How to plot two equations on two different plots

I need to plot Altitude vs Time and Velocity vs Time. But there are two possible equations for each graph, depending on the value of "t". How do I get both of the correct equations to show up on two different graphs?

prompt = 'Time of flight? (s) ';

t = input(prompt)

if (t <= 45)

h = 15*t.^2;

fprintf('Altitude: %dm\n\n', h)

v = 30*t;

fprintf('Velocity: %dm/s\n\n', v);

plot(t, h), xlabel('Time (s)'), ylabel('Altitude (m)'), title('Altitude vs Time')

plot(t, v), xlabel('Time (s)'), ylabel('Velocity (m/s)'), title('Velocity vs Time')

elseif (t > 45)

h = 30375 + (1350*t) + 0.5*(-11.5)*t.^2;

fprintf('Altitude: %dm\n\n', h )

v = 1350 - 11.5*t;

fprintf('Velocity: %dm/s\n\n', v);

plot(t, h), xlabel('Time (s)'), ylabel('Altitude (m)'), title('Altitude vs Time')

plot(t, v), xlabel('Time (s)'), ylabel('Velocity (m/s)'), title('Velocity vs Time')

end

Answer 1

[Arif Hoq]

try this code.

as your output is only a single integer so it's better specify Line style. here i used 'o'. for different plots use subplot.

prompt = 'Time of flight? (s) ';
t = input(prompt)
if (t <= 45)
    h = 15*t.^2;
    fprintf('Altitude: %dm\n\n', h) 
    v = 30*t;
    fprintf('Velocity: %dm/s\n\n', v);
    
    figure(1)
    subplot(2,1,1)
    plot(t, h,'o'), xlabel('Time (s)'), ylabel('Altitude (m)'), title('Altitude vs Time')
    subplot(2,1,2)
    plot(t, v,'o'), xlabel('Time (s)'), ylabel('Velocity (m/s)'), title('Velocity vs Time')
elseif (t > 45)
    h = 30375 + (1350*t) + 0.5*(-11.5)*t.^2;
    fprintf('Altitude: %dm\n\n', h ) 
    
    v = 1350 - 11.5*t;
    fprintf('Velocity: %dm/s\n\n', v);
    
    figure(2)
    subplot(2,1,1)
    plot(t, h,'o'), xlabel('Time (s)'), ylabel('Altitude (m)'), title('Altitude vs Time')
    subplot(2,1,2)
    plot(t, v,'o'), xlabel('Time (s)'), ylabel('Velocity (m/s)'), title('Velocity vs Time')
end

[RetiredCheetoXI]

Thanks! Do you know of any easy way to make it also display the equation used in addition to the point?

[Arif Hoq]

Follow this code:

prompt = 'Time of flight? (s) ';
t = input(prompt)
if t <= 45
    h = 15*t.^2;
    fprintf('Altitude: %dm\n\n', h) 
    v = 30*t;
    fprintf('Velocity: %dm/s\n\n', v);
    
    figure(1)
    subplot(2,1,1)
    plot(t, h,'o'), xlabel('Time (s)'), ylabel('Altitude (m)'), title('Altitude vs Time')
    equation = sprintf('h = 15*t^2');
    text(t, h, equation, 'FontSize', 12, 'Color', 'r','HorizontalAlignment','center','VerticalAlignment','top');
    subplot(2,1,2)
    plot(t, v,'o'), xlabel('Time (s)'), ylabel('Velocity (m/s)'), title('Velocity vs Time')
    equation = sprintf('v = 30*t');
    text(t, v, equation, 'FontSize', 12, 'Color', 'r', 'HorizontalAlignment','center','VerticalAlignment','top');
elseif t > 45
    h = 30375 + (1350*t) + 0.5*(-11.5)*t.^2;
    fprintf('Altitude: %dm\n\n', h ) 
    
    v = 1350 - 11.5*t;
    fprintf('Velocity: %dm/s\n\n', v);
    
    figure(2)
    subplot(2,1,1)
    plot(t, h,'o'), xlabel('Time (s)'), ylabel('Altitude (m)'), title('Altitude vs Time')
    equation = sprintf('h = 30375 + (1350*t) + 0.5*(-11.5)*t^2');
    text(t, h, equation, 'FontSize', 12, 'Color', 'r', 'HorizontalAlignment','center','VerticalAlignment','top');
    subplot(2,1,2)
    plot(t, v,'o'), xlabel('Time (s)'), ylabel('Velocity (m/s)'), title('Velocity vs Time')
    equation = sprintf('v = 1350 - 11.5*t');
    text(t, v, equation, 'FontSize', 12, 'Color', 'r', 'HorizontalAlignment','center','VerticalAlignment','top');
end