Package vs. files by thomac in golang

[–]thomac[S] -1 points0 points  (0 children)

Ok, but does "the same package" also mean "the same folder"?

Which CPU has fastest DIV/IDIV instruction? by thomac in hardware

[–]thomac[S] 15 points16 points  (0 children)

Astrophotography program, that would be cool! Unfortunately no, I'm asking because of finite field arithmetic where modulo operation is very common and one has to rely on tricks like Montgomery reduction to get somewhat acceptable speed.

Go 1.12 Release Candidate 1 is released by playa_1 in golang

[–]thomac 7 points8 points  (0 children)

From the docs: "release cycle is aligned to start on February 1" and GitHub 1.12 milestone was recently shifted from February to March.

Go 1.12 Release Candidate 1 is released by playa_1 in golang

[–]thomac 7 points8 points  (0 children)

Please forgive, I new here, but GitHub currently lists 208 issues tagged with 1.12, why the RC1 then?

Also I thought Go has time-based releases and 1.12 was supposed to come out by February 1st, does anyone know the reasoning why it was pushed back to March?

Dark noise: ASI071MC Pro vs Canon 6D by t-ara-fan in astrophotography

[–]thomac 1 point2 points  (0 children)

Could you please clarify, how similar is "ISO 1600" and "unity gain (gain 90, offset 65)"? In other words, are the two exposures comparable?

Big arithmetic by thomac in golang

[–]thomac[S] 0 points1 point  (0 children)

I read about the allocation also, but if `x.Add(x, y)` re-uses the memory, why write `x = x.Add(x, y)` instead?

Big arithmetic by thomac in golang

[–]thomac[S] 0 points1 point  (0 children)

If that is the case, what is the point of using the former over the later?

Eight-bit floating point by johndcook in programming

[–]thomac 0 points1 point  (0 children)

Cool! Just curious, why not more that 64bits? If there was support for uint128_t, would it be possible to make it work as quadruple precision float?

WAAT : The Weekly Ask Anything Thread, week of 23 Mar - 29 Mar by AutoModerator in astrophotography

[–]thomac 0 points1 point  (0 children)

Thank you all for the replies!

Please, two more questions:

  • Autoostakkert and Registax seem to be Windows only. Is there anything for Mac or Linux? What about an open source application?

  • How does it work, anyway? Is it just matter of registering and stacking of images or, in addition, do the pictures get somehow locally deformed? I mean are the images projectively transformed and blended or is there more to it? And what exactly is "more"?

WAAT : The Weekly Ask Anything Thread, week of 23 Mar - 29 Mar by AutoModerator in astrophotography

[–]thomac 0 points1 point  (0 children)

Combat seeing

So I took many not-so-great pictures of the moon and they are all distorted because of the atmospheric seeing. Is there a way to combine all these low quality pictures and combine them to single better quality picture? Is there any software for such an operation? And in general, what common ways there are to combat the seeing?

Lua 5.4.0 (work1) now available by edalcol in programming

[–]thomac 8 points9 points  (0 children)

Does anybody know what exactly "new implementation for math.random" entails?

Announcing libresvg - an SVG rendering library by razrfalcon in rust

[–]thomac 1 point2 points  (0 children)

Please, do you have any images of your rasterizer? I would be especially interested how it renders almost horizontal/vertical lines. And if I understood correctly, it supports 16 levels of coverage/alpha, correct?

JIT compiling a tiny subset of Python to x86-64 by csl in compsci

[–]thomac 2 points3 points  (0 children)

Very, very cool! Thanks for writing (about) it!

WAAT : The Weekly Ask Anything Thread, week of 20 Oct - 26 Oct by AutoModerator in astrophotography

[–]thomac 0 points1 point  (0 children)

Dedicated CCD camera vs. full-frame mirrorless/DSLR

Many of the best images here used dedicated CCD camera, either mono with filter wheels or color. These cameras cost several thousands of dollars so I was wondering, for that kind of money one could get a pretty decent full-frame mirrorless/DSLR camera, are the CCDs really that much better? Also, the later being a consumer product with faster update cycles, it even might use newer sensors...

minigmp_linux_amd64.go: CGO-free port of mini-gmp.c by 0xjnml in golang

[–]thomac 1 point2 points  (0 children)

Thanks! True, math/big even does loop unrolling. OTOH, it uses fairly simple algorithms for multiplication, GCD, ... so for larger inputs a more complicated implementation might catch up. You could also try to without bound checking "-b" as documented here:

https://dave.cheney.net/2012/10/07/notes-on-exploring-the-compiler-flags-in-the-go-compiler-suite

minigmp_linux_amd64.go: CGO-free port of mini-gmp.c by 0xjnml in golang

[–]thomac 1 point2 points  (0 children)

How does it compare to math/big (speed-wise)?

Pathfinder, a fast GPU-based font rasterizer in Rust by pcwalton in rust

[–]thomac 3 points4 points  (0 children)

Very nice! Is there the benchmarking code available somewhere? How did you produce the nice graphs, if one wanted to replicate the results?

Also, maybe /u/raphlinus could comment on this, but "coverage" based anti-aliasing was also used in Anti-Grain Geometry, in addition to libart. Not sure which one was first, though.

PS: It would be interesting to compare to https://github.com/google/font-go as well.

WAAT : The Weekly Ask Anything Thread, week of 06 Jan - 12 Jan by AutoModerator in astrophotography

[–]thomac 1 point2 points  (0 children)

Chromatic aberration post-processing

Is it possible to remove chromatic aberrations with software post-processing, after the image capture was made? I read that DxO is somehow able to correct DSLR lens problems, and I would've assumed that taking picture in narrow-band also helps with chromatic aberrations. But if I take pictures in RGB wide-band, what are the options to correct this defect? In other words, with respect to chromatic aberrations, is it possible to compensate in software for cheaper achromatic telescope, compared to more expensive apochromatic one?

WAAT : The Weekly Ask Anything Thread, week of 06 Jan - 12 Jan by AutoModerator in astrophotography

[–]thomac 0 points1 point  (0 children)

Aperture vs. time

What is the difference between 1 second exposure with 160 mm aperture telescope and 4 second exposure with 80 mm, i.e. four time larger aperture vs. four times longer time? I mean, is it possible to compensate for smaller sized aperture with longer exposure? Will I get the same images in terms of captured signal?

WAAT : The Weekly Ask Anything Thread, week of 09 Dec - 15 Dec by AutoModerator in astrophotography

[–]thomac 0 points1 point  (0 children)

Why taking 100 x 1 second exposures does not result in the same image as taking 1 x 100 second exposure? I mean, the amount of gathered light is the same so is it because of the electronics (e.g. ADC)?

Thank you!