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Giving up on Julia

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Re: Giving up on Julia

#181

Post by Sean1708 »

mathgenius wrote: post #130
yoodenvranx wrote: post #88

As someone who does quite a lot of image and signal processing the fact that their arrays are 1-based is a complete deal breaker. The first few years of my career I worked with Matlab and I hated 1-based arrays with a passion. I think I never encountered a situation where the Matlab way makes stuff easier, almost always the 0-based index is the more natural choice. After I switched to Python/C I can say that I never…

I just cannot comprehend how anyone can use 1-based indexing. I have never used it myself though so there's always the possibility that I may just be missing out on something. Glad that you cleared this up.

I just can't comprehend how something as trivial as indexing can be a deal-breaker for someone. I write 0-based most of the time, but I can think of as many advantages for 1-based indexing as I can for 0-based. The only time I can understand prefering 0-based is in C or something of a similar level, where indexing is just syntactic sugar for pointer arithmetic.

Re: Giving up on Julia

#182

Post by dnautics »

bluecalm wrote: post #148
dnautics wrote: post #95

Earlier quoted context omitted.

You shouldn't be so biased. Having one based indexing makes translating numerical recipes from pure math textbooks (where vectors and matrices are generally one-based) simpler and less error prone. I say this as someone who chafes at Julia's one based indexing as a matter of professional practice.

It's very error prone if you implemented algorithms using 0 based indexing your whole programming life. You are just bound to make mistakes if suddenly it's 1 based indexing. I am not saying 0 based indexing is technically superior (I really have no opinion on that). I could compare it to switching positions of brake and accelerator in a car - you can talk about brake on the right design being superior all you want b…

0-based indexing is technically superior, because it makes offsets for memory addressing simpler.

Re: Giving up on Julia

#183

Post by rixed »

e12e wrote: post #178
jandrese wrote: post #50

Earlier quoted context omitted.

No less than Dykstra has weighed in on the numbering of arrays. http://www.cs.utexas.edu/users/EWD/ewd08xx/EWD831.PDF Having worked with both, I'm inclined to prefer 0 based addressing in most cases. It's slightly less intuitive, but it generally leads to cleaner code.

That argument never felt very convincing to me. Perhaps because it really is about aesthetics, not some deep philosophical ideas connected to numbers. I see it as rather simple. If you're listing off-sets, starting at 0 makes sense, because there'll be something there. But if you're counting elements starting at 1 makes more sense. I don't have 9 fingers offset from my first one, which I call finger zero; I have ten…

Indexing is not for counting elements, it's to reach a particular one.

Re: Giving up on Julia

#185

Post by sgt101 »

vitaut wrote: post #113
bmh100 wrote: post #41

Earlier quoted context omitted.

One-based indexing is also used in Fortran, which seems to be used in a great deal of numerical computing even today. Additionally, BLAS/LAPACK is an important linear algebra library written in Fortan. I am somewhat confused by your discussion of startup times. Since Julia is a "programming language for technical computing", what scenario are you imagining where startup times would be a significant concern?

> what scenario are you imagining where startup times would be a significant concern? Starting a REPL or running a computation that doesn't take long time, adjusting parameters, re-running. Startup time may not be too big in absolute numbers but it's noticeable and adds up quickly especially if you start using more packages rather than toy programs that I used as an example.

Ok that puts some bounds on it; we are talking 1/10ths of seconds as significant? Or 1/2 seconds? There is work on this (https://github.com/JuliaLang/IJulia.jl/issues/346) and later versions of Julia 0.4 feel pretty snappy to me compared to R (which is the other tool I generally use nowadays)

Re: Giving up on Julia

#186

Post by lqdc13 »

MikeHolman wrote: post #94
dagw wrote: post #55

Earlier quoted context omitted.

I've gotten 200x speedup going (badly written) Javascript to (better written) pure python, despite python being a nominally slower language according micro-benchmarks. Comparing run time without knowing anything about the code doesn't say much.

Were you using a js runtime without a JIT? Were your python algorithms better? Otherwise a 200x speedup sounds completely unbelievable. That would basically indicate a bug in the js runtime causing degenerate performance under your scenario.

That's very believable.

Example: popping from the beginning of a list in Python is O(N). Popping from the end is O(1). Initial poorly written code can have a lot of such obvious optimizations.

Re: Giving up on Julia

#187

Post by sgt101 »

SolarNet wrote: post #92
KenoFischer wrote: post #9

Happy to address these points: - Startup performance/memory usage Yes, we are definitely very acutely aware of these. Julia is not currently optimized for frequently run short scripts. That's the price on pays for having to bring up the entire runtime system (initializing the compiler, RNG, external libraries etc). The good news is that there will be a solution to this soon, which is to statically compile your julia…

> - Slowing down in development I think part of this problem is the community, multiple people have reported having bad interactions with core language devs. Also the policies for inclusion of features, how to propose features, how decisions are made with respect to the code base, etc. all seem poorly documented.

I can only speak for myself, I attended an evening "getting started with Julia" event at MIT a few years ago, the devs there were very tolerant of me not being able to do some of the exercises and sat with me and helped me understand. Then they gave me Pizza. I've moaned sometimes about some of the decisions that they've made and they have always responded to me and showed me that they have a good reason for doing what they are doing - even if I still think that might be wrong.

Re: Giving up on Julia

#188

Post by lorenzhs »

kazinator wrote: post #89
lorenzhs wrote: post #87

Earlier quoted context omitted.

Except that's counting, not indexing. It doesn't make sense to compare the two. It's more akin to the "is the first floor the ground floor or the one above it"-debate.

Perhaps you mean it's displacing not indexing? Counting is indexing! What is it that you do when you count items in a set? You put them into correspondence with the natural numbers, indicating each one as 1, 2, 3, ... The last integer is the count. Yes, it is related to the "is the first floor ground, or the one above it"; and it's clear that some programming languages take their cue from stairs and elevators. Nobody…

Since we can probably agree that you're not indexing distances or other units of measurement (you can make a piece of string of length sprt(2) centimeters or other irrational lengths!), let's skip the terminology argument. That wasn't my point.

Is skipping the 13th floor a US thing? I don't recall ever seeing it in the UK or Germany.

Re: Giving up on Julia

#189

Post by sgt101 »

SolarNet wrote: post #164
chrispeel wrote: post #145

Earlier quoted context omitted.

I have never had a bad interaction with the core language devs. OTOH, they are passionate about the language; I've found all the core developers I've met very helpful.

I'm referring to one specific core dev. However they all know each other from MIT so it makes it difficult for them to deal with that fact. I can point to 3 public examples, in addition to a couple of private reports about problems which allow me to be certain. But admittedly it's all second hand to me (from people who work close to the language).

Perhaps you might consider adding a note to your first post making it clear that you are identifying a problem with one other person rather than the whole community and that this is all second hand rather than your own experience?

Re: Giving up on Julia

#190

Post by [deleted] »

SolarNet wrote: post #164
chrispeel wrote: post #145

Earlier quoted context omitted.

I have never had a bad interaction with the core language devs. OTOH, they are passionate about the language; I've found all the core developers I've met very helpful.

I'm referring to one specific core dev. However they all know each other from MIT so it makes it difficult for them to deal with that fact. I can point to 3 public examples, in addition to a couple of private reports about problems which allow me to be certain. But admittedly it's all second hand to me (from people who work close to the language).

[deleted]
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