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Euler-spiral - Messages
#1 Posted: 11/14/2023 3:13:22 AM
Why I can not to plot the Euler spiral curvature?
1-10-Euler-spiral.sm (175 KiB) downloaded 71 time(s).

1-10-Euler-spiral.sm (175 KiB) downloaded 71 time(s).
#2 Posted: 11/14/2023 4:46:11 AM
SMath native integration is a purely numerical procedure. Derivatives are symbolic ones. You would need to replace the symbolic derivatives by approximations.
Maxima can handle the derivatives. Funny enough, Maxima can't display the integral values x(t), y(t), neither can it plot them.
But you just asked for the curvature

Euler-spiral_Maxima.sm (28 KiB) downloaded 66 time(s).
Maxima can handle the derivatives. Funny enough, Maxima can't display the integral values x(t), y(t), neither can it plot them.
But you just asked for the curvature

Euler-spiral_Maxima.sm (28 KiB) downloaded 66 time(s).
Martin Kraska
Pre-configured portable distribution of SMath Studio: https://en.smath.info/wiki/SMath%20with%20Plugins.ashx
2 users liked this post
#3 Posted: 11/14/2023 4:53:38 AM
Thanks, Martin.
No solution in pure SMath?
No solution in pure SMath?
#4 Posted: 11/14/2023 5:58:30 AM
Here is a solution in pure (AKA Maxima-free) SMath.
The derivatives are replaced by difference quotients with a fixed perturbation h. Sooner or later this h is too big for a precise approximation, therefore, the value of the curvature deteriorates for large values of t.
Perhaps the fixed interval integrator also is to be blamed for the loss of precision.
Another M to patent?

Euler-spiral_Kr.sm (15 KiB) downloaded 67 time(s).
The derivatives are replaced by difference quotients with a fixed perturbation h. Sooner or later this h is too big for a precise approximation, therefore, the value of the curvature deteriorates for large values of t.
Perhaps the fixed interval integrator also is to be blamed for the loss of precision.
Another M to patent?
Euler-spiral_Kr.sm (15 KiB) downloaded 67 time(s).
Martin Kraska
Pre-configured portable distribution of SMath Studio: https://en.smath.info/wiki/SMath%20with%20Plugins.ashx
#5 Posted: 11/14/2023 6:11:13 AM
Hi. These are another two options.
1-10-Euler-spiral - option 1.sm (174 KiB) downloaded 76 time(s).
1-10-Euler-spiral - option 2.sm (176 KiB) downloaded 70 time(s).
Best regards.
Alvaro.
1-10-Euler-spiral - option 1.sm (174 KiB) downloaded 76 time(s).
1-10-Euler-spiral - option 2.sm (176 KiB) downloaded 70 time(s).
Best regards.
Alvaro.
2 users liked this post
#7 Posted: 11/14/2023 1:52:31 PM
#8 Posted: 11/14/2023 4:44:15 PM
https://community.ptc.com/t5/Mathcad/Euler-spiral/m-p/912205/thread-id/209391
#10 Posted: 11/14/2023 7:39:05 PM
WroteWhy I can not to plot the Euler spiral curvature ?
Cornu = Euler = Fresnel = Clothoid ... all same.
Maths Spirals Euler-Cornu.sm (17 KiB) downloaded 71 time(s).
Maths Spirals_ANY.sm (26 KiB) downloaded 70 time(s).
#11 Posted: 11/14/2023 8:27:47 PM
WroteCornu = Euler = Fresnel = Clothoid ... all same.
In the document ANY spiral ... set
c:= 0.30634896253
k:= -0.848622607416
r:= 0.25 ... immaterial, just to plot on same canvas.
You will have the Golden spiral considered Fibonacci.
Cheers ... Jean.
#12 Posted: 11/15/2023 9:00:51 AM
#13 Posted: 11/15/2023 10:28:26 AM
Hi. Using the numerical limit procedure from this post
1-10-Euler-spiral - option 2.sm (40 KiB) downloaded 73 time(s).

Best regards.
Alvaro.
1-10-Euler-spiral - option 2.sm (40 KiB) downloaded 73 time(s).
Best regards.
Alvaro.
1 users liked this post
Valery Ochkov 11/15/2023 12:44:00 PM
#14 Posted: 11/15/2023 8:57:32 PM
#16 Posted: 11/15/2023 11:12:37 PM
#17 Posted: 11/15/2023 11:55:45 PM
Nice picture. This is a conic helicoid.

HelliCone.sm (148 KiB) downloaded 67 time(s).
Best regards.
Alvaro.
HelliCone.sm (148 KiB) downloaded 67 time(s).
Best regards.
Alvaro.
2 users liked this post
#18 Posted: 11/16/2023 8:16:36 AM
The plots are interactive (drag to rotate, Ctrl-Mousewheel to zoom). Yet, they are not really performant, takes approx. 3 seconds to update.

knots.sm (272 KiB) downloaded 65 time(s).
knots.sm (272 KiB) downloaded 65 time(s).
Martin Kraska
Pre-configured portable distribution of SMath Studio: https://en.smath.info/wiki/SMath%20with%20Plugins.ashx
1 users liked this post
Valery Ochkov 11/16/2023 8:51:00 AM
#19 Posted: 11/16/2023 8:46:37 AM
#20 Posted: 11/16/2023 9:08:36 AM
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