On Sun, 27 Apr 2003 14:25, Kim Rose wrote:
-- Greetings -
Viewpoints Research is working on updating the Squeakland.org website. As part of this project, we wish to point to a variety of schools, groups, community centers, etc. using Squeak (the Etoy-tile scripting component) and include interesting project examples.
I have added a graphical angle watcher to Randy Caton's Pendulum. It draws a sinusoidal graph in real time of the simulated pendulum's angle as it swings to and fro. I have also put some annotations on it. The plotter script is not synchronous with the pendulum script, so by changing the sample rate of the plotter one can demonstrate the effect of too slow a rate destroys the effective measurement of the waveform. It's quite pretty, though I say so myself, and my 13 year old son was somewhat impressed.
It's here:-
http://berty.dyndns.org/CSpendulum.pr
While doing this I noticed that there's a minor bug in the drawing of the graph lines on a Playfield. The horizontal lines appear to be drawn relative to the top of the Playfield, whereas the 'y' coordinate of an object is measured with respect to the bottom of the Playfield. This means that unless the height of the Playfield is an exact multiple of the graticule size then the actual 'y' co-ordinate and its values as read off the graph do not correspond. This is demonstrated with a simple project here:-
http://berty.dyndns.org/GraphBug.pr
The red plotted line should go through the corners of the green squares precisely.
HTH
-- C. S.
Hi, Christopher - Thanks so much...but when I loaded this url all I got was a blank Squeak project... hmmmmm??? Kim
At 12:07 AM +1200 4/28/03, Christopher Sawtell wrote:
On Sun, 27 Apr 2003 14:25, Kim Rose wrote:
-- Greetings -
Viewpoints Research is working on updating the Squeakland.org website. As part of this project, we wish to point to a variety of schools, groups, community centers, etc. using Squeak (the Etoy-tile scripting component) and include interesting project examples.
I have added a graphical angle watcher to Randy Caton's Pendulum. It draws a sinusoidal graph in real time of the simulated pendulum's angle as it swings to and fro. I have also put some annotations on it. The plotter script is not synchronous with the pendulum script, so by changing the sample rate of the plotter one can demonstrate the effect of too slow a rate destroys the effective measurement of the waveform. It's quite pretty, though I say so myself, and my 13 year old son was somewhat impressed.
It's here:-
http://berty.dyndns.org/CSpendulum.pr
While doing this I noticed that there's a minor bug in the drawing of the graph lines on a Playfield. The horizontal lines appear to be drawn relative to the top of the Playfield, whereas the 'y' coordinate of an object is measured with respect to the bottom of the Playfield. This means that unless the height of the Playfield is an exact multiple of the graticule size then the actual 'y' co-ordinate and its values as read off the graph do not correspond. This is demonstrated with a simple project here:-
http://berty.dyndns.org/GraphBug.pr
The red plotted line should go through the corners of the green squares precisely.
HTH
-- C. S.
--
On Mon, 28 Apr 2003 05:24, Kim Rose wrote:
Hi, Christopher - Thanks so much...but when I loaded this url all I got was a blank Squeak project... hmmmmm??? Kim
Dear O dear,
I've just checked, the full file is definitely there. [chris@berty chris]$ ls -l /var/www/html/CSpendulum.pr -rw-r--r-- 1 chris users 206881 Apr 27 23:19 /var/www/html/CSpendulum.pr
Here are the md5sums so you can check that there have not been any trasmission errors:- 2296d55657a529bf754751d084ba419a /var/www/html/CSpendulum.pr 01fef3280bd77e6adb99cb9842f81743 /var/www/html/GraphBug.pr
If that's correct, it looks as if we have been caught out by incompatible interpreters or something else to do with using moving target software. I upgraded the image and changes files only a couple of days ago. I think I'm up to date, but I'm not sure?
Here are the version details of the Squeak interpreter I'm using.
chris@liberty chris $ squeak -version 3.4-1 #1 XShm Thu Mar 13 22:24:42 NZDT 2003 gcc 3.2.1 Squeak3.4 of 1 March 2003 [latest update: #5170] Linux liberty.localnet 2.4.20-xfs_pre6 #1 Sat Mar 8 20:42:23 NZDT 2003 i686 Pentium II (Deschutes) GenuineIntel GNU/Linux default plugin location: /usr/local/lib/squeak/3.4-1/*.so
At 12:07 AM +1200 4/28/03, Christopher Sawtell wrote:
On Sun, 27 Apr 2003 14:25, Kim Rose wrote:
-- Greetings -
Viewpoints Research is working on updating the Squeakland.org website. As part of this project, we wish to point to a variety of schools, groups, community centers, etc. using Squeak (the Etoy-tile scripting component) and include interesting project examples.
I have added a graphical angle watcher to Randy Caton's Pendulum. It draws a sinusoidal graph in real time of the simulated pendulum's angle as it swings to and fro. I have also put some annotations on it. The plotter script is not synchronous with the pendulum script, so by changing the sample rate of the plotter one can demonstrate the effect of too slow a rate destroys the effective measurement of the waveform. It's quite pretty, though I say so myself, and my 13 year old son was somewhat impressed.
It's here:-
http://berty.dyndns.org/CSpendulum.pr
While doing this I noticed that there's a minor bug in the drawing of the graph lines on a Playfield. The horizontal lines appear to be drawn relative to the top of the Playfield, whereas the 'y' coordinate of an object is measured with respect to the bottom of the Playfield. This means that unless the height of the Playfield is an exact multiple of the graticule size then the actual 'y' co-ordinate and its values as read off the graph do not correspond. This is demonstrated with a simple project here:-
http://berty.dyndns.org/GraphBug.pr
The red plotted line should go through the corners of the green squares precisely.
HTH
-- C. S.
squeakland@lists.squeakfoundation.org
-
csawtell＠paradise.net.nz -
Kim.Rose＠viewpointsresearch.org