vector field



On 21.10.2012 12:58, Jaime Villate wrote:
> On 10/21/2012 06:25 AM, Adam wrote:
>> Can I use your image and code ? ( what licence )
>> I would like to put it to commons
>> http://commons.wikimedia.org/wiki/Category:Images_with_Maxima_CAS_source_code
>>
> OK, please do. Jaime
Thx.

I have found that orbits are on exponential spirals :
http://www.suitcaseofdreams.net/powers_complex.htm

Below  is a next try

Adam




/* --------------- code ------------- */
kill(all)$
remvalue(all)$

/* for starting point = e^t use tMin = 1 */

GiveParametric(radius, tMin,tMax) :=
parametric(radius^t*cos(t),radius^t*sin(t),t,tMin,tMax)$




compile(all);


exterior:GiveParametric(1.05, 1, 6*%pi)$
interior:GiveParametric(0.90, 1, 12*%pi)$
boundary:GiveParametric(1.0, 1, 1+2*%pi)$


draw2d(file_name = "iteration8",
         pic_width=1000,
         pic_height= 1000,
      terminal  = 'svg,


              title         = "Hyperbolic Spiral",
              user_preamble = "set grid polar ; set size square; set 
size square;set key out;set key top right ;set xtics 0.5; set mxtics 0.5 ",
              nticks        = 200,
              xrange        = [-2,2],
              yrange        = [-2,2],


              color         = blue,
              line_width    = 3,
              key = "in",
              interior,
              key = "out",
              color = green,
              exterior,

              key = "unit circle",
              color = red,

              boundary

  )$