Hacker News: ggrothendieck

New comment by ggrothendieck in "Why are UK electricity bills so expensive?"

ggrothendieck — Sat, 21 Dec 2024 00:24:32 +0000

Gas production from the North Sea is low because they imposed onerous windfall surtaxes on it so now it is unattractive to produce.

New comment by ggrothendieck in "Solving 100 Bushels Using Matrix Factorization"

ggrothendieck — Wed, 02 Oct 2024 12:48:39 +0000

In R `nnls` (nonnegative least squares) does not guarantee integrality but in this case does give one solution and it happens to be integral: `library(nnls); nnls(A, b)`

New comment by ggrothendieck in "React for R"

ggrothendieck — Wed, 18 Sep 2024 13:07:24 +0000

The poorman package (on CRAN) implements a lot of tidyverse with no dependencies. Other packages that provide alternate implementations are datawizard and tidytable.

New comment by ggrothendieck in "Rejected from YC. Reason: Because I don't have a cofounder"

ggrothendieck — Sat, 11 May 2024 16:42:26 +0000

We used to call stuff like this "the warm body clause".

New comment by ggrothendieck in "Double-entry bookkeeping as a directed graph"

ggrothendieck — Wed, 10 Apr 2024 17:27:04 +0000

David P. Ellerman has a mathematical approach to accounting based on what he refers to as the Pacioli group. A provisional element of the Pacioli group looks like x//y where x and y are non-negative integers and we form equivalence classes based on x//y and u//v being equivalent if the cross sums x+v and y+u are equal. The group operation is x//y + u//v = (x+u)//(y+v) and the inverse of x//y is y//x . The identity element is 0//0. For more info see, for example, https://ellerman.org/wp-content/uploads/2012/12/DEB-Math-Mag...

New comment by ggrothendieck in "Maersk to cut 10k jobs as shipping demand drops"

ggrothendieck — Sat, 04 Nov 2023 17:20:36 +0000

The HN news title seems inaccurate. This is not necessarily a drop in demand nor is it applicable to all shipping as also suggested by the title.

The article suggests it is an oversupply of container ships with very few ships scrapped as opposed to demand: "The industry invested heavily in new container ships during and after the pandemic to meet strong demand and benefit from record freight rates. A large number of new ships entered the market since the summer with no signs of idling or scrapping, said Clerc."

Furthermore just because container ships were over ordered does not mean that other types of ships were so it is misleading to just refer to shipping in the title. It should be "container shipping".

New comment by ggrothendieck in "Ask HN: Books that teach programming by building a series of small projects?"

ggrothendieck — Tue, 17 Jan 2023 20:49:26 +0000

Per Brinch Handsen, Programming a Personal Computer. Book is online. Interpreter, editor and OS in about 10 KLOC. http://pascal.hansotten.com/per-brinch-hansen/ Also https://news.ycombinator.com/item?id=24913959

New comment by ggrothendieck in "One Year with R"

ggrothendieck — Tue, 22 Mar 2022 17:58:54 +0000

Of course it is possible to screw up but if you don't update your packages and record the date that does not seem to be R's fault.

New comment by ggrothendieck in "One Year with R"

ggrothendieck — Tue, 22 Mar 2022 16:19:32 +0000

The packages that were used in statistics were SAS, SPSS and Stata. perl is not a statistical package and has nowhere near the depth of statistical capabilities of R.

Don't forget that I also mentioned the checkpoint package in my post. You only need to know the date for that, not the version of each of the packages.

In your last paragraph I think you are referring more to software development practices than what is available through R. Simply using R or any language doesn't guarantee this.

New comment by ggrothendieck in "One Year with R"

ggrothendieck — Tue, 22 Mar 2022 13:48:18 +0000

Is the subset R interpreter you wrote available on the net?

New comment by ggrothendieck in "One Year with R"

ggrothendieck — Tue, 22 Mar 2022 12:27:43 +0000

1. Before R commercial statistical packages were mainly used. You can, in principle, just use assembler too and develop everything yourself but it isn't practical. Regarding C/C++ and Fortran, many R packages are, in fact, wrappers around code in those or other languages making it easier to access them. From that point of view R can be regarded as a glue language. 2. Regarding keeping versions straight, all past versions of packages in the CRAN repository are kept on CRAN. Microsoft MRAN repository also maintains histories of packages that can be accessed via the checkpoint package which will install packages as they existed on a given date. Furthermore, install_version in the remotes and devtools packages can install specific versions. 3. Regarding tidyverse dependencies you can reduce the number of packages you load by not using library(tidyverse) and instead load the specific packages you need. This will result in fewer packages being loaded.

New comment by ggrothendieck in "One Year with R"

ggrothendieck — Tue, 22 Mar 2022 11:36:34 +0000

What needs to be added is that before R the reproducibility problem in science was compounded by the fact that analyses were done with proprietary software limiting communication and replication of those analyses. This was and continues to be a major problem, particular in some fields, but at least now there is a common widely used language that can be used to overcome this. I wouldn't focus on idiosyncrasies but rather on the major problem it addresses. Any large system will grow over time and have some inconsistencies but after a while you learn the workarounds so they are less important than the big picture.

New comment by ggrothendieck in "Study findings do not support the use of ivermectin for patients with Covid-19"

ggrothendieck — Sat, 19 Feb 2022 13:25:38 +0000

Furthermore a test just twice as large would be sufficient to determine significance at the 1% level even with a two sided test if the same death rate continued to hold.

  ivm <- c(3, 247-3)
  con <- c(10, 249-10)
  m <- rbind(ivm, con)
  fisher.test(2*m)$p.value  # 2* so that it is twice as large
  ## [1] 0.008490957

New comment by ggrothendieck in "Study findings do not support the use of ivermectin for patients with Covid-19"

ggrothendieck — Sat, 19 Feb 2022 00:59:30 +0000

The Mech Vent and ICU also used two sided tests.

New comment by ggrothendieck in "Study findings do not support the use of ivermectin for patients with Covid-19"

ggrothendieck — Sat, 19 Feb 2022 00:33:05 +0000

Also they say they used the Fisher exact test and got a p value for mortality of 0.09 so it seems they were doing a two-sided test which is the default for fisher.test in R.

  ivm <- c(3, 247-3)
  con <- c(10, 249-10)
  m <- rbind(ivm, con)

  fisher.test(m)$p.value
  ## [1] 0.08809225

However, I think a one sided test could be justified and in that case it is significant at the 5% level.

  fisher.test(m, alternative = "less")$p.value
  ##        ivm 
  ## 0.04541928

New comment by ggrothendieck in "Study findings do not support the use of ivermectin for patients with Covid-19"

ggrothendieck — Fri, 18 Feb 2022 23:42:48 +0000

Not being statistically significant is not a proof that it doesn't work -- it only means they could not reject the possibility that the results were due to chance. The possibility that it slashed the death rate by 3x (which is what happened in the study) when projected to the world wide deaths of ~ 4.5 million would imply saving the lives of 3 million people so it certainly would be worthwhile to check it out. Maybe it was due to chance but maybe it was not.

New comment by ggrothendieck in "Study findings do not support the use of ivermectin for patients with Covid-19"

ggrothendieck — Fri, 18 Feb 2022 22:34:50 +0000

If we look at the secondary endpoints note that 3x as many died in the control group, 2.5x as many needed mechanical ventilation and one third more need to go to the ICU.

            Ivermectin   Control
  n         247          249
  Mech vent   4           10
  ICU         6            8
  Died        3           10

These may not have been primary endpoints and may not have been statistically significant but it does raise the question of whether they would have been significant had a larger sample size been used.

New comment by ggrothendieck in "PRQL – A proposal for a better SQL"

ggrothendieck — Mon, 24 Jan 2022 18:00:25 +0000

The link refers to dplyr not being able to use databases but actually there is a database backend for it in package dbplyr. See https://dbplyr.tidyverse.org/

New comment by ggrothendieck in "Teaching a cheap ethernet switch new tricks (2019)"

ggrothendieck — Tue, 28 Sep 2021 11:37:47 +0000

> plug a USB device in that has all my media files on it

If you have multiple radios (like I do) that would require physically moving the USB from one to another.

New comment by ggrothendieck in "Teaching a cheap ethernet switch new tricks (2019)"

ggrothendieck — Tue, 28 Sep 2021 02:37:13 +0000

At the time that CCrane, Grace and others started offering internet radios everyone was using Reciva and articles at the time referred to it as the Microsoft of internet radio so I don't think anyone at the time could have expected its downfall. This was really regarded as the safe bet. Also Grace has not offered a Reciva based radio for quite a few years so you must have quite an old one and have gotten many years of use out of it.

The CC Wifi 3 I got to replace my CC Wifi does have some anti-obsolescence features. It can be used as a bluetooth speaker and it has a built in web server that you can connect into from a browser and manually enter the URLs of streams so even if the Skytunes backend goes defunct like Reciva did the radio should still be somewhat usable.

If your radio can receive bluetooth you could put your media on a uPnP server, access it using vlc on a smartphone and then from there send it via bluetooth to the radio using it as a bluetooth speaker. That is probably more convenient than mucking with the radio to select audio files since you can do it on your smartphone with a better user interface. Anyways, that is what I do.