Inkscape Union Thwarted by Singleton Groups

22 September 2022

I encountered a rather odd problem when using Inkscape, a vector graphics program. I was unable to create unions joining two paths because each was in a group with only one a member. I could think of nothing that I'd done that should have created any group, and a group with only one member is an odd thing in any case. I only discovered the grouping because I had eliminated the other possible reasons that the paths should not form a union.

Each of the two paths was originally a text object, entered separately from the other. Perhaps in recent versions of Inkscape text is always in a group, even with just one character.

What We Imagine to Be the Territory Is Usually Another Map

18 September 2022

As is often noted, the map is not the territory.[1] But what is usually missed is that, when we attempt to think of how they differ, we most often slip into specifics such that what we really compare is not the map with the territory, but the thing first recognized to be a map with a mental map of the territory.

Our efforts to think about how models differ from reality are usually likewise characterized by comparisons between some model and some other model not recognized to be a model. When we abandon specifics, and attempt to think of reality in the abstract, we almost always think of what amounts not to reality but to a hypothetical, unknown, perfect model of reality.


[1] with Alfred Habdank Skarbek Korzybski being the first to put it just that way

A Note on a Quote

31 July 2022

When Oliver Cromwell wrote, on 3 August 1650 to the General Assembly of the Church of Scotland,

I beseech you, in the bowels of Christ, think it possible that you may be mistaken.

he was in fact paraphrasing Richard Hooker,

Think ye are Men, deem it not impoſſible for you to err; ſift unpartially your own hearts, whether it be force of Reaſon, or vehemency of Affection, which hath bred and ſtill doth feed theſe Opinions in you.
Preface [1594] § 9
Of the Lawes of Ecclesiastical Politie

(Underscore mine.) In Cromwell's time, and indeed for many years to follow, Hooker's work was widely known and widely respected, and Cromwell had every expectation that his allusion would be recognized for what it were.

Death and Its Complement

26 June 2022

On each side that is allowed a wide audience, public discourse on the subject of abortion is dominated by knaves and by fools. Arguments are offered that don't withstand much scrutiny.

But the overturning of Roe v. Wade will not result in a simple division of states into those that permit abortions in all or in almost all cases and those that forbid it in all or in almost all cases; the supposed dichotomy that has been imposed by insinuation from the commanding heights of our culture will be falsified. While I doubt that the policy adopted soon by any state will be the correct choice, the adoption of a multitude of policies will provoke a larger number of people to think more carefully about the criteria that ought to decide amongst policies.

Confined to the margins of recent discussion has been a very simple and important idea, which is the complement of the concept of brain death. This idea will make its way to the center of discussion.

Virtual Shelving

19 June 2022

[This entry was revised and expanded on 2022:07/07.]

I am always uncomfortable with the process of organizing books and articles on shelves or in boxes. I desire to have them grouped by each author and by each subject of interest; these desires cannot be reconciled without having multiple copies of each book and of each article, which multiplicity I cannot afford.

Electronic copies are a different matter. Even without multiple copies, symbolic links, which I discussed in a previous entry, make it possible effectively to list the same file in multiple directories. Hereïn, I'll explain the principle structure that I use for organizing documents, and I'll present some small utilities that facilitate creating and maintaining that structure on POSIX-compliant file systems. This structure is not as fine-grained as might be imagined, but it strikes a balance appropriate to my purposes. (For a more sophisticated system one should employ an application storing and retrieving documents mediated by a cataloguing relational database.)

As with many systems, mine have each a directory named Documents. Its two subdirectories relevant to this discussion are Authors and Subjects.

The entries in Subjects are subdirectories with names such as Economics, Logic and Probability, Mathematics, and Philosophy.

In turn, the entries in each of these are subdirectories with the names of authors.

Finally, in each of these subdirectories are entries for files containing their work corresponding to the superdirectory. For example, Documents/Subjects/Logic and Probability/Johnson William Ernest/ would have entries for works by him on logic or on probability, but his article on indifference curves would be listed instead in Documents/Subjects/Economics/Johnson William Ernest/.

Most of the subdirectories of Authors have names corresponding to the subdirectories in the third level of the Subjects substructure, but all of these subdirectories in Authors are different directories from those in the Subjects substructure.

Each of most of these subdirectories of Authors lists not subdirectories nor files, but symbolic links. These links take their names from the subdirectories of Subjects, but they do not link to those subdirectories. Instead, each links to an author-specific sub-subdirectory. Thus, for example, Documents/Authors/Johnson William Ernest/Logic and Probability is a symbolic link to Documents/Subjects/Logic and Probability/Johnson William Ernest. It is as if the subject-specific collection of an author's works is the author-specific collection of works on that subject, just as it should be.

One could, instead, use the complementary organization, in which the Subjects substructure were ultimately dependent upon the Authors substructure, or use a hybrid organization in which some of the dependency flows one way and some the other. The determinant should be what is most important to preserve if the collection is copied to a file system that does not support symbolic links, as in the case of a SD card with a FAT file system.

I've sketched the principal structure, but want to note useful complications of two sorts.

The first is that symbolic links may be used to place some subjects effectively under others. For example, logic an probability fall within the scope of philosophy. As well as having a directory named Logic and Probability listed in Subjects, I have a symbolic link to it listed in Philosophy. Indeed, when a subject falls within the intersection of other subjects, each may have such a symbolic link, and I have links to Documents/Subjects/Logic and Probability not only in Philosophy but in Mathematics and in Economics.

The second is that symbolic links may be used effectively to list a document with multiple authors in the directory for each author. And essentially the same device may be used to classify a single document under different subjects.

Although this organization is not especially fine-grained, it requires the creation of many directories and symbolic links. I've written seven utilities in Python to reduce the burden. Two of those utilities were presented in a previous 'blog entry because they can be put to more general purpose. Here, I will present five more.

(Again, these utilities are written for POSIX-compliant file systems. Windows is not POSIX-compliant. A full discussion of the relevant issues would be tedious, as would be an effort to rewrite these programs to support Windows.)

[Read more.]

Cataloguing and Restoring Symlinks

15 June 2022

While one might imagine computer files as stored in something analogous to folders, in reality the directories of file systems are, well, directories. A directory is a file of entries, most of which correspond to names, locations, and other information about other files (some of which may themselves be directories).

But some file systems allow for entries which do not directly provide the location of a file. Instead, these entries — called symbolic links or symlinks — point to other entries. One symbolic link may point to another symbolic link, but it is to be hoped that ultimately an entry is reached that points to a file. A file system will then treat most references to a symbolic link as if they are references to whatever file is indicated by the entry to which the symbolic link ultimately leads. The option of symbolic links allows for different directory entries — possibly with different names and possibly in different directories — effectively to point always to the same file.

I use symbolic links to organize electronic copies of books and articles, so that my directory system categorizes them both by topic and by author, and sometimes by multiple topics or by multiple authors (in the cases of collaborations and of anthologies). But I face the problem that often I want to save these documents using a file system that doesn't support symbolic links.

Not just in this case, but in any case in which I copy to a file system that does not support symbolic links a collection of files in which the directories contain symbolic links, I'd like to be able to restore the entire structure from such a copy.

My solution has been to create a file that catalogues the symbolic links, so that they can be recreated. Of course, I want both the cataloguing and the recreation to be automated. Towards that end, I've written two small programs in Python. These programs will work with any POSIX-compliant operatings system (Linux, MacOS, &c), but Windows is not generally POSIX-compliant.

This program creates a catalogue of symbolic links in the current working directory and in any of its subdirectories, as a set of records with tab-separated variables, and sends it to standard output.

#!/usr/bin/env python
import os

separator = "\t"

def chase_link(link):
    source = os.readlink(link)
    dir_save = os.getcwd()
    os.chdir(link[:link.rindex("/")])
    os.chdir(source[:source.rindex("/")])
    if os.path.islink(source):
        print(source + separator,end="")
        chase_link(source)
    else:
        print(source)
    os.chdir(dir_save)

def search_dir(directory):
    list_dir = [entry for entry in os.scandir(directory)
            if entry.is_dir() or os.path.islink(entry)]
    for entry in list_dir:
        if os.path.islink(entry):
            print(entry.path + separator,end="")
            chase_link(entry.path)
        elif entry.is_dir():
            search_dir(entry)

dir_top = "."

search_dir(dir_top)

And this program reads a catalogue from standard input and recreates symbolic links in the current working directory and subdirectories (recreating subdirectories as necessary).

#!/usr/bin/env python
import os
import os.path
import fileinput

separator = "\t"

def relink(chain):
    dir_start = os.getcwd()
    os.makedirs(chain[0][:chain[0].rindex("/")],0o777,True)
    os.chdir(chain[0][:chain[0].rindex("/")])
    if len(chain) > 2:
        relink(chain[1:])
    link = chain[0][chain[0].rindex("/")+1:]
    if not os.path.exists(link):
        os.symlink(chain[1],link)
    os.chdir(dir_start)

for line in fileinput.input():
    relink(line.rstrip().split(separator))

The reason that you see so much changing of directories in these programs is that they support symbolic links with relative specification. Absolute specification is also supported, but if absolute specification is used for symbolic links then relocating a directory structure is more difficult.

A catalogue created with the first program may have many redundant links. The program could be written to omit these, but that enhancement would come at an expense in programming time and in computing resources that simply doesn't make sense at the scale at which I operate. (Likewise for recoding these programs to work or to fail gracefully with various versions of Windows.) I try not to go crazy with my refinements!

In a later 'blog entry, I'll present some other utilities that I've written more specifically for managing the symbolic links of my files of books and of articles.

Sexual [Meta]-Preferences

20 May 2022

As I noted in an earlier 'blog entry, I use the words choice and choose simply to refer to selection; and, when I say that someone prefers X to Y, I mean that if given a set of mutually exclusive options that include X and Y then Y will never be selected. Some people try to mean something else by one or both of these terms. In the case of choose, they seldom if ever explain what that something might be. R[obert] Duncan Luce proposed to define preference in terms of probability of selection, rather than in an absolute manner as do I; that difference won't bear meaningfully upon what I have to say here.

One might have preferences about one's preferences. For example, preferring-not-to-prefer simultaneously X to Y, Y to Z, and Z to X for any X, Y, and Z. But note that making choices based upon the preferences that one has is different from choosing to have the preferences with which one makes the choice. Choices about preferences are meta-choices; preferences determining meta-choices are meta-preferences.

In theory, all choices could be determined by preferences, all preferences could be meta-chosen, all meta-choices could be determined by meta-preferences, all meta-preferences could be meta-meta-chosen, all meta-meta-choices could be determined by meta-meta-preferences, &c out to any finite level of meta that you might imagine. But the levelling cannot be infinite. At some point, one reaches a level that wasn't chosen. Varieties of choices and preferences that are turtles all the way down are an impossibility. A class of choices cannot have any members if it is defined such that each member is underlain by a choice of that same class. Likewise for preferences.

And hence I come to the expression sexual preference. As introduced and still generally to-day, it refers to what one sexually prefers; it says nothing about what one meta-prefers or meta-chooses. People said to have sexual preferences are thereby said to choose with those preferences, not to have chosen the preferences themselves. Someone said to have heterosexual preferences is not thus said to have chosen heterosexuality itself, and so too of someone said to have homosexual preferences. And if we deny that sexual preferences can be real because they are not underlain by a choice of sexual orientation, then we must claim that all non-sexual preferences are likewise not real, because it's never turtles-all-the-way-down.

The only people who will be offended by the term sexual preference itself will have confused preferences with meta-preferences — or will be those people who have simply embraced the claim that the term is offensive without much thought as to why it should be so. And a rather large group will not actually be offended, but will rôle-play as if offended, because they observe that this behavior is the practice of their political tribe.

Results about which You've Not Read

17 April 2022

Physics explains color in terms of frequencies — or, equivalently, in terms of wave-lengths — of light. And the colors of substances are explained in terms of what frequencies these substances absorb and what frequencies they radiate or allow to pass.

An object of some color is so because it radiates or allows to pass light of frequencies participating in that color, but absorbs all others. When the object absorbs light of other frequencies, the energy of that light is absorbed. The reason that everyday objects don't then heat-up indefinitely is that they radiate the energy as light, but in the frequencies natural to their substances, rather than simply in the frequencies that were absorbed. A blue sweater converts white light to blue light. Moreover, under stable conditions, substances radiate light in the same set of frequencies. The blue sweater stays blue.

If the Earth did not radiate back into outer-space a significant amount of the light energy in which the Earth is bathed, then it would be dramatically hotter. But, as the surface of the Earth radiates light into the atmosphere, some of that light is absorbed by the atmosphere and then radiated back towards the surface; and, as some of the light radiated by lower parts of the atmosphere is radiated upward, some of it is absorbed by higher parts of the atmosphere and then radiated downward.

What are called greenhouse gasses have their effect by absorbing light energy and then returning a share of it downward, instead of allowing it to escape into outer-space. (Actual greenhouses work by a different principle.)

The theory of anthropogenic global climate change says that release of greenhouse gasses into the atmosphere by human activity causes significant changes to climate by increasing the amount of light energy radiated back downward, instead of being allowed to escape into outer-space.

Climate surely changes, and indeed has warmed and cooled, but that much was true before the first humans appeared, and well before humans released nearly so much of greenhouses gasses since the onset of the Industrial Age. So, if we seem to observe change now, or even warming now, then we want a means of determining whether the human contribution is significant or the change is about what it would be without us.

When the theory of anthropogenic global climate change first came into fashion, its models assumed a linear effect. That is to say that doubling the amount of a greenhouse gas would double the amount of light energy trapped, and so forth. Proper economists were naturally doubtful; we are used to marginal effects beyond some point diminishing. Indeed, the particles of a greenhouse gas would have to be arranged in some remarkable configuration in the sky to have linear effect. We could also imagine remarkable configurations in which marginal effects became immeasurably tiny. It should be no surprise that the linear models failed miserably.

As it happens, the effects of the greenhouse gasses are empirically measurable. Carbon dioxide, methane, and the other greenhouse gasses are like other chemicals, including the dye of that blue sweater that I mentioned. The greenhouse gasses don't simply radiate light energy back towards the surface of the Earth; they radiate it in characteristic frequencies. If you had the resources for strategically placed sensors, then for the last ten, twenty, or thirty years you could have measured the light energy in the relevant frequencies, and could have compared these measurements against the changing levels of the gasses — if you wanted to know.

Many of the various national states have the resources, and every reason to support such a study if its results conform to the theory of anthropogenic global climate change. But the results of a study effecting such measurements on a meaningful scale have not been reported. If that silence is because the results are being kept secret, then plainly they are inconvenient to whomever has kept them secret. If the silence is because such a study has not been undertaken, then plainly that is because the results are expected to be inconvenient.

If you're not autistic, then you recognize the significance for the theory that results have not been reported.

Somnabulism

19 February 2022

[ Three years ago, I posted a version of this entry to Facebook.]

Consciousness is largely a response to surprise. We navigate through life mostly unconscious of what we are doing, but when the unconscious mind encounters something for which it is otherwise unprepared, it invokes the conscious mind.

People are of two sorts about that. For some of them, consciousness is a happier state, and so they are constantly seeking things to make them conscious. For others, it is unpleasant, and they seek always to return to unconsciousness. Perhaps most people fall between these extremes, not always wishing to be conscious nor always unconscious.

Perversely, when people speak or write of raised consciousness, it is often just the opposite; it is the adoption of a set of formulæ that allow one to engage in less conscious thought. And, really, most people who like to style themselves as woke have found a way to sleep still more as they go through life.

Sociopathic Sponsors

9 February 2022
American Sponsors of the Genocide Games: AirBnB, Coca Cola, Intel, Procter & Gamble, Visa

with permission of Common Sense with Paul Jacob