Файл:VFPt Дипольное поле.svg

# вставьте этот код в конец VectorFieldPlot 1.3 doc  =  FieldplotDocument ( 'VFPt_Dipole_field' ,  commons = True ,  width = 700 ,  height = 600 ,  unit = 100 ) R  =  1.55 sca  =  2.4 ;  lw  =  1.0 field  =  Field ({ 'dipoles' :[[ 0 ,  0 ,  0 ,  -1 ]]}) F = lambda t : sc.dot ( field.F ( [ R * cos ( t ), R * sin ( t )]) , [ cos ( t ) , sin ( t ) ] ) Fi = lambda t1 : ig . quad ( F , 0 , t1 )[ 0 ] * R Fsum = Fi ( pi ) line = FieldLine ( field , [ 0 , 5 ], directions = 'forward' , maxr = 10 ) doc . draw_line ( line , linewidth = lw , arrows_style = { 'dist' : 6 - 2 * R , 'scale' : sca , 'max_arrows' : 2 , 'min_arrows' : 2 , 'fixed_ends' :[ False , True , True , False ]}) n = 15 p = - 0,3 для i в диапазоне ( n ): a = ( i + 0,5 +                                              p )  /  ( n  +  2 * p )  t  =  op . brentq ( lambda  t : Fi ( t )  -  a * Fsum ,  0 ,  pi )  если  abs ( i  -  n / 2 )  >  4 :  line  =  FieldLine ( field ,  [ R * cos ( t ),  R * sin ( t )],  directions = ' both ' )  doc . draw_line ( line ,  linewidth = lw ,  arrows_style = { 'dist' : 2 * R ,  'scale' : sca ,  'max_arrows' : 2 ,  'min_arrows' : 1 ,  'fixed_ends' :[ True ,  False ,  False ,  True ]})  elif  ( i  !=  7 ):  line  =  FieldLine ( field ,  [ R * cos ( t ),  R * sin ( t )],  directions = 'both' ,  maxr = 3 )  doc . draw_line ( line ,  linewidth = lw ,  arrows_style = { 'dist' : 2 * R ,  'scale' : sca ,  'max_arrows' : 1 ,  'min_arrows' : 1 ,  'fixed_ends' :[ False ,  False ,  False ,  True ]})  line  =  FieldLine ( field ,  [ R * cos( t ),  - R * sin ( t )],  направления = 'both' ,  maxr = 3 )  doc . draw_line ( line ,  linewidth = lw ,  arrows_style = { 'dist' : 2 * R ,  'scale' : sca ,  'max_arrows' : 1 ,  'min_arrows' : 1 ,  'fixed_ends' : [ True ,  False ,  False ,  False ]}) n2  =  3 для  j  в  [ - 1 , 1 ]:  для  i  в  диапазоне ( n2 ):  a  =  ( i  +  0,5  -  p )  /  ( n  +  2 * p )  t  =  op . brentq ( lambda  t1 :  ig . quad ( lambda  r : field . F ([ r ,  0. ])[ 1 ],  R ,  t1 )[ 0 ]  -  a * Fsum ,  0.1 ,  R )  линия  =  FieldLine ( field ,  [ j * t ,  0. ],  directions = 'both' )  doc . draw_line ( line ,  linewidth = lw ,  arrows_style = { 'dist' : 2 * R ,  'scale' : sca ,  'max_arrows' : 1 ,  'min_arrows' : 1 }) Re  =  0.855 earth  =  doc . draw_object ('g' ,  { 'id' : 'земля' }) doc.draw_object ( ' circle' , { 'r' : Re , 'cx' : '0' , ' cy' : ' 0' , 'style' : 'fill:#ffffff; stroke:#000000; stroke-width:0.01' }, group = earth ) doc.draw_object ( 'path' , { 'd' : 'M - {0} ,0 A {0} , {1} 0 0 1 {0} , 0'.format ( Re , 0.2 * Re ), 'style' : 'fill : none; stroke:#000000 ; stroke-width:0.01' }, group = earth ) text_N = doc . draw_object ( 'text' , { 'text-anchor' : 'middle' , 'x' : '0' , 'y' : 37 , 'transform' : 'translate(0,0.7) scale(0.002,-0.002)' , 'style' : 'fill:#000000; stroke:none ; font-size:100px; font-family:Bitstream Vera Sans' }) text_N.text = ' N' text_S = doc . draw_object ( 'text' , { 'text-anchor' : 'middle' , 'x' : '0' , 'y' : 37 , 'transform' : 'translate(0,-0.7) scale(0.002,-0.002)' , 'style' : 'fill: # 000000; stroke:none ; font -size:100px; font -family:Bitstream Vera Sans' }) text_S.text = 'S' doc.write ()