I was working on some graphics code last night and found what I 
think is a problem in the Path hierarchy. 

The original methods collect: and select: tried to send the message
form: to newCollection. The method form: is a Path instance message; it
is not understood by collection.

The original method displayOn: transformation: clippingBox: rule:
fillColor: 
sent the message do: to transformedPath. The message collect: should be
used
instead.

In addition to the code fix, I am suggesting a modification to the
comment
associated with LinearFit. The definitions I got from Ivan Tomek and
Leandro Caniglia were very helpful.

original comment:
"I represent a piece-wise linear approximation to a set of points in the
plane."

revised comment:
"I represent a piecewise-linear approximation to a set of points on a
plane. A piecewise-linear approximation is the best fit of a set of
points by a
continuous series of straight line segments. A square is an example of
a piecewise-liner approximation of a circle."



'From Squeak 2.2 of Sept 23, 1998 on 24 November 1998 at 10:36:51 pm'!
!Path methodsFor: 'enumerating'!
collect: aBlock 
	"Evaluate aBlock for each point in the receiver's collectionOfPoints. 
Answer with a new collection."

	| newCollection |
	newCollection _ collectionOfPoints collect: aBlock.
	^newCollection! !
!Path methodsFor: 'enumerating'!
select: aBlock 
	"Evaluate aBlock for each point in the receiver's collectionOfPoints. 
Answer with a new collection."

	| newCollection |
	newCollection _ collectionOfPoints select: aBlock.
	^newCollection! !
!LinearFit methodsFor: 'displaying'!
displayOn: aDisplayMedium transformation: aTransformation clippingBox:
clipRect rule: anInteger fillColor: aForm 

"Create a new LinearFit and apply aTransformation to the
collectionOfPoints. Display the new LinearFit."
	| newLinearFit transformedPath |
	transformedPath _ aTransformation applyTo: self.
	newLinearFit _ LinearFit new.
	transformedPath collect: [:point | newLinearFit add: point].
	newLinearFit form: self form.
	newLinearFit
		displayOn: aDisplayMedium
		at: 0 @ 0
		clippingBox: clipRect
		rule: anInteger
		fillColor: aForm! !