How to Input a value, get a result, input that result to calculate another value

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RetiredCheetoXI
RetiredCheetoXI on 7 Feb 2022
The input is time, which then calculates altitude. This value for altitude is then used to get a value for temperature. How do I make this work? The bolded text is what I just added to it and is not working, everything else works on its own.
prompt = 'Time of flight? (s) ';
t = input(prompt);
tx = t-200:t+200;
if (t <= 45)
h = @(x) 15*x.^2;
fprintf('Altitude: %dm\n\n', h(t))
v = @(x) 30*x;
fprintf('Velocity: %dm/s\n\n', v(t));
if (h <= 11000)
T = (h - 44332.30769230768) / -153.84615384615378;
elseif (h <= 25000)
T = 216.66;
elseif (h <= 47000)
T = (h + 47220) / 333.3;
elseif (h <= 53000)
T = 282.66;
elseif (h <= 79000)
T = (h - 115813) / -222.2;
elseif (h <= 90000)
T = 165.66;
elseif (h <= 110000)
T = (h - 48585) / 250;
end
figure(1)
subplot(2,1,1)
plot(t,h(t),'o',tx,h(tx)), xlabel('Time (s)'), ylabel('Altitude (m)'), title('Altitude vs Time')
subplot(2,1,2)
plot(t,v(t),'o',tx,v(tx)), xlabel('Time (s)'), ylabel('Velocity (m/s)'), title('Velocity vs Time')
elseif (t < 117.5)
h = @(x) 30375 + (1350*x) + 0.5*(-11.5)*x.^2;
fprintf('Altitude: %dm\n\n', h(t))
v = @(x) 1350 - 11.5*x;
fprintf('Velocity: %dm/s\n\n', v(t));
if (h <= 11000)
T = (h - 44332.30769230768) / -153.84615384615378;
elseif (h <= 25000)
T = 216.66;
elseif (h <= 47000)
T = (h + 47220) / 333.3;
elseif (h <= 53000)
T = 282.66;
elseif (h <= 79000)
T = (h - 115813) / -222.2;
elseif (h <= 90000)
T = 165.66;
elseif (h <= 110000)
T = (h - 48585) / 250;
end
figure(2)
subplot(2,1,1)
plot(t,h(t),'o',tx,h(tx)), xlabel('Time (s)'), ylabel('Altitude (m)'), title('Altitude vs Time')
subplot(2,1,2)
plot(t,v(t),'o',tx,v(tx)), xlabel('Time (s)'), ylabel('Velocity (m/s)'), title('Velocity vs Time')
end
  3 Comments
Voss
Voss on 8 Feb 2022
Replace h with h(t) everywhere in the bolded text.
h is a function. To get h at some given time t, you have to evaluate the function at that time t. That's what h(t) does.

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Answers (1)

Prahlad Gowtham Katte
Prahlad Gowtham Katte on 18 Feb 2022
Hello,
As mentioned in the comments please change h to h(t) wherever you are using assignment and comparison operators.
The errors which you got are due to "h" as it is a function handle and it cannot be used in comparison and arithmetic operations but h(t) is a return value of type double which can be used.
For more information on function handles please refer to the following link
Hope it helps.

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