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Notation for geometry: Line, Segment, Ray, Arc, …

Posted: Mon Aug 25, 2008 11:47 pm
by chuckhale
I need to write line AB, line segment AB, ray AB, arc AB, etc but do not see how to do that in Open Office.

I do have Math Type, but it is a macro that will work with Word, but will not work with Writer.

I also have not been able to resize the equations once I get it into Writer or Impress. Especially for Impress, I need to make it larger for the presentation in order for it to be seen by the entire class.

Re: Line segments

Posted: Tue Aug 26, 2008 2:02 am
by acknak
overline AB

widevec AB

There is no "arc" or "overarc"; it has been requested: Issue 49970: draw arch above characters
You can register there and add your vote (up to two) or comment.

An embedded formula is a freely-resizeable object, but OOo works very hard to prevent you from resizing it, even when it makes sense to do so.

To change the size, select the formula object (green handles), Format > Position and Size > Position and Size > Protect > Size = NO (unchecked). You can now drag any of the green handles to resize the object, but the only way that makes any sense is to hold down the Shift key and drag one of the corners--this scales the size but keeps the aspect constant.

Note that OOo will replace the size protection, so if you need to change the size again later, you have to unprotect it again.

Using this manual scaling method, it's difficult to make your formulas a consistent size, so instead you may want to (in the formula editor), do Format > Font Size > Base Size = 36pt (or whatever), then click "Default". That will become the default base size for any formula created subsequently, but it doesn't apply to existing formulas.

BTW, Have you read the Forum Survival Guide? Please try to stick to one question per topic.

Re: Line segments

Posted: Tue Aug 26, 2008 10:19 am
by RGB
You can also use the "size" command inside the Math object:
size *2 {Your Math}
will double the size for the expression. Be careful that the "size" command works on a "per line" basis: if you use "newline" you need to issue the size command on each line.

Re: Line segments

Posted: Tue Aug 26, 2008 4:02 pm
by chuckhale
I have been able to do overline (line segment) and widevec (ray), but am needing to write "Line AB." Widevec only has the arrow on one end, so it is a ray and not a line.

Thanks for the tip on resizing. However, they don't seem to work. When I select the object (green handles) and choose format, there is nothing under "position and size." It is unlit so it is unavailable. I have been able to change the font size. I am working on changing the color - to make it easier to use in a Powerpoint.

Re: Line segments

Posted: Wed Aug 27, 2008 1:23 am
by Dave
chuckhale wrote:I need to write line AB, line segment AB, ray AB, arc AB, etc but do not see how to do that in Open Office.

I do have Math Type, but it is a macro that will work with Word, but will not work with Writer.
I'm not too clear on what you mean. Do you want the symbolic statements [in which case line segment AB would be written just like that], or do you want to draw and label them, in which case you will need a CAD program, or a geometry construction program.

MathType WILL work in Writer. You will have to copy/paste, first choosing the translator as an equation object. However, I don't know that it contains geometry symbols.

David.

Re: Line segments

Posted: Wed Aug 27, 2008 7:19 am
by acknak
... but am needing to write "Line AB." Widevec only has the arrow on one end, so it is a ray and not a line.

OOo Math can't help you then. It has no support for double-headed arrows in variable widths.

As far as I can see, it has not been requested. You may want to check for yourself and file a request if you don't find one already active.

You can sort of fake it with something like this: AB csup {size *1.4 "↔"} but the spacing and size is not right at all.

You can also create the symbol as a graphic, but that's really tedious and it can't be mixed with an actual formula.

When I select the object (green handles) and choose format, there is nothing under "position and size."

Are you working in Impress, or in Writer?

Anyway, it doesn't matter, it's probably not a good way to go.

If you really need a scalable formula, the most robust way to do it is to create the formula, then copy it to the clipboard, then Edit > Paste Special as "GDI Metafile". The pasted formula will not be a formula but a graphic, which is always scalable. You can also change it's color using the color channel adjustments.

Re: Line segments

Posted: Sat Aug 30, 2008 1:42 am
by Dave
From MathType:
overbar.jpg
overbar.jpg (4.56 KiB) Viewed 14077 times
David.

Re: Line segments

Posted: Mon Sep 15, 2008 11:17 pm
by chuckhale
Dave wrote:From MathType:
overbar.jpg
David.
the command:
"overbar{AB}" does not create that. So it IS possible? How?

Re: Line segments

Posted: Tue Sep 16, 2008 2:41 am
by Dave
I said it was from MathType.
Mathtype.jpg
David.

Re: Line segments

Posted: Tue Sep 16, 2008 5:09 am
by Dave
OK, if you can't do it form OpenOffice Math, then why be reluctant to use MathType?

David.