%This code plots and animates data from my N-body code.  I commented out
%the plots of Mercury, Venus, Uranus, and Neptune.
clear
clc

%This writes to an avi file that I converted to MP4 using EasyHtml5Video.
writerObj = VideoWriter('planet_alt.avi');
open(writerObj);

%Here I am loading the text file that I created in my N-body code and
%assigning each column of values in the file to a vector.
    load planet.txt;    %Sun
    x1=planet(:,1);
    y1=planet(:,2);
    z1=planet(:,3);
    
    x2=planet(:,4);     %Mercury
    y2=planet(:,5);
    z2=planet(:,6);
    
    x3=planet(:,7);     %Venus
    y3=planet(:,8);
    z3=planet(:,9);
    
    x4=planet(:,10);    %Earth
    y4=planet(:,11);
    z4=planet(:,12);
    
    x5=planet(:,13);    %Mars
    y5=planet(:,14);
    z5=planet(:,15);
    
    x6=planet(:,16);    %Jupiter
    y6=planet(:,17);
    z6=planet(:,18);
    
    x7=planet(:,19);    %Saturn
    y7=planet(:,20);
    z7=planet(:,21);
    
    x8=planet(:,22);    %Uranus
    y8=planet(:,23);
    z8=planet(:,24);
    
    x9=planet(:,25);    %Neptune
    y9=planet(:,26);
    z9=planet(:,27);
    
    dt = 50;%don't need to specify variable type in MatLab
    total_time = size(x4,1); %This is the time it takes to form the total length of the vector x4.  All vectors are the same length.
    
    %This loop plots points along the position vectors x y z of the
    %planets.  It pauses along the way so that the entire vectors are not
    %instantly plotted.  This creates the animation.
    
    whitebg('k')
    axis vis3d 
    
    for i = 1:dt:total_time           
        
        %These are coordinates for each mass that is displayed in the
        %animation.  I converted floats to strings.
        sun_x_coordinate = num2str(x1(i));
        sun_y_coordinate = num2str(y1(i));
        sun_z_coordinate = num2str(z1(i));
        
        earth_x_coordinate = num2str(x4(i));        
        earth_y_coordinate = num2str(y4(i));
        earth_z_coordinate = num2str(z4(i));
        
        mars_x_coordinate = num2str(x5(i));
        mars_y_coordinate = num2str(y5(i));
        mars_z_coordinate = num2str(z5(i));
        
        jupiter_x_coordinate = num2str(x6(i));
        jupiter_y_coordinate = num2str(y6(i));
        jupiter_z_coordinate = num2str(z6(i));
        
        %Here are the plots for one frame of the video
        plot3(x1(1:dt:i),y1(1:dt:i),z1(1:dt:i),'.r','MarkerSize',20); %plots Sun
        hold on
%         plot3(x2(1:dt:i),y2(1:dt:i),z2(1:dt:i),'-b','MarkerSize',5);   %plots Mercury
%         hold on
%         plot3(x3(1:dt:i),y3(1:dt:i),z3(1:dt:i),'-g','MarkerSize',5);  %plots Venus
%         hold on
        plot3(x4(1:dt:i),y4(1:dt:i),z4(1:dt:i),'.b','MarkerSize',5);  %plots Earth
        hold on
        plot3(x5(1:dt:i),y5(1:dt:i),z5(1:dt:i),'.g','MarkerSize',5);  %plots Mars
        hold on
        plot3(x6(1:dt:i),y6(1:dt:i),z6(1:dt:i),'.c','MarkerSize',5);   %plots Jupiter 
%         plot3(x7(1:dt:i),y7(1:dt:i),z7(1:dt:i),'-g','MarkerSize',5);  %plots Saturn
%         hold on
%         plot3(x8(1:dt:i),y8(1:dt:i),z8(1:dt:i),'-c','MarkerSize',5);  %plots Uranus
%         hold on
%         plot3(x9(1:dt:i),y9(1:dt:i),z9(1:dt:i),'-y','MarkerSize',5);   %plots Neptune 
        
         axis fill
         
         %this keeps the axis fixed.  Particles are only visible when they are within axis limits.
         axis([-5.0, 5.0, -5.0, 5.0, -5.0, 5.0]) 
        
        %These are handles for the coordinates that are displayed
        h = text(1.0,1.2,4.5,['\color{red}Sun\color{white}  ', sun_x_coordinate, '   ', sun_y_coordinate, '   ', sun_z_coordinate]);
        h2 = text(1.0,1.2,3.5,['\color{blue}Earth\color{white}  ', earth_x_coordinate, '   ', earth_y_coordinate, '   ', earth_z_coordinate]);
        h3 = text(1.0,1.2,2.5,['\color{green}Mars\color{white}  ', mars_x_coordinate, '   ', mars_y_coordinate, '   ', mars_z_coordinate]);
        h4 = text(1.0,1.2,1.5,['\color{lightBlue}Jupiter\color{white}  ', jupiter_x_coordinate, '   ', jupiter_y_coordinate, '   ', jupiter_z_coordinate]);
        
        %This captures a frame of the plot for the ith point in each
        %vector.
        movie_func(i) = getframe;
        %pause(.30)     %this is another way of creating animations
        
        %This loop repeats each frame 10 times so the movie appears to play slowly.
        for j = 1:10        
            writeVideo(writerObj,movie_func(i));
        end
        
        %handles are deleted to prevent text being displayed over more
        %text.
        delete(h)       
        delete(h2)
        delete(h3)
        delete(h4)
        
    end
     
   close(writerObj);