matlab经典的小程序

1.分段函数

for x=-pi*6:pi/10:6*pi

y=sin(x);

if y<0

y=0;

end

fprintf('x=%f,y=%f\n',x,y);

end

2．计算距离

x1=input('enter the x1:' );

y1=input('enter the y1:' );

x2=input('enter the x2:' );

y2=input('enter the y2:' );

d=sqrt((x1-x2).^2+(y1-y2).^2);

fprintf('the distance of the two points is :%f',d); v0=input('Enter the 初速度v0:');

h0=input('Enter the 离地高度h0:');

t=0:0.01:5

3．重力加速度

h=-0.5*9.81*t.^2+v0*t+h0;

v=-9.81*t+v0;

plot(t,h,'k-',t,v,'b--');

title(' Plot of h(t) and v(t)');

xlabel('t');

ylabel('h(t)andv(t)');

legend('h(t)','v(t)');

4.坐标转换

function [x, y] = polar2rect(r, theta)

x = r * cos(theta * pi/180);

y = r * sin(theta * pi/180);

5.坐标转换，带参数检验

function [mag, angle] = polar_value(x, y)

msg = nargchk(1,2,nargin);

error(msg);

% If the y argument is missing, set it to 0.

if nargin < 2

y = 0;

end

% Check for (0,0) input argument, and print out

% a warning message.

if x == 0 & y == 0

msg = 'Both x and y are zero: angle is meaningless!'; warning(msg);

end

% Now calculate the magnitude

mag = sqrt(x .^2 + y .^2);

% If the second output argument is present,calculate

% angle in degrees

if nargout == 2

angle = atan2(y,x) * 180/pi;

end

6.三维螺旋线

t = 0:pi/50:10*pi;

plot3(sin(t),cos(t),t)

grid on

axis square

7.subplot

figure(1);

subplot(2,1,1);

x=-pi:pi/20:pi;

y=sin(x);

plot(x,y);

title('Subplot 1 title');

subplot(2,1,2);

x=-pi:pi/20:pi;

y=cos(x);

plot(x,y);

title('Subplot 2 title');

8．Figure

figure(1);

x=x:0.05:2;

y1=exp(x);

plot(x,y1);

figure(2);

y2=exp(-x);

plot(x,y2);

9.保持

x=-pi:pi/20:pi;

y1=sin(x);

y2=cos(x);

plot(x,y1,'b-');

hold on;

plot(x,y2,'k--');

hold off;

legend ('sin x','cos x');

10.极坐标绘图

g = 0.5;

theta = 0:pi/20:2*pi;

gain = 2*g*(1+cos(theta));

% Plot gain

polar (theta,gain,'r-');

title ('Gain versus angle \it\theta');

11.色彩控制

x=0:pi/15:4*pi;

y=exp(2*sin(x));

plot(x,y,'-ko','LineWidth',3.0,'Markersize',6 ,...

'MarkerEdgeColor','r','MarkerFaceColor','g');