MATLAB: Defining a function in script file

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i want to code following kind of differential eqn in my script file
[t,y]=ode(@(t,y) [[qin-k{y^1.5- (y-b)^1.5}] /Area],t1span,h0)
where, b=f(t)=8.89e-5*t^3 – 4.57e-3*t^2 + 2.27e-1*t – 9.52e-3
area = f(y) = (1.6e-3*y^4 – 2.76e-2*y^3+ 1.4e-1*y^2 – 1.1e-1*y + 0.287)*1e6
when i substitute b and area in my DE, it gets very long and so messy. How can i pre-define b as f(t) and area as f(y) so that i can write my DE eqn in terms of b and area, not in the expanded terms of t and y

Best Answer

b = @(t) 8.89e-5*t^3 - 4.57e-3*t^2 + 2.27e-1*t - 9.52e-3;
area = @(y) (1.6e-3*y^4 - 2.76e-2*y^3+ 1.4e-1*y^2 - 1.1e-1*y + 0.287)*1e6
%taking a guess at the DE since you didn't use valid matlab syntax
[t, y] = ode(@(t, y) qin-k*(y^1.5- (y-b(t))^1.5) / Area(y), t1span, h0);
Not that b and area could also be written:
b = @(t) polyval([8.89e-5, -4.57e-3, 2.27e-1, -9.52e-3], t);
area = @(y) polyval([1.6e-3, -2.76e-2, 1.4e-1, -1.1e-1, 0.287], y) * 1e6;
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