Speed optimization of Mean calculation in a previous calculated data range

Question

I have following problem: My calculations work quite well with the shown testdata, the only problem is the speed of it. My original dataset is about 64000 datapoints, and it takes several minutes to calculate the following script. I have the clue that my 2 For loops could be the reason, has anyone an idea how I could speed it up??

I have following datasets

Signal={{1., 0.5}, {1.1, 0.721739}, {1.2, 0.860952}, {1.3, 0.932368}, {1.4, 
  0.966584}, {1.5, 0.982954}, {1.6, 0.990987}, {1.7, 0.995064}, {1.8, 
  0.997207}, {1.9, 0.998372}, {2., 0.999024}, {2.1, 0.999401}, {2.2, 
  0.999624}, {2.3, 0.999759}, {2.4, 0.999842}, {2.5, 0.999895}, {2.6, 
  0.999929}, {2.7, 0.999951}, {2.8, 0.999966}, {2.9, 0.999976}, {3., 
  0.999983}, {3.1, 0.999988}, {3.2, 0.999991}, {3.3, 0.999993}, {3.4, 
  0.999995}, {3.5, 0.999996}, {3.6, 0.999997}, {3.7, 0.999998}, {3.8, 
  0.999998}, {3.9, 0.999999}, {4., 0.999999}, {4.1, 0.999999}, {4.2, 
  0.999999}, {4.3, 1.}, {4.4, 1.}, {4.5, 1.}, {4.6, 1.}, {4.7, 
  1.}, {4.8, 1.}, {4.9, 1.}, {5., 1.}, {5.1, 1.}, {5.2, 1.}, {5.3, 
  1.}, {5.4, 1.}, {5.5, 1.}, {5.6, 1.}, {5.7, 1.}, {5.8, 1.}, {5.9, 
  1.}, {6., 1.}, {6.1, 1.}, {6.2, 1.}, {6.3, 1.}, {6.4, 1.}, {6.5, 
  1.}, {6.6, 1.}, {6.7, 1.}, {6.8, 1.}, {6.9, 1.}, {7., 1.}, {7.1, 
  1.}, {7.2, 1.}, {7.3, 1.}, {7.4, 1.}, {7.5, 1.}, {7.6, 1.}, {7.7, 
  1.}, {7.8, 1.}, {7.9, 1.}, {8., 1.}, {8.1, 1.}, {8.2, 1.}, {8.3, 
  1.}, {8.4, 1.}, {8.5, 1.}, {8.6, 1.}, {8.7, 1.}, {8.8, 1.}, {8.9, 
  1.}, {9., 1.}, {9.1, 1.}, {9.2, 1.}, {9.3, 1.}, {9.4, 1.}, {9.5, 
  1.}, {9.6, 1.}, {9.7, 1.}, {9.8, 1.}, {9.9, 1.}, {10., 1.}, {10.1, 
  1.}, {10.2, 1.}, {10.3, 1.}, {10.4, 1.}, {10.5, 1.}, {10.6, 
  1.}, {10.7, 1.}, {10.8, 1.}, {10.9, 1.}, {11., 1.}, {11.1, 
  1.}, {11.2, 1.}, {11.3, 1.}, {11.4, 1.}, {11.5, 1.}, {11.6, 
  1.}, {11.7, 1.}, {11.8, 1.}, {11.9, 1.}, {12., 1.}, {12.1, 
  1.}, {12.2, 1.}, {12.3, 1.}, {12.4, 1.}, {12.5, 1.}, {12.6, 
  1.}, {12.7, 1.}, {12.8, 1.}, {12.9, 1.}, {13., 1.}, {13.1, 
  1.}, {13.2, 1.}, {13.3, 1.}, {13.4, 1.}, {13.5, 1.}, {13.6, 
  1.}, {13.7, 1.}, {13.8, 1.}, {13.9, 1.}, {14., 1.}, {14.1, 
  1.}, {14.2, 1.}, {14.3, 1.}, {14.4, 1.}, {14.5, 1.}, {14.6, 
  1.}, {14.7, 1.}, {14.8, 1.}, {14.9, 1.}, {15., 1.}, {15.1, 
  1.}, {15.2, 1.}, {15.3, 1.}, {15.4, 1.}, {15.5, 1.}, {15.6, 
  1.}, {15.7, 1.}, {15.8, 1.}, {15.9, 1.}, {16., 1.}, {16.1, 
  1.}, {16.2, 1.}, {16.3, 1.}, {16.4, 1.}, {16.5, 1.}, {16.6, 
  1.}, {16.7, 1.}, {16.8, 1.}, {16.9, 1.}, {17., 1.}, {17.1, 
  1.}, {17.2, 1.}, {17.3, 1.}, {17.4, 1.}, {17.5, 1.}, {17.6, 
  1.}, {17.7, 1.}, {17.8, 1.}, {17.9, 1.}, {18., 1.}, {18.1, 
  1.}, {18.2, 1.}, {18.3, 1.}, {18.4, 1.}, {18.5, 1.}, {18.6, 
  1.}, {18.7, 1.}, {18.8, 1.}, {18.9, 1.}, {19., 1.}, {19.1, 
  1.}, {19.2, 1.}, {19.3, 1.}, {19.4, 1.}, {19.5, 1.}, {19.6, 
  1.}, {19.7, 1.}, {19.8, 1.}, {19.9, 1.}, {20., 1.}}

MicrowavePulse={{1, 1}, {2, 1}, {3, 1}, {4, 1}, {5, 1}, {6, 0}, {7, 0}, {8, 0}, {9,0}, {10, 0}, {11, 1}, {12, 1}, {13, 1}, {14, 1}, {15, 1}, {16, 0},{17, 0}, {18, 0}, {19, 0}, {20, 0}}

My goal is to get the Meanof Signal data, in the range whenever the MicrowavePulse is on and off. That means I want to get 4x (in this case) the Meanof all Signal data points lying from x=1 to x=5, from x=6 to x=10, from x=11 to x=15 and from x=16 till x=20.

I have written a For loop in order to receive sublists, for each time the MW is on or off, that means I get 4 sublists.

NumberMWData = Length[MicrowavePulse]
MicrowavePulse = MicrowavePulse[[All, 2]];
MWListOnOFF := {}; 
MWOneList := {};
For[i = 1, i <= NumberMWData, i++, 
MWOneList = Append[MWOneList, i]; 
If[i == NumberMWData || (MicrowavePulse[[i]] > 0 && 
 MicrowavePulse[[i + 1]] <= 0) || (MicrowavePulse[[i]] <= 0 && 
 MicrowavePulse[[i + 1]] > 0),
MWListOnOFF = Append[MWListOnOFF, MWOneList];
MWOneList = {}
]
]

(* {{1, 2, 3, 4, 5}, {6, 7, 8, 9, 10}, {11, 12, 13, 14, 15}, {16, 17, 18,19, 20}} *)

These lists are applied to cut the Signal data in the same x range like the MW pulse in lists, so that I can calculate the Mean in each of the Signal lists and the result are four mean values for the Signal data.

ResultMean := {}; 
For[i = 1, i <= Length[MWListOnOFF], i++,
start = MWListOnOFF[[i]][[1]];
stop = MWListOnOFF[[i]][[Length[MWListOnOFF[[i]]]]];
ResultMean = Append[ResultMean,Mean[Select[Signal, start <= #[[1]] <= stop &]]];
]

(*{{3., 0.974232}, {8., 1.}, {13., 1.}, {18., 1.}}*)

Answer 1

indices = SplitBy[MicrowavePulse, Last][[All, All, 1]]
(* {{1, 2, 3, 4, 5}, {6, 7, 8, 9, 10}, {11, 12, 13, 14, 15}, {16, 17, 18, 19, 20}} *)

Mean[Signal[[#]]] & /@ indices
(* {{1.2,0.796329},{1.7,0.992917},{2.2,0.99953},{2.7,0.999943}} *)

or

Extract[Signal, List /@ indices, Mean]
(* {{1.2,0.796329},{1.7,0.992917},{2.2,0.99953},{2.7,0.999943}} *)