Using a variable as an index inside a Which

Question

I'm trying to make a list of functions by parts and then graph them. But I have troubles accessing a variable element in list G, how could I solve it?

G = {x^2, Sin[x], (x - \[Pi])^2}
Y = {}
xl = {{-2, 0}, {0, \[Pi]}, {\[Pi], \[Pi] + 2}}

For[i = 1, i <= 3, i++, 
 AppendTo[Y, Which[xl[[i, 1]] < x < xl[[i, 2]], G[[i]]]]
]

Plot[Y, {x, -3, 6}]

Answer 1

I think you want to plot this:

Plot[Piecewise[{{x^2, x < 0}, {Sin[x], x < \[Pi]}}, (x - \[Pi])^2], {x, -3, 6}]

which gives you:

I figured it out with Which:

G = {x^2, Sin[x], (x - \[Pi])^2}
xl = {{-2, 0}, {0, \[Pi]}, {\[Pi], \[Pi] + 2}}
Y = Flatten[Table[{xl[[i, 1]] < x < xl[[i, 2]], G[[i]]}, {i, 3}]]
Plot[Which @@ Y, {x, -3, 6}]

which gives a slightly different output: