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| Keywords: Transmission line animation.gif en A lossless transmission line terminated at an impedance-matched load resistor box on right Red color indicates high voltage and blue indicates low voltage Black dots represent electrons See also File Transmission_line_animation3 gif for a newer and simpler version 2012-07-30 own Sbyrnes321 cc-zero Source code <source lang python > C Steven Byrnes 2013 This code is released under the MIT license http //opensource org/licenses/MIT This code runs in Python 2 7 or 3 3 It requires imagemagick to be installed; that's how it assembles images into animated GIFs from __future__ import division import pygame as pg from numpy import cos pi sin asarray import subprocess os directory_now os path dirname os path realpath __file__ frames_in_anim 30 animation_loop_seconds 2 time in seconds for animation to loop one cycle bgcolor 255 255 255 white linecolor 0 0 0 outline of resistor is black ecolor 0 0 0 electron color is black img_height 100 img_width 300 transmission line wire length and thickness and y-coordinate of each wire tl_length img_width 6//7 tl_thickness 5 tl_top_y img_height 4//9 tl_bot_y img_height 5//9 - tl_thickness//2 second term is to keep it symmetric wavelength 0 6 tl_length resistor_length img_height//2 resistor_width resistor_length//3 resistor_center img_width - resistor_width 3//2 img_height//2 top_lead_path tl_length tl_top_y + tl_thickness-1 tl_length img_height//9 resistor_center0 img_height//9 resistor_center bot_lead_path x img_height-y+1 for x y in top_lead_path lead_thickness 2 def rgb_from_V V voltage V varies -1 to +1 Return a color as a function of V Color is a 3-tuple red green blue each 0 to 255 return 100+100 V 100 - 100 V 100-100 V def tup_round tup round each element of a tuple to nearest integer return tuple int round x for x in tup def make_wire_surf phase_at_left make a pygame surface representing a colored wire startphase is phase at left side of the wire imgarray rgb_from_V cos phase_at_left + 2 pi x/wavelength for y in range tl_thickness for x in range tl_length return pg surfarray make_surface asarray imgarray def make_resistor_surf phase_at_top make a pygame surface representing the resistor topphase is phase at top imgarray rgb_from_V cos phase_at_top 1 - 2 y/resistor_length for y in range resistor_length for x in range resistor_width surf pg surfarray make_surface asarray imgarray pg draw rect surf linecolor surf get_rect 1 1-pixel black outline return surf def e_path param phase_top_left as param goes 0 to 1 this returns 'pos' x y 'phase' phi where x y is the coordinates of the corresponding point on the electron dot path and phi is the phase for an electron at that point on the path phase_top_left is phase of the left side of the top wire d 3 pixels between electron path and corresponding wires path_length 2 tl_length - d transmission lines + 2 img_height//3 left vertical leads + 2 resistor_center0 - tl_length + 2 d + lead_thickness + 2 resistor_length//2 - img_height//9 right vertical leads + resistor_length through resistor howfar param path_length move right across top transmission line if howfar < tl_length - d x howfar y tl_top_y - d phase phase_top_left + 2 pi x / wavelength return 'pos' x y 'phase' phase howfar - tl_length - d move up lead if howfar < img_height//3 x tl_length - d y tl_top_y - d - howfar phase phase_top_left + 2 pi tl_length / wavelength return 'pos' x y 'phase' phase howfar - img_height//3 move right to above resistor if howfar < resistor_center0- tl_length + 2 d + lead_thickness x tl_length - d + howfar y img_height//9 - d phase phase_top_left + 2 pi tl_length / wavelength return 'pos' x y 'phase' phase howfar - resistor_center0 - tl_length + 2 d + lead_thickness move down to top of resistor if howfar < resistor_length//2 - img_height//9 x resistor_center0 + d + lead_thickness y img_height//9 - d + howfar phase phase_top_left + 2 pi tl_length / wavelength return 'pos' x y 'phase' phase howfar - resistor_length//2 - img_height//9 move down resistor if howfar < resistor_length x resistor_center0 + resistor_width//2 + d y resistor_center1 - resistor_length//2 + howfar phase phase_top_left + 2 pi tl_length / wavelength return 'pos' x y 'phase' phase howfar - resistor_length beyond here use the mirror symmetry flipdata e_path 1-param phase_top_left flipdata'pos' flipdata'pos'0 img_height - flipdata'pos'1 + 2 return flipdata def main Make and save a drawing for each frame filename_list os path join directory_now 'temp' + str n + ' png' for n in range frames_in_anim for frame in range frames_in_anim phase_top_left -2 pi frame / frames_in_anim phase_top_right phase_top_left + 2 pi tl_length / wavelength initialize surface surf pg Surface img_width img_height surf fill bgcolor ; draw transmission line top_wire_surf make_wire_surf phase_top_left bottom_wire_surf make_wire_surf phase_top_left + pi surf blit top_wire_surf 0 tl_top_y surf blit bottom_wire_surf 0 tl_bot_y draw lead wires color rgb_from_V cos phase_top_right pg draw lines surf color False top_lead_path lead_thickness color rgb_from_V cos phase_top_right + pi pg draw lines surf color False bot_lead_path lead_thickness draw resistor resistor_surf make_resistor_surf phase_top_right surf blit resistor_surf resistor_center0 - resistor_width//2 resistor_center1 - resistor_length//2 draw electrons num_electrons 100 equilibrium_params x/ num_electrons-1 for x in range num_electrons phases e_path a phase_top_left 'phase' for a in equilibrium_params now_params equilibrium_paramsi + sin phasesi / 1 3 num_electrons for i in range num_electrons coords e_path a phase_top_left 'pos' for a in now_params for coord in coords pg draw circle surf ecolor tup_round coord 2 0 pg image save surf filename_listframe seconds_per_frame animation_loop_seconds / frames_in_anim frame_delay str int seconds_per_frame 100 command_list 'convert' '-delay' frame_delay '-loop' '0' + filename_list + 'anim gif' Use the convert command part of ImageMagick to build the animation subprocess call command_list cwd directory_now Earlier we saved an image file for each frame of the animation Now that the animation is assembled we can optionally delete those files if True for filename in filename_list os remove filename main </source> Uploaded with UploadWizard Transmission lines Animations of electronics Impedance Animations of vibrations and waves Images with Python source code | ||||
