Beginners March 2019

beginners@lists.squeakfoundation.org

7 participants
4 discussions

Squeak Learn Programing with Robots
by Robert Kuropkat 24 Apr '19

24 Apr '19

Is there an updated Ready.image file (the one that goes with the book) that works with the latest Squeak? I'm looking to teach a class and wanted to use this book, but at first blush, the image does not seem to work with Squeak 5.2 (on Linux at least). Robert Kuropkat

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Translating ChronologyConstants
by Christian Kellermann 24 Mar '19

24 Mar '19

Dear List, for localizing an Application I would like to translate the constants in the Chronology-Core. What's the best way to do this? I file my changes for my application in a Monticello package. I could just overwrite the definitions with my own, but I would love to do this in a less destructive way. Any ideas? Thanks! Christian -- May you be peaceful, may you live in safety, may you be free from suffering, and may you live with ease.

2 2

Windows image has system time delay
by Benoit St-Jean 12 Mar '19

12 Mar '19

Is there anyone else aware of this problem ?? https://github.com/pharo-project/pharo/issues/2792#issuecomment-471902972 -- ----------------- Benoît St-Jean Yahoo! Messenger: bstjean Twitter: @BenLeChialeux Pinterest: benoitstjean Instagram: Chef_Benito IRC: lamneth GitHub: bstjean Blogue: endormitoire.wordpress.com "A standpoint is an intellectual horizon of radius zero". (A. Einstein)

1 0

orientation of polygons
by Ralph Boland 10 Mar '19

10 Mar '19

In Squeak should the vertices of a polygon be listed in clockwise or counter-clockwise order? Note that I am not concerned about which is best, just which Squeak uses. I need to make a choice in order to compute the areas of polygons and the algorithms that do this negate the area if you process the vertices in the opposite order. Note that it is not sufficient to just take the absolute value of the result of computing the area because I have to deal with a polygon being cut into two parts by a line seqment (a chord). Which of the two parts of the polygon I want the area of is determined by the ordering of the vertices of the polygon and also the ordering of the the vertices of the line segment. Reversing the ordering of the vertices of either switches the subpolygon chosen. Reversing both has no affect because the two switches cancel. So I have to make a choice and live with it. I want my choice to be consistent with any similar choice made in Squeak code. If none of the Squeak code depends on polygon vertices ordering then I would like to hear opinions on the matter so at least I can a decision that is at least better then arbitrary. Note that mathematics doesn't seem to help much here. The shoelace algorithm for computing the area of a polygon and Green's theorem both use a counter-clockwise orientation. However simple integration to determine the area under a curve implies a clockwise orientation (adding areas under each edge of the polygon when going left to right and subtracting when going right to left implied a clockwise orientation). Thanks Ralph Boland

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Beginners March 2019