Chinook Example Database

September 1, 2015

I’m developing new material for a course on semi-structured data, so I’ve been looking for examples. Since we are going to incorporate a SQL bit, I need me some nice SQL databases. The Chinook example database looks really promising. It’s derived from the iTunes XML, which is really nice for my purposes as we can compare models and queries directly. Students could even generated their own example databases from their own iTunes, which is cool.

Where it sorta fails for me as it stands is that it doesn’t clearly expose interesting modelling choices. It is sort of an existence proof that XML like features are unnecessary.

(These address tables are nice in that respect. It’s clear why you might want to factor multiple phone numbers into a separate table and having UK vs. US addresses is a good forcing function for thinking about wacky variation and how easy it is to overfit.)

(There was an awesome site with hundreds of simple ER diagrams/schemas for all sorts of common scenarios, most quite small. I can’t find it at the moment, grr!)


Writer’s Block Ad Nauseam

August 31, 2015

I made some breakthroughs last week (partly by staying home so that I could hang out some with Zoe before she left), but the most important current writing tasks (i.e., my classes which start in a few weeks) is an ongoing brutal struggle.

My brain seem all over the place and rather creative up to the point wherein I try to make it tangible. Then, wreck and ruin.

Sigh.

But hey, two posts in a row!


Music Monday: Ring of Keys

August 31, 2015

It’s a bank  holiday here in the UK and it’s Labor day weekend in the US next weekend. So I straddle two mismatched Mondays where half my life is on vacation and half off. I doubt I’ll get both off, but it’s worth a shot!

We saw Fun Home on Broadway a while back. If you’ve not read the book, you must. It is wonderful. I’ve followed Alison Bechtal’s work since the 1980s (oh Dykes to Watch Out For…how I miss you!), but Fun Home is a transcendence.

The musical is pretty damn good too. Well worth seeing. For me, the stand out song is “Ring of Keys.” (Partly because it’s a great song and partly because Sydney Lucas is awesome.)

The chorus is an amazing bit of writing:

Your swagger and your bearing
and the just right clothes you’re wearing
Your short hair and your dungarees
And your lace up boots.

And your keys oh
Your ring of keys.

If you consider the panel from which it’s derived, it’s clear that this passage isn’t quite a transliteration of the panel, but rather a transfiguration:

The panel shows everyone: Alison’s dad with his contemptuous concern; Alison at the cusp of recognition; the delivery women completely unknowing of how her very existence is a lifeline. The text says “surge of joy” but that’s a bit after the panel (as I read it).

The song focuses your attention on young Alison. We aren’t seeing through her eyes, we are seeing her and her epiphany. Like most Bechtal, the details drive the moment but the moment is, well, not beyond the details. The moment is entirely in the details but, again, transfigured. Each of the details (swagger, bearing, lace up boots) fill Alison completely and yet there’s more. The keys are the apotheosis (narratively and musically) and while the metaphor may be thought a bit obvious (I think there are a lot of layers to it), it fits.

(The article is interesting because it discusses the perceived challenges of making the lyrics work without falling flat with a straight audience: ““I was concerned with how to write about butchness for what would presumably be an audience that is not completely made up of lesbians,” Kron recalled. “I didn’t know how Alison could talk about that delivery woman without the audience laughing at her. This is is a stock target of ridicule. I didn’t believe we could do it.””; they did it.)

And of course, the bridge has the very nice bit:

Do you feel my heart saying hi?
In this whole luncheonette
Why am I the only one who see you’re beautiful?

[Spoken]
No, I mean

[Sung]
Handsome!

It got a laugh when we saw it and it was a good laugh. Alison has a double realisation: That the women is (unknown to most) beautiful and that she’s not beautiful but handsome. The second step is her claiming the butch signifiers that had been denied to her. She doesn’t just value them, she owns them.

It’s a great moment in the book too, but with a completely different valance. I love going back and forth between them.

(The book’s most magical moment is at the end.)

 


What to the white American is Juneteenth?

June 20, 2015

This is really a “notes toward” rather than a fully fleshed out essay. 

The title is a play on the classic Fredrick Douglass piece “What to the Slave is the Fourth of July?” which I urge you to read.

Three paragraphs stand out to me when I read them this Juneteenth:

But, such is not the state of the case. I say it with a sad sense of the disparity between us. I am not included within the pale of this glorious anniversary! Your high independence only reveals the immeasurable distance between us. The blessings in which you, this day, rejoice, are not enjoyed in common. — The rich inheritance of justice, liberty, prosperity and independence, bequeathed by your fathers, is shared by you, not by me. The sunlight that brought life and healing to you, has brought stripes and death to me. This Fourth [of] July is yours, not mineYou may rejoice, I must mourn. To drag a man in fetters into the grand illuminated temple of liberty, and call upon him to join you in joyous anthems, were inhuman mockery and sacrilegious irony. Do you mean, citizens, to mock me, by asking me to speak to-day? If so, there is a parallel to your conduct. And let me warn you that it is dangerous to copy the example of a nation whose crimes, lowering up to heaven, were thrown down by the breath of the Almighty, burying that nation in irrecoverable ruin! I can to-day take up the plaintive lament of a peeled and woe-smitten people!

and

Fellow-citizens; above your national, tumultuous joy, I hear the mournful wail of millions! whose chains, heavy and grievous yesterday, are, to-day, rendered more intolerable by the jubilee shouts that reach them. If I do forget, if I do not faithfully remember those bleeding children of sorrow this day, “may my right hand forget her cunning, and may my tongue cleave to the roof of my mouth!” To forget them, to pass lightly over their wrongs, and to chime in with the popular theme, would be treason most scandalous and shocking, and would make me a reproach before God and the world. My subject, then fellow-citizens, is AMERICAN SLAVERY. I shall see, this day, and its popular characteristics, from the slave’s point of view. Standing, there, identified with the American bondman, making his wrongs mine, I do not hesitate to declare, with all my soul, that the character and conduct of this nation never looked blacker to me than on this 4th of July! Whether we turn to the declarations of the past, or to the professions of the present, the conduct of the nation seems equally hideous and revolting. America is false to the past, false to the present, and solemnly binds herself to be false to the future.

and, finally:

What, to the American slave, is your 4th of July? I answer: a day that reveals to him, more than all other days in the year, the gross injustice and cruelty to which he is the constant victim. To him, your celebration is a sham; your boasted liberty, an unholy license; your national greatness, swelling vanity; your sounds of rejoicing are empty and heartless; your denunciations of tyrants, brass fronted impudence; your shouts of liberty and equality, hollow mockery; your prayers and hymns, your sermons and thanksgivings, with all your religious parade, and solemnity, are, to him, mere bombast, fraud, deception, impiety, and hypocrisy — a thin veil to cover up crimes which would disgrace a nation of savages. There is not a nation on the earth guilty of practices, more shocking and bloody, than are the people of these United States, at this very hour.

Juneteenth is an answer or the start of an answer. We know what Juneteenth was to the American slave as the American slave created it to celebrate the ending of their slavery. Between the first Juneteenth and today we have not yet fully become one society where all our citizens are treated with fully equal respect and regard. But between the first 4th of July and the first Juneteenth, we  moved from a society where slavery was deeply embedded to one where it was ended (though we are still dealing with the aftermath today).

Juneteenth says to me that the United States can change even on something that seemed so deep and powerful that it took treason and a bloody war to slay. So Juneteenth gives me hope that the full redemption of 4th of July is possible.

 


The Liberty Principle, Gay Marriage, and Sleeping Under Bridges

January 6, 2015

There is much to dislike about McAdams’s bog-standard right-wing “omg, PCness in the university” attacking Cheryl Abbate, with a fair number of the issues articulated in several Daily Nous posts. There are a lot of academic freedom bits to think about in everything from how Abbate handled the student, to McAdams’s response, to the university’s response to McAdams. At first blush, basically everyone except Abbate has behaved rather badly. (Really, Mr. Undergrad? You secretly taped your instructor during a fishing expedition? Sheesh.)

I do think the question she raised in class (roughly, what are some positions that conflict with Rawls’ Liberty principle) and the particular proposition (gay marriage bans or lack of gay marriage conflicts with the Liberty principle) is pretty interesting. So that’s what this blog post is about. I’m going to go with the minimal level of scholarship I can get away with as I don’t have any texts handy and don’t feel like futzing around to get them.

Rawls’ Liberty principle goes roughly (since there are some variants):

Each person has the same indefeasible claim to a fully adequate scheme of equal basic liberties, which scheme is compatible with the same scheme of liberties for all;

Now, there are a range of anti-gay marriage legal situations possible. Gay marriage might be unrecognised by the state in a variety of ways (e.g., there’s a legally identical status which is not called “marriage”; there’s a related status, but it doesn’t function the same way e.g., it allows for joint tax returns but only overridable next of kin status). Gay marriage or gay marriage recognition might be affirmatively banned (again, in a variety of ways up to making any sort of homosexual relationship illegal and harshly punished). The basic situation I’ll consider is that we have a legally recognised relationship called “marriage” which has roughly the set of formal and informal benefits and privileges that marriage in the US has and is restricted to opposite sex couples. (I’ll call this the Moderately Sucky Regime (MSR). It’s only moderately sucky because there aren’t punishments for being in a gay relationship and yes this is grading on a curve.) Is this permitted by the Liberty principle?

The “Duh It’s Incompatible” Line

I think this should be the obvious, default starting place. Take two women, Mary1 and Mary2 who different only in that Mary1 loves Juan (a cis-hetero-man) and Mary2 loves Juanita (a cis-lebsian-woman). In the MSR, Mary1 has right to marry Juan (assuming e.g., they both want to get married, they both aren’t otherwise currently  married, etc., so ceteris paribus), but Mary2 does not have the right to marry Juanita. Marrying is either a fairly basic liberty or it’s heavily implicated in a number of basic liberties or it is implied by some basic liberties (various forms of association, for example).

I take it most people think it’s a basic liberty these days. So this argument sets the burden appropriately.

The Majestic Awesomeness of Freedom to Marry Only Outside Your Orientation

There is the oft-quote Faux Liberty Principle (Anatole France):

The law, in its majestic equality, forbids rich and poor alike to sleep under bridges, beg in the streets or steal bread.

This is a principle driven by formalist equality: As long as there is no formal or perhaps explicit inclusion of group distinction, then the law treats those groups equally. The application of this variant of the principle to gay marriage would be something like:

Hey! Mary2 can get married…to a person of the opposite sex. EVERYONE can get married to someone of the opposite sex. Even straight folks can’t marry people of the same sex. So everyone has exactly the same rights!!!

I think this is a possibly non-homophobic attempt to reconcile anti-gay-marriage with the Liberty principle. Indeed, it could be offered as a reductio of the Liberty principle as a sufficient or correct or useful principle of justice.

Now, with respect to the Abbate case, it’s important to note that the gay marriage instance of the Majestic Equality reading, while justifying the MSR, is not the only instance. The original one will do nicely. One can run it for less controversial marriage situations as well as many other disparate impact laws. The gay marriage version is merely timely not uniquely good. Timely topics can be pedagogically effective but they can also be a pedagogic disaster. This is easily seen when the learning outcome has little to do with the timely topic per se. As timely, you run the risk that people will be too engaged with it either because they have settled and passionate opinions or they just can’t easily separate out the public focus from what’s needed to make the classroom point. So the benefit (the students have knowledge and interest) can be a problem.

This is putting aside the possibility that people might behave badly to the detriment of other students or a reliantly hammering on even the non-homophobic variant might be unduly and pointlessly upsetting to other students. You don’t have to think that one must shield students from every uncomfortable thing to acknowledge that upsetting students in a class when there is no pedagogic benefit attached to it is something that should be avoided. Confusing students can be pedagogically useful as well, but that doesn’t justify all confusings.

The Inadequacy of Majestic Equality

Majestic equality fails because a majestically equal scheme of basic liberties might not be a fully adequate scheme of equal basic liberties. Indeed, it’s trivial to generate loads of obviously bonkers schemes of majestically equal basic liberties: E.g., consider a law which forbids advocacy of Republican (or Democratic) political positions. Hey! They affect everyone equally! Or consider a law forbidding belonging to a Christian religion. Hey! Muslims and atheists are forbidden from joining Catholicism as well! EQUALITY!!! Etc. etc. etc.

Clearly, that a law doesn’t carve out a set of persons by name for specifically restricted liberty doesn’t mean it doesn’t, essentially, restrict liberty for some group. I don’t think it’s at all a stretch to read “fully adequate scheme of equal basic liberties” as excluding such shenanigans. It’s unlikely that purely formal criteria will do the job. (I feel like there must be a theorem to this effect somewhere.)

More Iterations

There are definitely more moves to be made or these can be deepened. However, it’s really easy to get sucked into a US legal discussion or just go into a general discussion of gay marriage. For example, if an anti-er goes for a definitional move, “But ‘marriage’ just MEANS 1 man-1 women because procreation.” (or the “compelling interest” variant), it’s not going to illuminate the Liberty principle very much. Similarly, denying that marriage is a basic right does mean that anti-gay marriage might not violate the Liberty principle per se (though it probably dies on the second principle), but then it’s a bad example. If you do concede it’s a basic right then it’s hard to see how bans aren’t an immediate clash with the liberty principle. If you don’t concede that, then it’s irrelevant. Debating whether it is a basic right is also irrelevant (much of the time) to a discussion of Liberty principle applicability.


Some Philosophy Hiring Data Analysis

December 29, 2014

I got involved in a discussion (on Daily Nous) of Carolyn Dicey Jennings’ data about US (I think) philosophy hires. In was in the context of a characterisation of “the New Consensus”. This all seems somewhat mixed up with the recent Leiterevents, but a lot of themes remind me of stuff I heard in graduate school in the 1990s.

Background

In any case, the initial claim is:

who suggests that Carolyn Dicey Jennings’ data (that women who receive TT jobs have on average half the publications of men who receive TT jobs) indicates that women get preferential treatment

With a follow up by a different commentator:

@JT – CDJ’s attempt to provide an alternative explanation for her data seems rather tortured, and has widely been recognised as such. I agree that we don’t know whether AA in hiring overcompensates for other, previous discrimination.

The alternative explanation (at least the first move):

What is the mean number of publications for women and men in this data set? For all of the jobs (tenure-track, postdoctral, and VAP) and for all peer-reviewed publications, placed women have an average of 1.13 publications, whereas placed men have an average of 2.17 publications. Thus it looks as though placed men have one more publication, on average, than placed women. Yet, if we look at median number of publications, this difference evaporates: the midpoint of publications by both women and  men is 1 publication. (The mode is 0 for each.) Why this difference between mean and median? The difference comes down to those at the extremes: 15% of men and 5% of women have 5+ publications.

Roughly, if you have a distribution of quantities with no upper bound and skewed left in a kinda of long tail, mean as a measure of central tendency is vulnerable to outliers. (This is roughly what I was saying here.)

There are several other interesting posts by Philippe Lemoine. I owe them a response, but I’ve started but not finished a line of analysis and want to get an interim report out on that, so I won’t really engage his points yet. Sorry Philippe!

Some Considerations

First, it’s clear that this discussion could get pretty cantankerous esp. as things fit or fail to fit various political/policy positions. I’m not yet ready to discuss policy recommendations, but I want to get clear on the data.

Second, my bias is to suspect that the market is disproportionately adversarial to women. Considerations of implicit bias (though in conflict with positive action) etc. would suggest this straight off. However, I don’t know that initial tenure track hires is a place where this plays out strongly. Regardless, I will definitely be inclined to keep looking when analysis suggests otherwise and this raises a risk of confirmation bias even if I don’t delude myself about any piece of analysis. Fortunately, Philippe seems to have different priors so this might help. I’m pretty cognisant of this problem which can help.

Also, the current analyses are really just too shallow to say much in any direction. I think e.g., Philippe, me, and CDJ all agree on this.

Third, if it turns out that the TT job market isn’t unduly adversarial for women, I will be delighted. This is a great outcome. If it is unduly and unjustifiably adversarial for other groups that will not be good, but I don’t want to ignore the good. Lack of negative bias against women in hiring is a good thing.

Fourth, the data are probably not even close to sufficient to making strong conclusions, if only because we don’t know what the unsuccessful candidate pool looks like. But also,

  • I’m pretty sure publication number are not the only consideration in determining a good candidate. Indeed, there’s plenty of prima facie reasons to supposed it’s not even correlated with overall quality, e.g., possible trade offs between teaching and research or quantity and quality.
  • Gender might be correlated with other properties, e.g., program ranking which might dominate. I.e., when you control for the other factor, differences seemingly due to gender might disappear.
  • Most of these candidates (I think!?) didn’t compete with each other as they weren’t all applying for the same pool of jobs. Some jobs might be out of reach due to AOS or might have been less desirable due to location or dept. We need a model of how the decision making might be unduly influenced and preferably at least an operational notion of problematic bias.
  • And, I’ll just repeat and following on from the prior point, without some idea about the unsuccessful pool, it’s hard to make conclusions about why the current set got in. After all, you don’t need to beat out the other successful candidates for other jobs, just the unsuccessful ones for your job. If the whole pool of unsuccessful candidates is worse than the whole pool of successful candidates (and the head to heads are appropriately distributed), then the differences between the male and female pools of successful candidates are not evidence of bias in selection, just differences in the cohort.

Toward the “weight at the high end” hypothesis

So, my first move, I’ve broken out the data in two ways:

  1. I separate out by year (2012 and 2013). There’s three reasons for this: a) candidates primarily compete within a year (esp. successful ones…I presume most successful candidates for a TT position don’t go on the job market the very next year; if you did so, I’d love to hear why!), b) the selection committees and positions are different from year to year, and c) the first time through I tried to do it in Excel and for some reason I found it easier to start with 2012 alone and it kinda stuck through. What? Analysis isn’t always pretty, y’know!
  2. Within each year I break down the male and female cohorts by number of publications so we can get a more precise view of the distribution.

Method: I imported Data 2 from CDJ’s spreadsheet into BaseX and ran some queries to extract the first three columns for each set, then Excelled the rest. I’ll release the whole thing when I have it a bit further along. I’m using the “PR_Pubs”.

Here are the tables (sorry for the screenshots, but WP is sucking for me now; I need to decide whether to go premium or just move the blog):

screenshot_04

Key: Pub Ct = Number of publications for a candidate. PubTotal = The cumulative number of publications for the cohort up to that row. CumAvg = The average number of publications for the cohort up to that row. Cum%=the percentage of that cohort up to that row. % of all=the percentage of the cohort appearing in that row. The totals are the total number of candidates.

I didn’t break out the medians per se, though you can sorta see where they’ll be. The first thing I noticed is that where the “CumAvg”s diverge: In 2012…huh! Well, in one version when I rounded to one decimal place, they didn’t diverge until 3 pubs (whereas in 2013, they diverge after 0). Here, they diverge at 1 because I’m not rounding/truncing/whatever Excel does before then. Hmmm. And of course, if you Whatever to the integer, divergence starts happening at 7 (2012) or 6 (2013).

I’m really not sure how to go here. On the one hand, a difference in averages of 0.03 papers doesn’t seem very meaningful. On the other hand, a difference of 0.6 does seem meaningful. I guess, the key think is that there is a lean toward the male cohort even when the differences aren’t very meaningful. So I’ll leave that as it is for the moment.

In 2012, 94% of the women and 73% of the men had 3 or under publications. 2013 had a higher publication year for both cohorts. What’s interesting to me is that the 0-pub percentage stays roughly at 1/3 for the men and a bit under 1/2 for the women across both years. There’s a bit of shuffling at the 1s and 2s, with the 2012 cohort outperforming the men (as percentages) in 1s and 2s (which helps explain why their divergence is delayed in 2012).

Overall, men outnumber women 2 to 1. This means there’s more “room” for more exceptional candidates (publicationwise) in a sense.

So what does this mean? Got me. These years, the successful women candidate cohort had more 0s and fewer of the high end. But it’s not clear what the “natural” rate should be. (John Proveti mentioned that if we have a lot of female continental candidates, they may be more book than paper oriented and that might make a difference.)

The jump between the % of women with 1 pub in 2012 (30%) and 2013 (22%) makes me a bit wary (esp. when it’s the same number of women :))

Conclusions

Well, it’s all rather tentative at the moment. I guess my first thought is that these data don’t show any evidence that women at being discriminated against at the TT hiring level. If only like 2% of women had 0 and most 1 where the male numbers stayed the same, that would be pretty striking. Similar in the reverse. But that’s not the case. What we have is a lot of 0s, a fair bit of 1s and maybe 2s, and then a lot of variation. The curves look pretty similar:

screenshot_05

My second thought is that I find the gap in the 0s more concerning than the gap at the high end. I’m not quite sure whether this is well grounded or not. My intuition is that large number of publications aren’t really typical, but 0 vs. 1 might be significant. Either way, I want to know what’s going on and whether this is predictive of publication in the future (or or success in getting tenure).

My third thought is that I still don’t know if sex is a selection bias, but this data doesn’t rule it out for sure. Whether you find it suggestive of pro-woman bias depends at this point, I’d warrant, on your priors, more than anything else. But I think I agree with Philippe that my simple conceptual example (where a couple of outliers at the high end really mess things up) is probably not what’s going on here, though I don’t see that:

Of course, when the mean number of publications is greater for men than for women even though the median is the same, it’s also conceivable that it’s because a handful of men have a very large number of publications. But, for this to explain a difference between the mean numbers of publications as significant as that which Carolyn found, the number of publications of those men would really have to be ridiculous. So ridiculous that we can pretty much rule out this possibility at the outset, because we know that nobody goes on the market with that many publications.

I’m not sure what would count as a “handful”, but at least in 2012 we have 3 people with 12 and 1 with 14. If we added 3 with 14 (for 4 in total), we move the culm average from 2.06 to 2.27 for men. So significant movement can be made with small numbers within the bound of what existed. Now that’s not the full difference, but it’s non-neglible. So I’m not sure it was “ridiculous”. Of course, it’s not quite the case, so I’m happy to concede the point in this instance for the moment. (Hedge!)

I would hope this is “needless to say”, but all this is rather preliminary and there may be all sorts of errors not least in the translation to blog post. Corrections and suggestions most welcome.


Music Monday: War on Xmas 2014

December 22, 2014

Xmas and New Year’s are on respective Thursdays. Wacky.

It does seem that in recent years the War on Xmas has wound down. As a dedicated soldier fighting against Xmas in all its forms, let me wish you a Happy Holidays, Season’s Greetings, and a hearty Solstice Salaam.

The most important front in the War on Xmas is, of course, music. The oppressive Xmas hegemony controls most public spaces and assaults us with endless aural evil of which we will not speak in detail lest we invoke insidious earworms! However, the revolutionary anti-Xmas cadres do, on occasion, produce effective musical blows against the saccharine onslaught! Here are a few of the more stirring.

The Waitresses: Xmas Wrapping

While covered to detriment (we’re hating on you Spice Girls and Glee, for two), the original is still wonderful in spite of the happy ending.

The ultimate Xmas shaggy dog story. For some reason the following two lines:

“A&P” has its provided me
With the world’s smallest turkey

make me really happy. I think it’s the combination of nostalgia for the “A&P” (I’ve not been in one in decades…do they still exist?) and the turkey. The poor poor inadequate yet appropriate turkey.

The Kinks: Father Xmas

Would any War on Xmas be complete without The Kinks delicately singing:

Father Christmas, give us some money
Don’t mess around with those silly toys
We’ll beat you up if you don’t hand it over
We want your bread so don’t make us annoyed
Give all the toys to the little rich boys

I think not!

(I’d prefer a flame thrower to a machine gun, of course.)

The Twelve Days after Xmas

This is also a favorite but there really is no worthwhile video. (OMG, it’s easy to do such a horrible performance of it that it almost becomes a Pro-Xmas song, even with all the bird carnage. “Enjoy” this one, if you dare.)

Of course, quality War on Xmas songs are rare. It’s not enough to be a parody or crabby Xmas song. We aim for quality! Here are some negative examples:

The Killers: Don’t Shoot Me Santa

Go ahead and shoot, Santa. Then eat a bullet.

After listening to this song and watching bits of the so-called video, I feel a Santanic  murder-suicide is totally appropriate.

The Ramones: Merry Christmas (I Don’t Want To Fight Tonight)

Ok, I didn’t want someone to die listening to this, but it’s just sorta blandly catchy with a really boring set of lyrics.

 


Rounding

December 15, 2014

Just a weird little thing.

When scraping data from a paper (or any source), I grab both the numbers they give including derived numbers and try to rederive the numbers. This provides a couple of sanity checks (e.g., that my scraping was accurate) and gives me their “model” (even if it’s trivial).

Of course, you find stuff!

For example, I’m scraping the breakdown of a population across categories. The size of the population is 73,538 and they give both the number and the percentage in the breakdown. Thus, it’s trivial to rederive the percentage. So that’s what I do, but then I get four values that are off by one:

Paper Rederived
17.9 17.8
59.7 59.6
14.8 14.7
2.6 2.5

So, an off by one error. GRRR! Clearly this is a rounding problem, and looking at the unrounded results confirms this:

Paper Rederived Unrounded
17.9 17.8 17.8492752
59.7 59.6 59.64807311
14.8 14.7 14.74883734
2.6 2.5 2.548342354

Excel is doing the “right” thing here: It only looks at the digit before the target digit. Of course, this sort of rounding is not equivalent to the fixed point iteration (i.e., if I round(17.849) to 2 places I get 17.85 and if I round that to 1 place I get 17.9). But it’s far more common to do things the “right” way. (And it makes a lot of sense.)

What confuses me is how the heck did the paper get the iterated rounding version? Is there software out there that does it that way? My spot checking of Excel, Google Spreadsheets, and Python all yield the same behaviour.

Is this a big deal? Well, obviously not. Arguably, I don’t care about what’s beyond the decimal for these purposes and nothing about these differences is critical — or even  marginally relevant — for the paper’s results. However, it is an interopt and validation problem. What should have been two seconds took me 20 minutes. And what’s this software doing this weird rounding? Is it causing problems elsewhere?


New on the blogroll: Now Face North by the invaluable JL

December 9, 2014

JL is one of my absolutely favorite commenters on Lawyers, Guns, and Money. She is a true standout comment with a wealth of activism and other experience that she readily shares with sharp insight. She now has a blog! Read her blog!


Music Monday: Bad Lip Reading’s “Gang Fight”

December 8, 2014

While I love quite a bit of Bad Lip Reading’s video (the schtick, the dude’s mom went substantially deaf and learned to lip read by watching TV; being a good son, he turned off the sound and tried to learn as well; he’s really and hilariously bad at it), the only song that I like is the Bad Lip Reading of Rebecca Black’s “Friday”.

Fortunately, I don’t know the original and never will!

How can you not love the (very catchy) chorus:

Gang Fight, Gang Fight!
The gang is down to fight, yeah
Have I brought this chicken for us to eat?
Gang Fight! Gang Fight!
The gang is down to fight, yeah
Have I brought this chicken for us to thaw?

I believe the answer to those two questions is always YES! And I’m vegetarian!


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