much of the debate about them centers on the ways they can be expressed in types. This is no doubt important but can also make it challe
126.
by chombier 7y ago
In my experience, dual quaternions have little to no practical interest unless you need to blend rigid transformations, in which case they provide a cheap projection operator similar to quaternion normalization. (See that SIGGRAPH paper by
127.
by chombier 7y ago
C++ templates are a kind of duck typing, aren't they?
128.
by chombier 7y ago
I wonder what will happen on the day he's supposed to open-source this thing. Delete everything and run away with the money? Kick down the can and delay source release once more? Apologies? ("but but it's pre-alpha software!&
129.
by chombier 7y ago
For a few moments I thought of all these years during which I could have just typed "breakpoint" instead of "import pdb; pdb.set_trace()". Luckily it's been added only recently (3.7) :)
130.
by chombier 7y ago
I am currently reading it, it is very nicely written and accessible. Each chapter starts off gently so you can skip to the next whenever you feel lost, only to come back later. So far: introduction/preorders, monoidal preorders/wi
131.
by chombier 8y ago
M-x secret-handshake
132.
by chombier 8y ago
Government also needs to tax to ensure sufficient demand for its money ("taxes drive money")
133.
by chombier 8y ago
It started as a joke. It's called "modern" because it only applies to the past 4000 years. https://www.nakedcapitalism.com/2018/10/randy-wray-modern-mo...
134.
by chombier 8y ago
MMT without job guarantee is not quite MMT.
135.
by chombier 8y ago
So most notable new language features are modules, coroutines, concepts and contracts. That's huge! I remember vaguely that there were some issues with the initial module proposal and multiple (concurrent :) coroutine designs. Does any
136.
by chombier 8y ago
After quickly scanning the summary and first chapters, it looks pretty similar to MLS94, perhaps a little more approachable.
137.
by chombier 8y ago
> We just took this idea to its logical extreme: What if we _define_ a deep net as a continuously evolving system? What about symmetries of the underlying continuous system? I'm under the impression that having deep nets as ODEs sho
138.
by chombier 8y ago
That's a really nice explanation, thanks.
139.
by chombier 8y ago
I don't get it: why use a cumbersome try/catch block to handle an error in the same context when one could just use the so-called "C equivalent": ... if (condition1) handle_exception1 (); ... if (condition
140.
by chombier 8y ago
One can write pretty much the same code in python/c++11/whatnot and it also feels quite natural to read: for number in numbers: if number <= 10: continue work(number) Do you have a better example where the
141.
by chombier 8y ago
Does anyone know about the new "Temporal" Gauss-Seidel solver in 4.0? I can't find any reference on it.
142.
by chombier 8y ago
Nice! I like how unit/void arise naturally from empty record/sum types.
143.
by chombier 8y ago
As far as I know, subtyping with polymorphism looks much better since Stephen Dolan's thesis on Algebraic Subtyping http://lambda-the-ultimate.org/node/5393
144.
by chombier 8y ago
less than one minute later he mentions "compiling on the fly" some assembly code https://youtu.be/_2NI6t2r_Hs?t=1944
145.
by chombier 8y ago
I think Rob Pike mentioned it in a recent talk on the history of Unix https://youtu.be/_2NI6t2r_Hs?t=1901
146.
by chombier 8y ago
I stand corrected, thanks a lot! It seems the article mostly deals with the scalar/bivector aspect of it though.
147.
by chombier 8y ago
I don't quite understand why the author opposes quaternions and geometric algebra: the geometric product is almost exactly the formula for multiplying pure imaginary quaternions (up to the real part sign). These are just two constructi
148.
by chombier 8y ago
Really both are the same thing up to group homomorphism (double covering in this case). Dual quaternions only add a cheap way of blending several rigid transformations together, which is useful in computer graphics for skinning meshes aroun
149.
by chombier 8y ago
Dual quaternions offer a cheap projection operator by means of dual normalization (very much like quaternion normalization), which the Lie group perspective does not provide. In fact this is probably the only reason to use dual quaternions
150.
by chombier 8y ago
You just have to show that the quaternion norm is multiplicative, which follows easily from its definition |q|^2 = q * conj(q).

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