How to add equation to function
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Angel Hiram Torres Mota
on 21 Jun 2019
Edited: madhan ravi
on 21 Jun 2019
I need to add my equation (60+(2.13*(t^2))-(0.0013*(t^4))+(0.000034*(t^4.751))) to a function but I cant figure it out. What I've tried just comes out as an error. Please help.
k=1;
for t = 0:2:100;
h(k) = (60+(2.13*(t^2))-(0.0013*(t^4))+(0.000034*(t^4.751)));
k = k+1;
if h>=0
disp(h);
end
end
This is what I tried but it doesnt work.
k=1;
for t = 0:2:100;
h(k) = rocket(t)
k = k+1;
if h>=0
disp(h);
end
end
function h(k) = rocket(t)
h(k) = (60+(2.13*(t^2))-(0.0013*(t^4))+(0.000034*(t^4.751)));
end
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Accepted Answer
madhan ravi
on 21 Jun 2019
Edited: madhan ravi
on 21 Jun 2019
Note: the following can be done trivially without a loop by vectorisation.
t = 0:2:100;
h=zeros(size(t));
for k=1:numel(t);
h(k) = rocket(t(k))
if h(k)>=0
disp(h(k));
end
end
function h = rocket(t)
h = (60+(2.13*(t^2))-(0.0013*(t^4))+(0.000034*(t^4.751)));
end
Without loop:
t = 0:2:100;
h = rocket(t);
fprintf('h >= 0:%f\n',h(h>=0))
function h = rocket(t)
h = (60+(2.13*(t.^2))-(0.0013*(t.^4))+(0.000034*(t.^4.751)));
end
1 Comment
More Answers (2)
Star Strider
on 21 Jun 2019
Except for your ‘rocket’ function, most of that looks as though it should work.
Leave out the subscript reference when you are declaring your function, and within your function, since ‘k’ is not defined within your function, and is not necessary anyway.
Try this instead:
function h = rocket(t)
h = (60+(2.13*(t^2))-(0.0013*(t^4))+(0.000034*(t^4.751)));
end
2 Comments
Adam Danz
on 21 Jun 2019
Edited: Adam Danz
on 21 Jun 2019
rocketFcn = @(x)(60+(2.13*(x^2))-(0.0013*(x^4))+(0.000034*(x^4.751)));
tm = 0:2:100;
h = zeros(size(tm));
for t = 1:numel(tm)
h(t) = rocketFcn(tm(t));
if h(t)>=0
disp(h(t));
end
end
Note that I added ".^" to your rocket function. This allows you to apply vectors to its input so you can avoid the loop.
tm = 0:2:100
h2 = rocketFcn(tm);
% The two lines above produces the same output as the for-loop!
isequal(h,h2)
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