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<TITLE>Re: Pendulum</TITLE>
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<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=130131023-15042003>I am
not able to bring up the project that Alan broadcast. I recently installed
Squeakland 3.2.4913 (latest update #152)</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=130131023-15042003></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=130131023-15042003>I am
getting -</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=130131023-15042003>MessageNotUnderstood: default - An error has occurred;
you should probably just hit 'abandon'.</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=130131023-15042003></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=130131023-15042003>Any
suggestions?</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=130131023-15042003></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=130131023-15042003>Thank
you,</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=130131023-15042003>Vince
Huston</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=130131023-15042003>Dallas</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=130131023-15042003></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=130131023-15042003><FONT
size=2>
<P>here insert explanation of what you were doing, suspect changes you've</P>
<P>made and so forth.</P>
<P>I am trying to open the project Alan Kay just sent out -</P>
<P>PendulumTaTum.001.pr</P>
<P>15 April 2003 6:27:11 pm</P>
<P>VM: Win32 - Squeak3.2gamma of 12 January 2002 [latest update: #4879]</P>
<P>Image: Squeakland 3.2.4913 [latest update: #152]</P>
<P>TTFontDescription class(Object)>>doesNotUnderstand:</P>
<P>Receiver: TTFontDescription</P>
<P>Arguments and temporary variables: </P>
<P>t1: a Message with selector: #default and arguments: #()</P>
<P>Receiver's instance variables: </P>
<P>superclass: Object</P>
<P>methodDict: a MethodDictionary(#deepCopy->a CompiledMethod (2064)</P>
<P>#name->a Comp...etc...</P>
<P>format: 162</P>
<P>instanceVariables: #('glyphTable' 'glyphs' 'kernPairs' 'copyright'</P>
<P>'familyName'...etc...</P>
<P>organization: ('accessing' name size)</P>
<P>('copying' deepCopy objectForDataStream: ...etc...</P>
<P>subclasses: nil</P>
<P>name: #TTFontDescription</P>
<P>classPool: a Dictionary(#Default->nil #Descriptions->a Set() )</P>
<P>sharedPools: nil</P>
<P>environment: a SystemDictionary(lots of globals)</P>
<P>category: nil</P>
<P>TTCFont class>>initialize</P>
<P>Receiver: TTCFont</P>
<P>Arguments and temporary variables: </P>
<P>tt: nil</P>
<P>Receiver's instance variables: </P>
<P>superclass: AbstractFont</P>
<P>methodDict: a MethodDictionary(#ascent->a CompiledMethod (1064)</P>
<P>#baseKern->a Co...etc...</P>
<P>format: 138</P>
<P>instanceVariables: #('ttcDescription' 'name' 'pixelSize'</P>
<P>'foregroundColor')</P>
<P>organization: ('as yet unclassified' ascent baseKern basicPixelSize:</P>
<P>computeTra...etc...</P>
<P>subclasses: nil</P>
<P>name: #TTCFont</P>
<P>classPool: nil</P>
<P>sharedPools: nil</P>
<P>environment: a SystemDictionary(lots of globals)</P>
<P>category: nil</P>
<P>UndefinedObject>>DoIt</P>
<P>Receiver: nil</P>
<P>Arguments and temporary variables: </P>
<P>Receiver's instance variables: </P>
<P>nil</P>
<P>Compiler>>evaluate:in:to:notifying:ifFail:</P>
<P>Receiver: a Compiler</P>
<P>Arguments and temporary variables: </P>
<P>t1: 'TTCFont initialize'</P>
<P>t2: nil</P>
<P>t3: nil</P>
<P>t4: nil</P>
<P>t5: [] in Compiler class>>evaluate:for:notifying:logged:</P>
<P>t6: DoIt</P>
<P>^ TTCFont initialize</P>
<P>t7: a CompiledMethod (3467)</P>
<P>t8: nil</P>
<P>Receiver's instance variables: </P>
<P>sourceStream: a ReadStream</P>
<P>requestor: nil</P>
<P>class: UndefinedObject</P>
<P>context: nil</P>
<P>--- The rest of the stack ---</P>
<P>Compiler class>>evaluate:for:notifying:logged:</P>
<P>Compiler class>>evaluate:for:logged:</P>
<P>Compiler class>>evaluate:logged:</P>
<P>[] in RWBinaryOrTextStream(PositionableStream)>>fileInAnnouncing:</P>
<P>BlockContext>>on:do:</P>
<P>[] in RWBinaryOrTextStream(PositionableStream)>>fileInAnnouncing:</P>
<P>ProgressInitiationException>>sendNotificationsTo:</P>
<P>[] in ComplexProgressIndicator>>withProgressDo:</P>
<P>ProgressInitiationException(Exception)>>handlerAction</P>
<P>ProgressInitiationException(Exception)>>signal</P>
<P>ProgressInitiationException>>display:at:from:to:during:</P>
<P>ProgressInitiationException class>>display:at:from:to:during:</P>
<P>String>>displayProgressAt:from:to:during:</P>
<P>RWBinaryOrTextStream(PositionableStream)>>fileInAnnouncing:</P>
<P>RWBinaryOrTextStream(PositionableStream)>>fileIn</P>
<P>RWBinaryOrTextStream(ReadWriteStream)>>fileInObjectAndCode</P>
<P>[] in ProjectLoading</P>
<P>class>>openName:stream:fromDirectory:withProjectView:</P>
<P>BlockContext>>ensure:</P>
<P>ProjectLoading
class>>openName:stream:fromDirectory:withProjectView:</P>
<P>[] in ProjectLoading class>>openFromDirectory:andFileName:</P>
<P>BlockContext>>on:do:</P>
<P>[] in ComplexProgressIndicator>>withProgressDo:</P>
<P>BlockContext>>on:do:</P>
<P>ComplexProgressIndicator>>withProgressDo:</P>
<P>ProjectLoading class>>openFromDirectory:andFileName:</P>
<P>TheWorldMenu>>loadProject</P>
<P>TheWorldMenu>>doMenuItem:with:</P>
<P>[] in MenuItemMorph>>invokeWithEvent:</P>
<P>BlockContext>>ensure:</P>
<P>CursorWithMask(Cursor)>>showWhile:</P>
<P>MenuItemMorph>>invokeWithEvent:</P>
<P>MenuItemMorph>>mouseUp:</P>
<P>MenuItemMorph>>handleMouseUp:</P>
<P>MouseButtonEvent>>sentTo:</P>
<P>MenuItemMorph(Morph)>>handleEvent:</P>
<P>MorphicEventDispatcher>>dispatchDefault:with:</P>
<P>MorphicEventDispatcher>>dispatchEvent:with:</P>
<P>MenuItemMorph(Morph)>>processEvent:using:</P>
<P>MorphicEventDispatcher>>dispatchDefault:with:</P>
<P>MorphicEventDispatcher>>dispatchEvent:with:</P>
<P>MenuMorph(Morph)>>processEvent:using:</P>
<P>MenuMorph(Morph)>>processEvent:</P>
<P>MenuMorph>>handleFocusEvent:</P>
<P>[] in HandMorph>>sendFocusEvent:to:clear:</P>
<P>PasteUpMorph>>becomeActiveDuring:</P>
<P>HandMorph>>sendFocusEvent:to:clear:</P>
<P>HandMorph>>sendEvent:focus:clear:</P>
<P>HandMorph>>sendMouseEvent:</P>
<P>HandMorph>>handleEvent:</P>
<P>HandMorph>>processEvents</P>
<P>[] in WorldState>>doOneCycleNowFor:</P>
<P>Array(SequenceableCollection)>>do:</P>
<P>WorldState>>handsDo:</P>
<P>...etc...</P></FONT></SPAN></FONT></DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Alan Kay
[mailto:Alan.Kay@squeakland.org]<BR><B>Sent:</B> Tuesday, April 15, 2003 6:02
PM<BR><B>To:</B> squeakland@squeakland.org<BR><B>Cc:</B> Andreas
Raab<BR><B>Subject:</B> Re: Pendulum<BR><BR></FONT></DIV>
<DIV>What's the model behind the "movin' pictures"?</DIV>
<DIV><BR></DIV>
<DIV>The simple frame by frame animation has a very weak and almost
nonexistent model.</DIV>
<DIV><BR></DIV>
<DIV>But, as you've seen from our demos and the DVD documentary, even 5th
graders can figure out the two line script that represents an excellent 2nd
order differential equation of the (almost) constant accelleration of gravity
near the surface of the earth. This is what drives a real pendulum.</DIV>
<DIV><BR></DIV>
<DIV>Now you just have to "see" how the downwards and sideways forces change
with the position of the pendulum and you can easily make a real model of
it.</DIV>
<DIV><BR></DIV>
<DIV>Enclosed is a project that has noticed that the rotational force is
proportional to the sine of the angle of the pendulum. But, there is a nice
way to bypass trig completely by directly "weighing" the forces exerted by
gravity at different angles ... heh heh ...</DIV>
<DIV><BR></DIV>
<DIV>Cheers,</DIV>
<DIV><BR></DIV>
<DIV>Alan</DIV>
<DIV><BR></DIV>
<DIV>--</DIV>
<DIV><BR></DIV>
<DIV>At 3:23 PM -0400 4/15/03, Brucestro@aol.com wrote:</DIV>
<BLOCKQUOTE cite="" type="cite"><FONT
face="Times New Roman">Andreas/Phil,<BR><BR>Wouldn't another possilble
approach be to create a series of pictures showing all the possible
positions of the pendulum and then control it as one would control a
cartoon/movie? (Phil - There are examples of this technique at
squeakland.org under the eToys link.) Another option that comes to
mind is to stack each of these pictures on top of each other and move them
front to back as required. Andreas, I'm new to Squeak -- would these
ideas work, or am I on the wrong track?<BR><BR>Thanks,<BR>Bruce
Strothenke<BR>Teachers College Columbia University</FONT></BLOCKQUOTE>
<DIV><BR></DIV>
<DIV><BR></DIV><X-SIGSEP><PRE>--
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