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Thread: Plot a circle/spiral (2000)

20050918, 20:22 #1
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Plot a circle/spiral (2000)
This has been driving nuts for a little while now.
I have a created a column of values that will be the various radii lengths of a spiral at a given angle. I would like to XY scatter plot these values radius/angle to depict the spiral and after fruitless hours of searching cannot see how to plot them. I tried a reasonable attempt in VB a while back but it meant splitting the circle into quadrants and using various cos and sin values. I would prefer a one off function that will allow me to plot directly from the sheet...is this possible?Jerry

20050918, 20:30 #2
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Re: Plot a circle/spiral (2000)
Some more info, perhaps, or the worksheet with the data you have?

20050918, 20:45 #3
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Re: Plot a circle/spiral (2000)
I am trying to plot the Golden Section(see image below).
In column A I have degrees(0 to 720), column Degrees converted to radians, column C, the Sin () of column B[this may be wrong assumption] and Column D calculates the radius of the spiral at a given angle[formula not required as it is just a numerical value]
<table border=1><td>Degrees</td><td>As Radians</td><td>Sin(Radians)</td><td>Radius</td><td>1</td><td>0.017453293</td><td>0.999847695</td><td>0.210768058</tr><td>2</td><td>0.034906585</td><td>0.999390827</td><td>0.210918062</td></tr></table>Jerry

20050918, 21:06 #4
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Re: Plot a circle/spiral (2000)
Hi Hans
I think I may have found something that I can use. I realised I was searching for the wrong thing. I have found this Equiangular Spirals.
It appears to have what I need to work it out, thanks for your time.Jerry

20050918, 21:20 #5
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Re: Plot a circle/spiral (2000)
Ok, that's fine.
If someone else still needs it, here is my attempt (attached).

20050918, 21:35 #6
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Re: Plot a circle/spiral (2000)
What can I say Hans. That is fantastic. I shall compare my values against yours as I have used a different way to calculate my various radii but it is a learning curve <img src=/S/pun.gif border=0 alt=pun width=22 height=18>
Jerry

20050918, 21:51 #7
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Re: Plot a circle/spiral (2000)
Hi Hans
Just as a follow up, I thought I would show you my attempt....same result just using slightly different method to get radii....Thanks once again... I have a big cheesy grin on my faceJerry

20050918, 22:02 #8
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Re: Plot a circle/spiral (2000)
Both methods are basically the same, only I made the spiral go outwards, you made it go inwards.

20050918, 22:08 #9
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Re: Plot a circle/spiral (2000)
Granted....nothing wrong about our methods they were both correct, just we used slightly different methods to calculate out radii. Thanks, speak to you soon.
Jerry