MATLAB: I am trying to accomplish this same task using the find() command but I’m not sure how.

findMATLABpiecewise function

clear all
n = 1
for k = 0:.1:6
    x(n) = k
    if (2 <= x(n))&&(x(n) <= 4)
        y(n) = 2*k
    else
        y(n) = -5*k
    end
    n=n+1
end
plot(x,y)

Best Answer

Here is a version that uses a logical vector in place of the find function: 
x = 0:0.1:6;
y = -5*x;
lv = (2 <= x) & (x <= 4);                       % Logical Vector Of ‘x’ Elements Satisfying Conditions
y(lv) = 2*x(lv ~= 0);
figure
plot(x,y)
A version using the find function would be: 
x = 0:0.1:6;
y = -5*x;
idx = find((2 <= x) & (x <= 4));                % Index Vector Of ‘x’ Elements Satisfying Conditions
y(idx) = 2*x(idx);
figure
plot(x,y)
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