Calliope Sounds

A comment on "So which IDE is the best and why?"

My comment to So which IDE is the best and why? Im a beginner and only know of a few I prefer Eclipse : java:

An IDE gives you three very useful tools. Code editing. Code navigation. And code debugging. Each of the commenters, I am sure, have different needs and styles of these tools. You will also.

All the IDEs tend to have very aggressive code editing help. This is great when you are working with new packages but the help gets tiresome as your packages familiarity increases and yet the IDE continues to make suggestions when you know full well what you want. Code navigation in modern IDEs is a godsend. To be able to move easily between classes, up and down the inheritance hierarchy, and around usages. Code debugging is less about the source and more about the data and the threads. The better the tools are at showing data structures -- the plural is important! -- and visually connecting threads w/ stack traces the easier your job becomes.

I have not answered your question because there is no answer. We shape our tools and our tools shape us. It almost does not matter which you pick -- Eclipse, IntelliJ, NetBeans, Emacs w/ JDEE, Vim w/ JDE, .... What matters is that using the IDE becomes second nature.

And don't fool yourself that you will fix the IDE's problems. You don't have that much free time.

Code now on GitHub

I have started to move and/or clone my code to GitHub -- like everyone else....

Calliope Sounds has an ISSN

I work for a small publisher intermediary and while working with our data recently I needed an testing ISSN. It got me thinking about the work involved with getting an ISSN for my blog -- an online serial publication. There is one form to complete and that is then mailed to the Library of Congress along with the "front page" of the publication. I did this about two weeks ago and today the Library of Congress, United States, ISSN Center delivered my new ISSN. In all its glory, here it is

ISSN 2165-0861

Using reflection for command line option parsing

Over the last few days I have needed a few command line tools -- mostly for data cleanup. I got tired of manually parsing command line arguments. I wanted something more automated. My first thought was to design a data-structure that expressed the command lines arguments then write an interpreter that would parse the arguments with its guidance. I spent an hour doing this only to realize that preparing the data-structure was almost as much work as manual parsing. Then I remembered that Ant has a simple facility that uses reflection to execute a task expressed in XML against an object. This is what I wanted. So, for example, the command line tool

java ... Sum --multiplier 25 --verbose 1 2 3 4

would be implemented as

public class Sum implements Runnable {

   public void setVerbose() {
      this.verbose = true;
   }

   public void setMultiplier( Long multiplier ) {
      this.multiplier = multiplier;
   }

   public void addPositional( Long number ) {
      this.numbers.add(number);
   }

   public void run() {
      long sum = 0;
      for ( Number number : this.numbers } {
         if ( verbose ) {
            System.out.printf("%d + %d= %d\n", 
               sum, 
               number.longValue(), 
               sum + number.longValue() );
         }
         sum += number.longValue();
      }
      if ( this.multiplier != null ) {
         if ( verbose ) { ... }
         sum *= multiplier;
      }
      System.out.println(sum);
  }

  ...

}

The magic, of course, is reflection. The reflection-based parser sees "--verbose" and matches it against setVerbose(), "--multiplier" matches against setMultiplier() and that it takes one numeric option. The remaining positional arguments are passed to addPositional() as numbers. Once parsed run() is called. The ReflectiveCommandLineParser is used to handle the magic within the main()

   public static void main( String[] args ) {
      Sum sum = new Sum();
      ReflectiveCommandLineParser.run(sum,args);
   }

See ListFiles implementation for another example.

How MySql loads result sets

I was having a devil of a time yesterday with the simple task of using a Java program to copy records as objects from one MySql database to another [1]. I kept running out of memory. While the root problem had to do with creating 2M objects in memory it did lead to a better understanding of how MySql loads result sets. In short, it loads the whole result set into memory in one shot. So, if you have 1M records at 1K each in the result set you will need at least 1G of memory to hold them. If you then build 1M objects from these records you will need an additional 1M * object size of memory. In other words, a lot of memory.

You can have the MySql JDBC driver "stream" the result set, however. That is, read the records row by row from the database. It is less efficient for the driver -- multiple trips back and forth between the server -- but doing so requires far less memory. You can turn on streaming at the statement level or at the datasource level.

Statement Level
To turn on streaming at the statement level you need to use a set of common JDBC settings that, when used together, inform the driver to stream. When you create or prepare a statement you must define how the result will be used and what is the fetch size. For example,

Statement statement = connection.createStatement(
 ResultSet.TYPE_FORWARD_ONLY, 
 ResultSet.CONCUR_READ_ONLY);
statement.setFetchSize(Integer.MIN_VALUE);

and

PreparedStatement statement = connection.prepareStatement(
 "select ... from ... where ...",
 ResultSet.TYPE_FORWARD_ONLY,
 ResultSet.CONCUR_UPDATABLE);
statement.setFetchSize(Integer.MIN_VALUE);

For more information see section Result Set in JDBC API Implementation Notes.

DataSource Level
To turn on streaming at the statement level you need to add a property to the JDBC uri. For example, Integer. MIN_VALUE is -2^31 and so use

jdbc:mysql://localhost/?defaultFetchSize=-2147483648

For more information see Driver/Datasource Class Names, URL Syntax and Configuration Properties for Connector/J.

[1] I could not use the MySql tools for dumping and loading the table data because I used an auto_increment column in one of the related tables, the target database was active with data, and so could not reset the target's auto_increment column to an appropriate value.

Response to "EasyMX - An alternative to JMX"

A response to EasyMX - An alternative to JMX | Javalobby:

An advantages to using JMX is that the JMX client gets to the service via a different network path than the service's users. When the service is running well the path taken does not matter much. It is often the case, however, that the main service path becomes inaccessible under adverse conditions. Your HTTP requests are not being serviced before timeouts kick in, for example. And, consequently, your monitoring is also inaccessible. JMX clients use RMI or direct socket pathways to connect to the service and so the JMX client can continue to monitor and manage the service.

As Mr Fisher says (first comment to the posting), JMX is one of the "golden parts" of the Java ecosystem. (JBose was built on top of it.) Current JMX coding practices are more sophisticated than in the early days. The "MBean" and "MXBean" interface suffix continue to support quick and dirty monitoring and publishing. And for those with lots of monitoring and management touchpoints we too use sophisticated Java annotations processing to turn existing code into touchpoints.

Revised log levels proposal

@jbarnette: Revised log levels proposal: "fyi," "wtf," and "omg."

In praise of gnuplot's dumb terminal support

I have to say, again, I find gnuplot's dumb terminal support is so useful when you are at the command line and need to see a plot of some data. The plot is very rough but this is usually enough to give you enough insight into the data as to whether or not to continue to exploring it. The script I am using now is

#!/bin/bash

function show_usage {
 echo \
  usage: $(basename $0) \
  [-x label] \
  [-y label] \
  [-t title] \
  [-s width:height] \
  [-f time-format-strftime] \
  timeseries-input ...
}

function swap {
 echo $2 $1
}

function parse_size {
 W=$(expr $1 : "\\([0-9]*\\):[0-9]*")
 H=$(expr $1 : "[0-9]*:\\([0-9]*\\)")
 echo "$W $H"
}

TIMEFMT="%Y-%m-%dT%H:%M:%S"
XLABEL="Time"
YLABEL="Units"
TITLE="Timeseries"
SIZE=$(swap $(stty size))

while getopts "x:y:t:f:s:h" opt
do
 case $opt in
  x) XLABEL=$OPTARG ;;
  y) YLABEL=$OPTARG ;;
  t) TITLE=$OPTARG ;;
  f) TIMEFMT=$OPTARG ;;
  s) SIZE=$(parse_size $OPTARG) ;;
  h) show_usage ; exit 0 ;;
  *) show_usage ; exit 1 ;;
 esac
done
shift $(expr $OPTIND - 1)

for INPUT in $*
do
 if [ "$INPUT" = "-" ]
 then
  INPUT=$(mktemp /tmp/timeplot.XXXXXXXXXX)
  cat > $INPUT
 fi

 gnuplot <<EOH
  set terminal dumb $SIZE
  set autoscale
  set xdata time
  set timefmt "$TIMEFMT"
  set xlabel "$XLABEL"
  set ylabel "$YLABEL"
  set title "$TITLE"
  plot "$INPUT" using 1:2 with lines
EOH
done

# END

For example, if the data in /tmp/data is

then this can be quickly plotted using

timeplot -f %Y /tmp/data

and get

Under glass they can have it all

I have been deeply troubled more recently by having been given a name to what I/we see happening. Our world's experiences are rapidly being shared "under glass" [1]. Be it phones, tablets, desktops, etc. We photograph our children and show the image under glass and not on paper. We hear a poet not in person but from under glass. The Call of Duty gets adrenaline rushing with only the risk of spilling your soda. Ever more of our worlds experiences are under glass. For kids under glass has become their first experience. For some it will be there only experience. You can look and listen but you can not touch. Experience as diorama. The outside framed. Technology advances and so we might just be at a low point in the development of experience+technology. I don't think this is the case. The soma of instant gratification to even the artificial is too strong a force. Umberto Eco talked about American's allure of hyper-reality. Under glass they can have it all.

[1] A Brief Rant on the Future of Interaction Design

Genevieve Bell

Enjoyed Genevieve Bell's presentation about the lives of data: Genevieve Bell's presentation on bordom:

An ode to Dennis Ritchie

An ode to Dennis Ritchie, of C and Unix fame, who died this week. A Unix command that echos the input characters and swaps the foreground and background colors after every 7th line break

#include <stdlib.h>
#include <stdio.h>
void main() {
  int l = 0;
  int c = 0;
  char** f = malloc(sizeof (char*) * 2);
  f[0] = "\033[0;7m";
  f[1] = "\033[7;0m";
  while ( ( c = getchar() ) != EOF ) {
    if ( c == '\n' ) {
      if ( l % 7 == 0 ) {
        printf(f[l%2]);
      }
      l++;
    }
    putchar(c);
  }
  printf("\033[0m");
}

Unfortunately, with all candor, I am glad I don't code in C anymore.

Re: Cloud-Powered Facial Recognition Is Terrifying

In the posting Cloud-Powered Facial Recognition Is Terrifying a commentator noted that at 98% accuracy the facial recognition software would have 200,000 false positives per year for a typical airport. This is an inconvenience. The terrifying part is that you also have to consider the false negatives. Assume (for ease of calculation) that 1% of the population are terrorists. Within a population of 1,000,000 there are 10,000 terrorists. Within that, 2% of terrorists will not be recognized and 200 of them will be allowed to fly. Boom! It really doesn't matter what the real ratio of terrorists to non-terrorists is. What matters is the human costs of a false negative.

Comment on David Ascher's posting "Am I reading these trends right?"

My comment on David Ascher's posting is Am I reading these trends right?

What if the big 5 are perceived as "magazines." That is, if you look at what the big 5 are doing it is little more than gaining an audience by offering remarkable content. When you buy a magazine you don't think about the conveyance, the staples or glue bound, high-resolution images on paper. The same will happen with tablets and other hardware. You pickup the "Vogue tablet" to read its curated content. And "Maker tablet" to read its. I am sure there will be national and international standards shaping a convergence of software and hardware as these "magazines" accumulate. Just as there is, today, an international standard for shower-curtain rings.

What if the singularity is not centered on intelligence but instead on population

I attending Verner Vinge's lecture at URI on Tuesday night. He talked mostly about the art and mechanics of writing science fiction and a little about the "singularity." Like Ray Kurzweil, he sees the singularity as the appearance of super-human intelligence. He is a little more open, it seems to me, as to whether this is embodied within humans or wholly non-human. (As a side note, I like Jessie Schell's definition where the singularity is the point at which the future is unpredictable because the future changes come, to human perception, instantaneously.) My question to Vinge was

"What if the singularity is not centered on intelligence but instead on population. Nano beings that's population grows (near instantaneously) to consume all the planets resources."

Unfortunately, it was not one picked by the moderator and so I will have to answer this myself.

Act locally

The following is a comment made within Facebook's walls that I want to share further.

At heart I am a socialist. I live in the USA but was raised in the UK. I firmly believe that it is our government's only obligation to protect its citizens, culture, and environment. To that end, education should always be available to all. Health care should be available to all. A functioning natural environment should be available to all. A robust and varied culture should be available to all. Everything else is a means to these ends.

But this is not the country we live in. Since the 1970's we have had a government ever more focused on "job creation". And this has been expressed time and time again as enabling corporate growth and capital gains growth. We have have 40 years of this messaging. That is 2 generations. The message is firmly planted in the citizen's psyche. The problem is that this is a lie. And worse, a bold faced lie if you just open your eyes and look beyond our territorial boarders. We are a insular people.

Since the height of US world dominance in the 1950s the US population has doubled. We had 150M citizens then and now we have 300M. Our focus has also changed from local solutions/problems to national solutions/problems. (We do, after all, have a national, homogenizing media.) A solution for 300M people is more than twice as difficult than one for 150M people. And, generally, whatever the solution is it is likely wrong. As Henry David Thoreau (kind'a) said "why do I care about the weather in Texas when I live in Rhode Island."

So, this is a long aside to my belief that we should not focus on solving our local problem at the national level. We can solve them locally for RI. There is no reason why RI can not have universal health care. There is no reason why RI can not have free higher education. There is no reason why RI can not give economic aid. RI has to make sure that this is all accumulated in an equitable way to past, present, and future citizens. But I feel this can be done.

To do it, however, we have to take action.

Video-game studies have serious flaws : Nature News

Video-game studies have serious flaws : Nature News is a good review of of the studies of video game effects on children & young adults.

"Boot and his colleagues say that none of the studies they examined avoided all of the methodological pitfalls, and that this raises doubts about the cumulative evidence that action video games enhance cognition. Boot stresses that the studies' claims are not necessarily wrong — but although the available evidence is promising, it is not compelling enough for researchers to draw strong conclusions legitimately."

Programming options for kids – Boing Boing

Here is my comment Programming options for kids – Boing Boing

To some degree the language does not matter. What matters is that the kid is ready for the abstract thinking required for programming and that he or she wants to program. My son, then 10, spent a week programming w/ Scratch. He enjoyed it but then abandoned it because there was no relationship between his life and what he could do within Scratch. If Scratch connected to the outside world (think Maker and Instructables here) he would have continued further (I think). Kids think of programming like drawing a specific picture or building a play structure. I do it now and I am done. For them, it is not an intellectual journey.

Basecamp and linking to Google Docs content

Basecamp does not have a means of listing links to external content. It does allow for uploading and so you can use this facility to have links to external content. I needed this for a small project that uses Basecamp to coordinate activities and Google Docs to hold content. The "link" to external content is encoded in an HTML document. For example,

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
  <head>
    <title>TITLE</title>
    <script>
      var url = "URL";
    </script>
  </head>
  <body onload="window.location.href=url">
    <p>Automatically redirecting the browser to <script>document.write("<a href=\""+url+"\">"+xml_encode(url)+"</a>")</script>.</p>
  </body>
</html>

Replace TITLE with the title of the content and URL with the URL to the content. (Don't forget to XML encode any HTML entities in the title and JavaScript escape any special characters in the URL.) Save this document to a file and then upload this file to Basecamp. When a user selects the uploaded file in Basecamp the user's browser will be redirected to the content at the URL. A lighter weight version of the HTML content is simply

<body onload="window.location.href='URL'"/>

Why do many programmers insist that non-graphical tools are superior to GUIs?

The Quora question is Why do many programmers insist that non-graphical tools are superior to GUIs? and the simple answer is that programmers work extensively with the names of things -- machines, directories, files, packages, classes, methods, functions, variables, language statements, fields, tables, actions, commands, etc. And so any tool that that lets me use names as navigation to the named thing or things related to the named thing is preferable.

Designing command-line interfaces

I like the posting Designing command-line interfaces. Being a CLI type developer I have implemented most CLIs with Anders' recommendations in my tools. Points I would like to emphases are

1) For long running commands make them verbose by default. For short running commands, like mv and cp, make them quiet by default.

2) While I like autoconf's use of "no" to turn off an option, eg --no-foos, and "=" to provide an option's optional value, eg --debug on default port or --debug=port for a specific port, it is not used enough elsewhere and so is too unexpected. Don't use them.

3) Always use a non-zero exit if you find an unknown option or an unknown positional parameter.

4) Use one-dash for one-letter options and two-dashes for multiple-letter options. Eg, -v and --version, -h and --help. There are many libraries available that help parse options. I tend to only use two-dash options and so hand code the parsing.

5) If you don't use one-dash options make sure to reject all positional parameters that start with a dash as this is mostly a user error. If you want to allow positional parameters that start with a dash then use the common "--" parameter to indicate that the remaining parameters are all positional parameters.

6) An option can have multiple arguments. For example, --database url user password.

7) Always have the options --help/-h, --version/-v, --quiet/-q, and --verbose.

8) If a command can run without options make sure the command's results are harmless. Nothing worse than incorrectly using a command and having it destroy data.

I will, perhaps, add other points for emphases at a later date. For now, do read Anders' posting.