Archimedean spiral: Difference between revisions

=={{header|Lambdatalk}}==

<syntaxhighlight lang="Scheme">

1) from polar to cartesian coordinates

x = r*cos(t) = (a+b*t)*cos(t)

y = r*sin(t) = (a+b*t)*sin(t)

2) define the curve

{def CURVE

{lambda {:a :b :t}

{* {+ :a {* :b :t}} {cos :t}}

{* {+ :a {* :b :t}} {sin :t}}

}}

-> CURVE

3) and draw it using SVG

{{SVG 580}

{g {AXES 580 580}

{polyline {@ points="{S.map {CURVE 5 4}

{S.serie 0 {* 10 {PI}} 0.1}}"

{stroke red 3}}

}}}

</syntaxhighlight>

The ouput can be seen in http://lambdaway.free.fr/lambdawalks/?view=archimedian_spiral