Fermat's spiral
E620680
Fermat's spiral is a plane curve whose radius grows with the square root of the angle, often used to model naturally occurring spiral patterns such as those in sunflowers and other phyllotactic arrangements.
Observed surface forms (1)
| Surface form | Occurrences |
|---|---|
| Fermat spiral | 1 |
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
mathematical object
ⓘ
plane curve ⓘ spiral ⓘ |
| belongsTo | family of spirals with power-law radius-angle relation ⓘ |
| classification | algebraic spiral ⓘ |
| comparedTo |
Archimedean spiral
ⓘ
logarithmic spiral ⓘ |
| coordinateRelation | x = r cos θ, y = r sin θ with r = a√θ ⓘ |
| definedInCoordinateSystem | polar coordinates ⓘ |
| differsFrom |
Archimedean spiral where radius grows linearly with angle
ⓘ
logarithmic spiral where radius grows exponentially with angle ⓘ |
| field |
differential geometry
ⓘ
geometry ⓘ mathematical biology ⓘ |
| hasAlternativeName | parabolic spiral ⓘ |
| hasApplication |
computer graphics phyllotaxis algorithms
ⓘ
procedural generation of plant-like patterns ⓘ visualization of uniform point distributions in a disk ⓘ |
| hasAsymptoticBehavior |
radius tends to 0 as θ tends to 0
ⓘ
radius tends to infinity as θ tends to infinity ⓘ |
| hasBranch |
branch for θ ≤ 0
ⓘ
branch for θ ≥ 0 ⓘ |
| hasCurvatureBehavior | curvature decreases as θ increases ⓘ |
| hasEquation |
r = a·√θ
ⓘ
r^2 = a^2·θ ⓘ |
| hasIndependentVariable | θ (polar angle) ⓘ |
| hasParameter | a (scale parameter) ⓘ |
| hasProperty |
arms are equally spaced in angle for constant increments of θ
ⓘ
can generate nearly uniform density of points when combined with golden angle increments ⓘ often combined with golden angle for realistic phyllotaxis models ⓘ two symmetric branches with respect to the origin ⓘ |
| hasSelfIntersection | no self-intersections for θ ≠ 0 ⓘ |
| hasSymmetry | point symmetry about the origin ⓘ |
| namedAfter | Pierre de Fermat NERFINISHED ⓘ |
| passesThroughPoint | origin ⓘ |
| powerLawExponent | 1/2 ⓘ |
| radiusGrowthLaw | radius grows with the square root of the angle ⓘ |
| relatedToConcept |
Fibonacci numbers
NERFINISHED
ⓘ
golden angle ⓘ phyllotactic spirals ⓘ |
| usedInConstruction |
low-discrepancy point sets on the plane
ⓘ
sunflower seed packing models ⓘ |
| usedToModel |
arrangement of leaves
ⓘ
cactus spine patterns ⓘ phyllotaxis ⓘ pinecone scale patterns ⓘ spiral patterns in plants ⓘ sunflower seed patterns ⓘ |
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Fermat spiral