Get the mean for every iteration-CodePudding

I'm new in R. Hoping someone could help me.

I am trying to get the mean using for the first values of i for nth iteration, example (first value on first iteration then first two values on 2nd iterations)

How do I go about doing this?

Here is the sample data:

set.seed(1234)

i <- sample(200,100)

CodePudding user response：

An alternative, may be, simpler solution

set.seed(1234)
i <- sample(200,100)
cumsum(i)/(1:100)
#>   [1]  28.00000  54.00000  86.00000  89.75000  94.00000 101.16667 105.71429
#>   [8] 113.25000 116.66667 118.20000 116.36364 115.25000 113.30769 110.21429
#>  [15] 108.13333 108.62500 103.05882 104.33333 102.10526  97.20000 101.66667
#>  [22] 103.81818 101.04348 100.70833 101.56000 105.11538 103.66667 105.96429
#>  [29] 106.55172 104.60000 104.70968 105.53125 104.96970 103.08824 103.42857
#>  [36] 102.55556 104.10811 102.47368 100.94872  98.47500  98.92683 101.00000
#>  [43]  99.79070  99.84091  98.75556  99.52174 100.76596 101.87500 100.95918
#>  [50] 101.66000 100.17647 101.03846 102.37736 100.62963 100.54545  99.14286
#>  [57]  98.01754  99.20690 100.38983 100.15000 101.00000  99.53226  99.68254
#>  [64] 100.34375 100.07692 101.39394 100.17910  99.75000  99.18841  99.85714
#>  [71] 100.35211 100.72222 102.04110 101.02703 100.69333 101.53947 102.44156
#>  [78] 101.89744 101.43038 100.61250 100.83951 102.04878 101.04819  99.95238
#>  [85]  99.12941  98.70930  97.77011  98.44318  98.92135  98.46667  97.45055
#>  [92]  97.31522  97.75269  97.05319  96.84211  97.02083  97.81443  97.93878
#>  [99]  98.92929  99.55000

^{Created on 2022-03-04 by the reprex package (v2.0.1)}

CodePudding user response：

Here's a one-liner to get the result:

sapply(1:100, function(x) mean(i[seq(x)]))
#>   [1]  28.00000  54.00000  86.00000  89.75000  94.00000 101.16667 105.71429
#>   [8] 113.25000 116.66667 118.20000 116.36364 115.25000 113.30769 110.21429
#>  [15] 108.13333 108.62500 103.05882 104.33333 102.10526  97.20000 101.66667
#>  [22] 103.81818 101.04348 100.70833 101.56000 105.11538 103.66667 105.96429
#>  [29] 106.55172 104.60000 104.70968 105.53125 104.96970 103.08824 103.42857
#>  [36] 102.55556 104.10811 102.47368 100.94872  98.47500  98.92683 101.00000
#>  [43]  99.79070  99.84091  98.75556  99.52174 100.76596 101.87500 100.95918
#>  [50] 101.66000 100.17647 101.03846 102.37736 100.62963 100.54545  99.14286
#>  [57]  98.01754  99.20690 100.38983 100.15000 101.00000  99.53226  99.68254
#>  [64] 100.34375 100.07692 101.39394 100.17910  99.75000  99.18841  99.85714
#>  [71] 100.35211 100.72222 102.04110 101.02703 100.69333 101.53947 102.44156
#>  [78] 101.89744 101.43038 100.61250 100.83951 102.04878 101.04819  99.95238
#>  [85]  99.12941  98.70930  97.77011  98.44318  98.92135  98.46667  97.45055
#>  [92]  97.31522  97.75269  97.05319  96.84211  97.02083  97.81443  97.93878
#>  [99]  98.92929  99.55000

^{Created on 2022-03-04 by the reprex package (v2.0.1)}