MAKE A MEME
View Large Image
| View Original: | Transmission line animation open short.gif (300x80) | |||
| Download: | Original | Medium | Small | Thumb |
| Courtesy of: | commons.wikimedia.org | More Like This | ||
| Keywords: Transmission line animation open short.gif en Two transmission lines the top one terminated at an open-circuit the bottom terminated at a short circuit Red color indicates high voltage and blue indicates low voltage Black dots represent electrons See also File Transmission_line_animation_open_short2 gif for an alternate version 2012-08-04 own Sbyrnes321 cc-zero Source code <source lang python> C Steven Byrnes 2014 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 Use Python 3 style division a/b is real division a//b is integer division from __future__ import division import subprocess os directory_now os path dirname os path realpath __file__ import pygame as pg from numpy import pi asarray real exp frames_in_anim 30 animation_loop_seconds 2 time in seconds for animation to loop one cycle bgcolor 255 255 255 white split_line_color 0 0 0 line down the middle is black ecolor 0 0 0 electron color is black pygame draws pixel-art not smoothed Therefore I am drawing it bigger then smoothly shrinking it down img_height 240 img_width 900 final_height 80 final_width 300 ~23 megapixel limit for wikipedia animated gifs assert final_height final_width frames_in_anim < 22e6 transmission line wire length and thickness and y-coordinate of each wire tl_length int img_width 9 tl_thickness 27 tl_open_top_y int img_height 1 tl_open_bot_y tl_open_top_y + 42 tl_short_top_y int img_height 62 tl_short_bot_y tl_short_top_y + 42 wavelength 0 6 tl_length 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 200+55 V 200-55 V 200-55 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 f_phase_at_right r_phase_at_right make a pygame surface representing a colored wire f_phase and r_phase are the phases of the forward and reverse waves respectively def V x z tl_length-x-1 return 0 5 real exp 1j f_phase_at_right + 2 pi z/wavelength + exp 1j r_phase_at_right - 2 pi z/wavelength imgarray rgb_from_V V x for y in range tl_thickness for x in range tl_length return pg surfarray make_surface asarray imgarray def e_path param f_phase_top_right r_phase_top_right which as param goes 0 to 1 this returns a dictionary 'pos' is x y the coordinates of the corresponding point on the electron dot path; 'f_phase' and 'r_phase' are the phases for the forward and reflected waves for an electron at that point on the path top_right means right side of the top wire which is either 'open' or 'short' for which transmission line we're talking about d -18 pixels between electron path and corresponding wires Open transmission line if which 'open' path_length 2 tl_length howfar param path_length go right along top transmission line if howfar < tl_length x howfar y tl_open_top_y - d f_phase f_phase_top_right + 2 pi tl_length-x / wavelength r_phase r_phase_top_right - 2 pi tl_length-x / wavelength return 'pos' x y 'f_phase' f_phase 'r_phase' r_phase go left along bottom transmission line x 2 tl_length - howfar y tl_open_bot_y + tl_thickness + d f_phase f_phase_top_right + 2 pi tl_length-x / wavelength r_phase r_phase_top_right - 2 pi tl_length-x / wavelength return 'pos' x y 'f_phase' f_phase 'r_phase' r_phase Short transmission line path_length 2 tl_length + 3 tl_thickness + 4 d + + tl_short_bot_y - tl_short_top_y howfar param path_length at the beginning go right along top wire if howfar < tl_length x howfar y tl_short_top_y - d f_phase f_phase_top_right + 2 pi tl_length-x / wavelength r_phase r_phase_top_right - 2 pi tl_length-x / wavelength return 'pos' x y 'f_phase' f_phase 'r_phase' r_phase at the end go left along bottom wire if path_length - howfar < tl_length x path_length - howfar y tl_short_bot_y + tl_thickness + d f_phase f_phase_top_right + 2 pi tl_length-x / wavelength r_phase r_phase_top_right - 2 pi tl_length-x / wavelength return 'pos' x y 'f_phase' f_phase 'r_phase' r_phase in the middle f_phase f_phase_top_right r_phase r_phase_top_right top part of short if tl_length < howfar < tl_length + tl_thickness + d x howfar y tl_short_top_y - d bottom part of short elif tl_length < path_length - howfar < tl_length + tl_thickness + d x path_length - howfar y tl_short_bot_y + tl_thickness + d vertical part of short else x tl_length + tl_thickness + d y tl_short_top_y - d + howfar - tl_length + tl_thickness + d return 'pos' x y 'f_phase' f_phase 'r_phase' r_phase 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 f_phase_open_top_right -2 pi frame / frames_in_anim + pi/2 r_phase_open_top_right f_phase_open_top_right f_phase_short_top_right -2 pi frame / frames_in_anim r_phase_short_top_right f_phase_short_top_right + pi initialize surface surf pg Surface img_width img_height surf fill bgcolor ; draw transmission line open_top_wire_surf make_wire_surf f_phase_open_top_right r_phase_open_top_right surf blit open_top_wire_surf 0 tl_open_top_y open_bot_wire_surf make_wire_surf f_phase_open_top_right + pi r_phase_open_top_right + pi surf blit open_bot_wire_surf 0 tl_open_bot_y short_top_wire_surf make_wire_surf f_phase_short_top_right r_phase_short_top_right surf blit short_top_wire_surf 0 tl_short_top_y short_bot_wire_surf make_wire_surf f_phase_short_top_right + pi r_phase_short_top_right + pi surf blit short_bot_wire_surf 0 tl_short_bot_y draw short wire color rgb_from_V 0 pg draw line surf color tl_length + tl_thickness//2 tl_short_top_y tl_length + tl_thickness//2 tl_short_bot_y+tl_thickness-1 tl_thickness draw line down the middle pg draw line surf split_line_color 0 img_height//2 img_width img_height//2 12 draw electrons num_electrons 60 equilibrium_params x/ num_electrons-1 for x in range num_electrons for eq_a in equilibrium_params for which in 'open' 'short' f_phase_top_right f_phase_open_top_right if which 'open' else f_phase_short_top_right r_phase_top_right r_phase_open_top_right if which 'open' else r_phase_short_top_right temp e_path eq_a f_phase_top_right r_phase_top_right which f_phase temp'f_phase' r_phase temp'r_phase' displacement is always pi/2 out of phase with current But compared to voltage it's +pi/2 for forward and -pi/2 for reverse because voltage reflection is negative of current reflection displacement 0 5 real exp 1j f_phase+pi/2 + exp 1j r_phase-pi/2 now_a eq_a + displacement/ 8 num_electrons now_pos e_path now_a f_phase_top_right r_phase_top_right which 'pos' pg draw circle surf ecolor tup_round now_pos 4 0 shrunk_surface pg transform smoothscale surf final_width final_height pg image save shrunk_surface filename_listframe seconds_per_frame animation_loop_seconds / frames_in_anim frame_delay str int seconds_per_frame 100 Use the convert command part of ImageMagick to build the animation command_list 'convert' '-delay' frame_delay '-loop' '0' + filename_list + 'anim gif' 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 | ||||
