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How to label a circle from 0 to 360

Posted: Sun Nov 12, 2017 10:43 pm
by Shonya
Hello,

I wonder if it's possible to label a regular circle from 0 to 360 degree. Basically draw a protractor.


Image

Thank you.

Re: How to label a circle from 0 to 360

Posted: Sun Nov 12, 2017 10:47 pm
by RoryOF
Perhaps an invisible 360 sided polygon behind the circle?

Re: How to label a circle from 0 to 360

Posted: Mon Nov 13, 2017 1:08 pm
by Villeroy
A chart generated in Calc and copied over to a Draw page.

Re: How to label a circle from 0 to 360

Posted: Mon Nov 13, 2017 6:43 pm
by acknak
Yes, it's possible, but not easily (could be more or less easy depending on how many labels you want). You can create the division lines using Edit > Duplicate ... but you'd have to create the labels and place them manually.

I think Villeroy is on the right track: use Calc and/or Chart to do the heavy lifting, then copy into OO Draw. You can use Paste Special to paste the chart as an editable Draw object so it can be tweaked in Draw.

Re: How to label a circle from 0 to 360

Posted: Mon Nov 13, 2017 7:18 pm
by John_Ha
I am a mere mortal and Villeroy's circle was beyond me :crazy:

It can easily be done by Copy and Rotate, Copy and Rotate, Copy and Rotate ...

1. Draw a vertical line. This line is at 90 degrees. I added a small circle to tell me where the centre needs to be.

2. Select the line > Copy. Click in the page to un-select. Right-click the background > Paste. This creates a new copy on top of the original line (Note - you can do it with text.)

3. Modify > Rotate. This adds the rotate handle. Drag the handle to where you want the centre. right-click the line > Position and size > Rotation > type in 100 degrees. This moves the copy line 10 degrees anti-clockwise.

4. Go to step 2 and repeat until all are done. If you want to get clever, select multiple lines, group them, and copy and rotate them :super:
Clipboard01.png
If you add the text for the number, you can group the text and the line into a single unit. Now, when you select the group and rotate and copy, the text will be replicated as well. Un-group to edit the text.
Text grouped and rotated
Text grouped and rotated
Clipboard03.png (2.74 KiB) Viewed 6545 times
A proper CAD drawing system usually has a "Replicate - Multiple copy and shift/rotate" command so you can do 35 copies in one go.
 Edit: So does Draw.

There is a Rotate option in Edit > Duplicate ..., (which I did not know about - thanks acknak) which allows you to create multiple copies. Unfortunately I cannot see a way to set the rotation centre - it uses the centre of the object selected to rotate. If you adjusted the object so it was "twice too long" it would then rotate about the "end of the object you want". 
If this solves the problem, please view your first post in this thread and click the Edit button (top right in the post) and add [Solved] in front of the subject.

Re: How to label a circle from 0 to 360

Posted: Mon Nov 13, 2017 7:35 pm
by Villeroy
John_Ha wrote:I am a mere mortal and Villeroy's circle was beyond me :crazy:
Sorry. ;)
Fill out A1:A360
Start the chart wizard
Type: Pie Chart
Chart elements: no legend
[Finish]
Select the one data series
Call "Insert Labels" from the context menu
Call the labels format dialog
Change the "Placement" from "best fit" (which does not really fit here) to "outside".
Choose a small font.

Re: How to label a circle from 0 to 360

Posted: Mon Nov 13, 2017 7:38 pm
by John_Ha
Ah!!!! Got it!

Re: How to label a circle from 0 to 360

Posted: Mon Nov 13, 2017 11:32 pm
by John_Ha
John_Ha wrote:If you add the text for the number, you can group the text and the line into a single unit. Now, when you select the group and rotate and copy, the text will be replicated as well. Un-group to edit the text.
...
Unfortunately I cannot see a way to set the rotation centre - it uses the centre of the object selected to rotate. If you adjusted the object so it was "twice too long" it would then rotate about the "end of the object you want".
See below where I copy-rotated the original line through 180 degrees to give me "twice as long centred on the centre". I selected both and used Edit > Duplicate ..., and rotated both items by 30 degrees, with 5 copies to give a total of 12 divisions.

Re: How to label a circle from 0 to 360

Posted: Wed Nov 15, 2017 3:23 am
by musikai
Or let the turtle do the job!
But the Turtle has his home in LibreOffice and works in Writer.
:ucrazy:

What?
In LibreOffice Writer you can can enable the LibreLogo Toolbar and write a little program to let "the turtle" draw a Draw graphic.
You then can copy the graphic into Draw if you want.
Playing with the Turtle was much fun and I excuse its little shortage in precision when it comes to exact degrees.
About LibreLogo commands:
https://en.wikipedia.org/wiki/LibreLogo
https://help.libreoffice.org/Writer/LibreLogo_Toolbar
Turtle.png

Re: How to label a circle from 0 to 360

Posted: Wed Nov 15, 2017 1:35 pm
by Villeroy
Thank you very much.

Re: How to label a circle from 0 to 360

Posted: Wed Nov 15, 2017 2:06 pm
by musikai
John_Ha wrote: A proper CAD drawing system usually has a "Replicate - Multiple copy and shift/rotate" command so you can do 35 copies in one go.
 Edit: So does Draw.

There is a Rotate option in Edit > Duplicate ..., (which I did not know about - thanks acknak) which allows you to create multiple copies. Unfortunately I cannot see a way to set the rotation centre - it uses the centre of the object selected to rotate. If you adjusted the object so it was "twice too long" it would then rotate about the "end of the object you want". 
Ah, good to know!!!

Re: How to label a circle from 0 to 360

Posted: Wed Nov 15, 2017 2:13 pm
by RoryOF
If one was going to print out the protractor, two problems may arise: firstly, paper/card is not a dimensionally stable base; it will expand differently on each of its axes as humidity changes. Secondly, a printer may not render a circle as an exact circle - it may be OK for visual purposes, but may be slightly elliptical when accurately measured.

Of course, for normal hand drawing, these problems may not be of significance, but one should be aware of the potential for errors in the most exacting circumstances.