Squeak-dev August 2001

squeak-dev@lists.squeakfoundation.org

187 participants
488 discussions

Start a nNew thread

Camp Smalltalk Essen day 3
by John M McIntosh 08 Sep '01

08 Sep '01

http://www.smalltalkconsulting.com/html/CSEssen2001_3.html

3 2

[newbie] new look, scrollbars, mouse wheel, diff, searching
by Simon Michael 07 Sep '01

07 Sep '01

new look -------- With a pang of regret for the purist, ultra-mnemonic colored windows (still available of course), I see and embrace the new look. This is really great - very attractive and still usefully color-coded, and more of a subtle 3d look, fewer black outlines. Default flaps have had some nice usability improvements - reorganized, the latest tools added, smaller icons and a text label for each one. And resizing windows & panes now feels much much nicer. What a fine job. I think Jochen's colored scrollbars idea might work well. scrollbars ---------- As usual, dithered around with the scrollbar preferences. Every time I do this, each time with a little less conviction. I have come to like the popup scrollbars; tried putting them on the right; this does not currently work because mousing over to the scrollbar I cross a one-pixel gap and the scrollbar disappears. Capitulated to the default settings. mouse wheel ----------- On my secondary, windows pc, the mousewheel makes scrollbars less important and makes a huge difference in usability. I have a working mousewheel on the linux box but have not yet seen it work in squeak. It would be really nice to have this, should look into it. diff ---- I have one changeset of interest from the old discarded images (some progress bar enhancements). I want to file it in and work on it a bit more, but also to keep things clean, so first I browse the code without actually loading it, via FileList's more.. menu. Problem: diffing the changeset with the current code shows large difference regions apparently due to pretty printing, making it hard to pinpoint the changes that I made back then. Not sure exactly how this comes about. ? question: what's the best way to avoid spurious pretty-print diffs ? Pointers to past discussion/faqs also appreciated. searching --------- Searched the squeak wiki/mailing list/faq for info on the above, no luck. Found that the searchable mailing list archive (not the yahoogroups one) stalls in my browser, though I can squeeze out a few results if I let it run then press stop. Search expression syntax unclear here and apparently nonexistent at yahoogroups, so tried Google. Yes!! They seem to have indexed both the yahoo archive and the swiki, so this should be my new first stop for squeak answers. Must figure out google's host-specifying syntax again, maybe make some custom search forms.

4 8

Re: [Biosqueak] The germ of an idea
by jhgillespie＠ucdavis.edu 06 Sep '01

06 Sep '01

John I have been playing around with bioinformatics and squeak. So far I have a class heirarchy for dna, protein, and coding sequences with lots of useful methods, mostly things like correction formulae, codon usage, base frequencies, etc. In addition, I have a class that parses the Genbank flat file format and can produce sequences from a menu of the documented features. I have used this a bit for my own research, but am now planning to teach a computational genetics course to our biology undergrads using Squeak...so the pressure is on to turn all this into something useful and fun. Right now I can drop sequence morphs onto a playfield and produce things like dot matrix plots and phylogenetic trees, but visually it ain't much. The speed issue hasn't been a problem because I'm not trying to do anything very ambitious. I ported this stuff from my lisp code, where I used calls to C routines (like clustal) to do hard calculations. Perhaps something similar will solve the speed problem with squeak. If any of this sounds useful, I could package it up in its current state. John Gillespie jhgillespie(a)ucdavis.edu "John Tobler" <squeaker(a)diganet.com> wrote: > The last thing I personally need right now is to tangle with a major > non-paying project, so I have decided to start on the design and development > of a Biosqueak initiative. It rubs me the wrong way to see > Bioeveryotherlanguage.org and not to see our beloved Squeak represented. I > would appreciate any and all comments, signs of interest, etc. I will > probably get rolling with implementing some of the simpler bioinformatics > routines, following models already available in Biopython, Bioperl, and > Bioruby. Anyone else who is interested in applying Squeak to bioinformatics > problems is most welcome to join in. > > I am guessing that we will face some formidable obstacles. As Heiko > Schaefer pointed out in a recent post, "... little emphasis has been given > so far on numerical work with squeak." Will someone please correct me if > this assessment is unfair? It looks like some related work is underway by > the Numerics group at the Camp Smalltalk connected with the ESUG conference > in Essen. Hopefully, something approaching the capability of Numeric Python > (NumPy) will magically appear just before we need it for Biosqueak. I am > also sure that bioinformatics processing will fully test Squeak's mettle on > text searching and pattern recognition. Where do we find support for > regular expressions and the like? I anticipate that trying to solve such > real world problems as sequence searching, sequence allignment, and protein > structure prediction will point out areas where we can improve Squeak's > reach and performance. There should be a challenge or two here to keep > hardy pioneers and somewhat unstable test pilots interested. > > Anyway, I intend to get started. This is just a "heads up" that Biosqueak > is out there somewhere on the vast horizon. > > More later, > > John Tobler > squeaker(a)diganet.com > johntobler(a)earthlink.net

20 35

[ENH] StandardFileStream-buffering
by Leandro Caniglia 06 Sep '01

06 Sep '01

from preamble: "Change Set: StandardFileStream-buffering Date: 30 August 2001 Author: Leandro Caniglia Adds dynamic buffering support to StandardFileStream and subclasses. Files can be buffered and unbuffered on the fly. The buffer size of a file can change dynamically. New instances automatically born buffered or unbuffered, depending on a class setting (see StandardFileStream class >> instancesAreBuffered)" !

2 1

[modules] What should be the first step?
by Dan Ingalls 06 Sep '01

06 Sep '01

-- Folks - I'm afraid there is much more about all of this that I don't know than that I do know. That said, perhaps it can be an advantage... I know there are several things we are talking about here, and we need to separate them to come up with clear solutions. What I'd like to do is to propose an operational approach which may help to guide us to getting the "best of both worlds" -- in this case a simple small kernel, but that can support a great group programming engine for large software projects. [If you're in a hurry, skip to ***** Here's what I mean by an operational approach -- think of how we might release the Squeak system: 1. A minimal kernel This would be something like the 240k "tiny" image I made from Squeak a few years ago (had compiler, files, minimal graphics (only enough to put up a transcript), collections, strings and numbers). I would like to go farther with this by using the OS for the transcript, so that all this thing can really do is read in the next package. 2. Basic Graphics This would be the kernel graphics (Form, Color, etc) common to MVC and Morphic. 3. Full Files The kernel might only know about the current directory. This would fill out the rest, along with all the stuff there now that isn't essential. 4. Development system kernel All the browser models 5a. MVC kernel Enough to support MVC applications 5b. Morphic kernel Enough to support simple Morphic applications 6a. MVC development system 6b. Morphic development system You can take it the rest of the way, through network support, network applications, 3D support, 3D applications, scripting system, etc. The important thing, that I doubt any of us disagree with, is that the image is built up in a modular way, so that you could do a headless server or a small squeak for PDAs with no space wasted for the other modules you are not using. Ideally, you could end up with the exact same system whether you built it up from the kernel, or pared it down from a jumbo system -- the modules should be loadable or unloadable in a completely, well, modular manner. *****] What does this say about our architecture for modules? To me it says that what we want to start with in the image is really just the support necessary to receive a new module. This looks like a fairly small requirement -- it could be satisfied by a combination of Lex's ChangeSet proposal and the existing Environments work, with some cleanups and simplifications. I'm curious if people generally agree about this and, if so, if it would be worth summarizing this requirement as a sub-project of the overall effort. A parallel sub-project would be to extend our tools to work with this new architecture. This would seem to be the first step to shoot for, because it would enable... 1. A refactoring of the entire system along the lines above 2. More reliable and consistent sharing of major projects in the community 3. A target image specification for the more serious team development tools which could themselves be added as modules. Do people think this is a reasonable first step? Does anyone want to propose a spec for what needs to be done? - Dan

23 49

Re: [BUG] Float>>tan
by Richard A. O'Keefe 06 Sep '01

06 Sep '01

Ned Konz <ned(a)bike-nomad.com> wrote: "Float halfPi cos" evaluates to a very small number (the reciprocal of the number above, about 1.225e-16 on my system). Should be 0. No, it should NOT be zero. The problem is that halfPi is NOT pi/2. pi Recall that cos(-- + delta) = - sin(delta) approx= - delta. 2 Since pi/2 is a transcendental number, it *cannot* be represented exactly by a floating-point number. There *must* be some error. Float halfPi prints as 1.570796326794897 A better approximation is 1.57079632679489661923 so we see that the error is about 4E-16. I just ran the following C program: #include <math.h> #include <stdio.h> int main(void) { printf("sin: %.17e\n", sin(M_PI_2)); printf("cos: %.17e\n", cos(M_PI_2)); printf("tan: %.17e\n", tan(M_PI_2)); return 0; } The output was sin: 1.00000000000000000e+00 cos: 6.12323399573676604e-17 tan: 1.63312393531953700e+16 NB: this was on a SPARC/Solaris 2.8 system. The trig library uses the "infinite precision PI" technique. What happens if the trig library uses "machine precision PI" instead? Well, to start with, the results get worse and worse and worse as the arguments get bigger. But *then* you might expect Float halfPi cos to be zero. PROVIDED that the "machine precision PI" used by the math library was identical to the value of PI used by Float. Float initializes Pi := 3.lots and lots of digits. so we are dependent on the code that converts floating point numbers from character strings to binary getting its rounding exactly right. Squeak, at least as of 3.0, takes extra care to print numbers well. It does not take quite such care when reading floating point numbers. xxxx.yyyy is computed as (xxxx, an exact integer) asFloat + ( (yyyy, an exact Integer) asFloat / (10 raisedTo: number of digits in yyyy) asFloat ) In a workspace, do this. Type "Float halfPi " PrintIt (Cmd-P, Alt-P, whatever) Insert a "-" between the two spaces you typed in the first step. Select the whole expression "Float halfPi - <number>". PrintIt For me, the final result comes out as -4.44089209850063e-16 That is, subtracting halfPi from "itself" does not give zero! I believe that the cause is roundoff error in Number>>readFromString:. This means that the value of pi (hence also the value of halfPi) used by Float is ever-so-slightly *wrong*. Even if the host math library does use "machine precision pi", the value stored in the HalfPi class variable of Float is NOT THE SAME NUMBER. For the last 50 years, savvy programmers who have wanted a good approximation of pi in the programs have asked the math library to compute it, e.g. HALFPI = 2.0*ATAN(1.0) in Fortran. Decimal/binary conversion errors are not the least of the reasons for doing this.

2 1

[ENH]Html table (second version)
by Karl Ramberg 04 Sep '01

04 Sep '01

I'm still torturing my self, but I begin to see the light :-) -I solved the nesting of the tables! -links within tables work These were the really hard parts to figure out. Left to do is paying attention to attributes like table color border widths etc. Should be easy;-) Enjoy, Karl

8 22

[ENH] Mouse Click Focus Policy option.
by sps2000＠mail.com 04 Sep '01

04 Sep '01

from preamble: "Change Set: spsFocusPolicy Date: 30 August 2001 Author: Steven Swerling This change set adds a preference called ""mouseClickFocusPolicy"" in the morphic tab of the preferences window. If unchecked, behavior is identical to the standard focus policy -- the pane that the mouse is over gets keyboard focus. If checked, the user must explicitly click in a pane to set the focus on that pane -- the location of the mouse does not effect where the keyboard focus goes. I have been using this focus policy for awhile now, and it''s solid -- for me. There are bound to be little snags, which I will try to fix as they are reported. "!

6 5

The VM is in the Swiki
by Andres Valloud 04 Sep '01

04 Sep '01

Hi. The VM I used to release SWT 0.6 is now in the Swiki. Andres.

3 9

really silly question
by John Hinsley 04 Sep '01

04 Sep '01

Given two arrays of the same size filled with numbers, can someone give me a code snippet that will show me how to add the numbers at the same index to produce a third array? So that firstArray:= #(1 2 3 4) secondArray:= #(5 6 1 2) will result in a thirdArray (6 8 4 6) Cheers John (hangs head in shame....) -- Can't cope anymore? Desperate for help? Join the 12 step program for those who yearn to give up Microsoft: http://home.earthlink.net/~penguinrox/index.html

10 12

Jump to page: