# File:Parabolic trajectory.svg

Original file(SVG file, nominally 641 × 265 pixels, file size: 8 KB)

# Structured data

### Captions

Add a one-line explanation of what this file represents
 Description Illustration of a parabolic trajectory. Date 20 December 2007, 05:58 (UTC) Source self-made with MATLAB. Tweaked in Inkscape. Author Oleg Alexandrov
 I, the copyright holder of this work, release this work into the public domain. This applies worldwide.In some countries this may not be legally possible; if so:I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.

## Source code (MATLAB)

```% illustration of a parabolic trajectory

function main()

L=0.8;
s=0.1;
q=-0.4;
N=100;

arrow_size = 0.1;
sharpness = 20;
arrow_type = 1;
arrlen = 0.3; % arrow length
tiny = 0.01;

X=linspace(-L, L, N);
Y =L^2 - X.^2;
Xl = linspace(-L-s, L+s, N);

% KSmrq's colors
red    = [0.867 0.06 0.14];
blue   = [0, 129, 205]/256;
green  = [0, 200,  70]/256;
yellow = [254, 194,   0]/256;
white = 0.99*[1, 1, 1];
black = [0, 0, 0];
gray = 0.5*white;
lw = 2.3;

figure(1); clf; hold on; axis equal; axis off;
plot(X, Y, 'linewidth', lw, 'linestyle', '--', 'color', blue);
arrow([q-tiny, L^2-q^2], [q+arrlen-tiny, L^2-q^2-2*q*arrlen], lw, arrow_size, sharpness, arrow_type, red);
ball(q, L^2 - q^2, ball_radius, gray)
plot(Xl, 0*Xl, 'linewidth', 2*lw, 'color', black);

%saveas(gcf, 'Parabolic_trajectory.eps', 'psc2')
plot2svg('Parabolic_trajectory.svg');

function ball(x, y, radius, color) % draw a ball of given uniform color
Theta=0:0.1:2*pi;
H=fill(X, Y, color);
set(H, 'EdgeColor', [0, 0, 0]);

function arrow(start, stop, thickness, arrow_size, sharpness, arrow_type, color)

% Function arguments:
% start, stop:  start and end coordinates of arrow, vectors of size 2
% thickness:    thickness of arrow stick
% arrow_size:   the size of the two sides of the angle in this picture ->
% sharpness:    angle between the arrow stick and arrow side, in degrees
% arrow_type:   1 for filled arrow, otherwise the arrow will be just two segments
% color:        arrow color, a vector of length three with values in [0, 1]

% convert to complex numbers
i=sqrt(-1);
start=start(1)+i*start(2); stop=stop(1)+i*stop(2);
rotate_angle=exp(i*pi*sharpness/180);

% points making up the arrow tip (besides the "stop" point)
point1 = stop - (arrow_size*rotate_angle)*(stop-start)/abs(stop-start);
point2 = stop - (arrow_size/rotate_angle)*(stop-start)/abs(stop-start);

if arrow_type==1 % filled arrow

% plot the stick, but not till the end, looks bad
t=0.5*arrow_size*cos(pi*sharpness/180)/abs(stop-start); stop1=t*start+(1-t)*stop;
plot(real([start, stop1]), imag([start, stop1]), 'LineWidth', thickness, 'Color', color);

% fill the arrow
H=fill(real([stop, point1, point2]), imag([stop, point1, point2]), color);
set(H, 'EdgeColor', 'none')

else % two-segment arrow
plot(real([start, stop]), imag([start, stop]),   'LineWidth', thickness, 'Color', color);
plot(real([stop, point1]), imag([stop, point1]), 'LineWidth', thickness, 'Color', color);
plot(real([stop, point2]), imag([stop, point2]), 'LineWidth', thickness, 'Color', color);
end
```

## File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current05:58, 20 December 2007641 × 265 (8 KB)Oleg Alexandrov (talk | contribs){{Information |Description=Illustration of a parabolic trajectory. |Source=self-made with MATLAB |Date=~~~~~ |Author= Oleg Alexandrov |Permission=See below |other_versions= }} {{PD-self}} ==Source code (MATLAB)==
• You cannot overwrite this file.

There are no pages that use this file.

## File usage on other wikis

The following other wikis use this file:

• Usage on ast.wikipedia.org
• Usage on cs.wikipedia.org
• Usage on de.wikipedia.org
• Usage on de.wikibooks.org
• Usage on en.wikipedia.org
• Usage on en.wikiversity.org
• Usage on es.wikipedia.org
• Usage on gl.wikipedia.org
• Usage on hi.wikipedia.org
• Usage on id.wikipedia.org
• Usage on pl.wikipedia.org
• Usage on pt.wikipedia.org
• Usage on simple.wikipedia.org
• Usage on tr.wikipedia.org