P controller

*To*: mathgroup at smc.vnet.net*Subject*: [mg127059] P controller*From*: Phoenix <mirko.tavano at live.com>*Date*: Wed, 27 Jun 2012 04:11:31 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

Hi there! I have to plot the following function but I can't and i don't know why! Clear["Global`*"] Fi = .1; do = .18; Ao = Pi*do^2/4; Cd = .61; g = 9.81; A = 5; hss = (Fi/(Ao*Cd))^2*(1/(2*9.81)); F[t_] := { If[t < 10, hSP = hss, hSP = 2*hss]; DSolve[{h'[x] == (hSP - h[x])/A, h[0] == hss}, h, x] } Plot[F[t], {t, 10, 20}] It should be h=hss when t<10; h=E^(-0.2` x) (-2.115297927011188` + 4.230595854022376` E^(0.2` x)) when t>0. I need them in the same graph. Thanks!