Brand Spanking New GDL Book

[Aaron Bourgoin]

Cadimage Tools scripting wizards have written a big book on GDL - to be published shortly.

http://blog.cadimagetools.com/

[Anonymous]

It's that pest again.
At least in my US version of 12 the default value for zzyzx when taking the default "new object" is; 3'-3 3/8"
So when you run the 2dfull View button on lower part of page 29 you won't get .86 of course, at least not in US version.
But of course I was determined to see what the problem was, which I did NOT see at first, I just figured I had made another screw up.
I know this is NOT the point you are making, but what the heck.
So the closest to .86 I could get in 1/8" increments was to set zzyzx to
2'-11 3/8" which got me .858525 after subtracting the seatThick of .04
Kinda proud of myself, if I do say so myself;-)
(Boy, have I got a long way to go)
Now onward, to slay "Naming Variables"

[Erika Epstein]

Yes, I came accross the same thing. There are several places where imperial differs from the metric.

[Anonymous]

Yes, but I believe it would have complicated too many things to have both systems in one book, would it not?
I was just commenting on that, so that others would not think they had misunderstood something based on calculated numbers being somewhat different if your in the US as I did.
I'm really happy with what I've been learning, especially having started out with virtually zero knowledge of gdl, with that, and the limited time I can spend of this new adventure of course it's going to be small steps for me.

[Erika Epstein]

My steps aren't that much longer than yours.

Ideally we would be using the Metric system here. As we aren't, I think it important to note where there are differences and why. The book needs to address this subject so that as we learn GDL. If you are going to market this book to a country that uses Imperial, than it should be addressed. Those of us that need to work in Imperial learn where and how to make the conversions. Andrew does do this in places, but not consistently. Or he could have an addendum page(s) that can be referenced when appropriate. I don't think it is much work and I do think it is necessary.
There was an example of early on, can't find it this minute where the example returned a value of ±3'-3" instead of '1'. Yes, usually you can figure out, that 1 is a meter = 3'-3". But , given the number of posts here in the forum that deal with this lack-of conversion from metric to imperial, again i think it is necessary. And, not everyone who buys the book participates in this forum

Archicad calculates in metric. In countries that use imperial, if we want to have parameters in Imperial, each time there must be a line of code to do the conversion.

Notoriously the calculate section of archicad is inconsistent in making conversions (don't get Karl started) so results are wrong not just wacky. Search the forum to find discussions.

Another example is inconsistency in font sizes. While usually they are in pts or inches, there a number of places where they are in mm and so noted and a many others also in mm but not noted. We become accustomed to realizing that a font size of 3 probably means it is mm not pts or inches. Again, not everyone knows or wants to be bothered.

My 2 cents. And this in no way takes away from what a tremendous job Andrew has done. I'm learning things I've been struggling with for years and/or not dared to attempt before.

[Anonymous]

... I think it important to note where there are differences and why. ... Those of us that need to work in Imperial learn where and how to make the conversions.

There are two things I can do for readers.
1/ I can provide an addendum that outlines how to convert from metric to imperial units and vice versa. This document can also explain differences between input/output formats. Perhaps the document could also outline how to change your project settings to metric units for the purposes of following the text?
2/ I can go through the book page by page and provide alternative values/output results.

Let me know which of these would be most useful, I can do both if necessary. Any other suggestions will be much appreciated.

Thanks very much for your comments.

[Anonymous]

Hi Andrew
Think I got most of the general ideas until…
On page 34, first sentence example.
array 2d [3] [2] = 3
as you say represents row3 ,column 2 (kinda like a spread sheet?)
What I don’t get is where the “= 3” came from.
Is that a hypothetical number in that position, or am I suppose to be able to calculate or get that it "=3" from the above array statement?
Or more likely I missed something earlier on?

[Anonymous]

Hi Lec

Yes, the '3' is just an arbitrary value that I assigned to that element of the array. As you say, its like typing the value '3' into the 3rd row and 2nd column of a spreadsheet.

[Anonymous]

Throughout the GDL Handbook there are examples which include values given in metres or millimetres. To change these values to feet and inches, use the following conversion factors:

• 1mm = 0.03937"
  1m = 39.37"

To convert to inches, multiply the mm or m value by the appropriate factor. Thus 3.2m = 126", while 50mm = 2". Note that in both examples I've rounded to the nearest inch. You can round to the nearest inch, or to the nearest half-inch, quarter-inch etc. for smaller dimensions.

To change from inches to millimetres or metres, use the conversion factors:

• 1" = 25.04mm
  1" = 0.0254m

[Thomas Holm]

Andrew wrote:
To change from inches to millimetres or metres, use the conversion factors:

• 1" = 25.04mm
  1" = 0.0254m

Hey, those are different!
1" = 25.4 mm and nothing else!

[Anonymous]

Good point, not sure how the extra zero slipped in! Thanks Thomas for correcting me so promptly.