In R-studio I want to know how I would save a loop result without deleting the previous loop result

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In this code I want to calculate the trimmed mean and variance of trimmed mean for normal distribution in many value of alpha ( I want to calculate the value of the each alpha from 1 to 13 ) and storage the result in the data.frame then print the all result But the problem is that the new result storages over the previous result and at the end i end up getting only the last result of alpha value.

ProDistFun<- data.frame(matrix(nrow=91, ncol=4))
colnames(ProDistFun)<-c("x","Alpha","Trimmed Mean","Variance Of Trimmed Mean")
mu=7    # Mean Value
sigma2=4   # Variance value
for (alpha in c(0.001,0.01,0.025,0.05,0.1,0.25,0.375))
{
for(i in 1:13)
{
ProDistFun[i,1]<-i
ProDistFun[i,2]<-alpha
# The trimmed mean
a=qnorm(alpha, mean=mu, sd=sqrt(sigma2))
b=qnorm(1-alpha, mean=mu, sd=sqrt(sigma2))
fun_TM <- function(x) ((x*exp(-0.5*((x-mu)/sqrt(sigma2))^2))/((1-2*alpha)*(sqrt(2*pi*sigma2))))
MT1 <- integrate(fun_TM, a, b)
MT <-MT1$value
ProDistFun[i,3]<-MT
# The variance of trimmed mean
fun_VTM <- function(x) ((((x-MT)^2)*exp(-0.5*((x-mu)/sqrt(sigma2))^2))/(sqrt(2*pi*sigma2)))
fVTM <- integrate(fun_VTM, a, b)
fV <- fVTM$value
VT=((fV+(alpha*(a-MT)^2)+(alpha*(b-MT)^2))/((1-2*alpha)^2))
ProDistFun[i,4]<-VT
}
}
print(ProDistFun)
2

There are 2 answers

2
Chuck P On BEST ANSWER

Edited Sept 30 12:23 hours

It's still not totally clear to me what you're trying to accomplish with x since you use it in confusing ways, but using most of your code and simplifying drastically but still using a for loop

Create an empty dataframe without the matrix contortions.

ProDistFun <- data.frame(
   x = integer(0), 
   Alpha = numeric(0), 
   Trimmed_Mean = numeric(0), 
   Variance_Of_Trimmed_Mean = numeric(0)
   )

Assign your two constants. IMPORTANT NOTE -- throughout your code please stop treating assignment <- as the same thing as = it will cause problems down the road.

mu <- 7    # Mean Value
sigma2 <- 4   # Variance value

Pull your two functions out of the loops (no point in rerunning them every iteration). I have no idea if they are correct but they seem to work. It also seems to me that in these functions you want the x value to be the value of i so I've made that change. If you don't you get 13 iterations of identical

fun_TM <- function(x) {
   ((i*exp(-0.5*((i-mu)/sqrt(sigma2))^2))/((1-2*alpha)*(sqrt(2*pi*sigma2))))
}

fun_VTM <- function(x) {
   ((((i-MT)^2)*exp(-0.5*((i-mu)/sqrt(sigma2))^2))/(sqrt(2*pi*sigma2)))
}

Now we run the nested loops of alpha and i. We build a row to add to our empty dataframe ProDist_df and then last step is rbind the newrow to it. Note as stated in the help file for integrate we need to Vectorize.

for (alpha in c(0.001,0.01,0.025,0.05,0.1,0.25,0.375)) {
   for (i in 1:13) {
      a <- qnorm(alpha, mean = mu, sd = sqrt(sigma2))
      b <- qnorm(1 - alpha, mean = mu, sd = sqrt(sigma2))
      MT1 <- integrate(Vectorize(fun_TM), a, b)
      MT <- MT1$value
      fVTM <- integrate(Vectorize(fun_VTM), a, b)
      fV <- fVTM$value
      VT <- ((fV+(alpha*(a-MT)^2)+(alpha*(b-MT)^2))/((1-2*alpha)^2))
      newrow <- data.frame(x = i, 
                           Alpha = alpha, 
                           Trimmed_Mean = MT, 
                           Variance_Of_Trimmed_Mean = VT)
      ProDist_df <- rbind(ProDist_df, newrow)
   }
}

ProDist_df
#>     x Alpha Trimmed_Mean Variance_Of_Trimmed_Mean
#> 1   1 0.001   0.02744577                0.2003378
#> 2   2 0.001   0.21710028                0.5148306
#> 3   3 0.001   1.00307392                1.4849135
#> 4   4 0.001   3.20833233                0.6092747
#> 5   5 0.001   7.49244239                9.4048587
#> 6   6 0.001  13.08172721              109.7134117
#> 7   7 0.001  17.29412878              262.6203021
#> 8   8 0.001  17.44230295              195.0733274
#> 9   9 0.001  13.48639629               30.3828344
#> 10 10 0.001   8.02083083                3.2269398
#> 11 11 0.001   3.67793771               18.0605860
#> 12 12 0.001   1.30260169               12.5886402
#> 13 13 0.001   0.35679506                4.5613376
#> 14  1 0.010   0.02104086                1.4856627
#> 15  2 0.010   0.16643643                1.7087503
#> 16  3 0.010   0.76899043                2.5612272
#> 17  4 0.010   2.45961619                2.3689151
#> 18  5 0.010   5.74396001                1.1324626
#> 19  6 0.010  10.02889499               28.3270524
#> 20  7 0.010  13.25826466               76.9619814
#> 21  8 0.010  13.37185999               50.5144290
#> 22  9 0.010  10.33912801                2.7851234
#> 23 10 0.010   6.14904048                9.7709433
#> 24 11 0.010   2.81963158               18.3179999
#> 25 12 0.010   0.99861856               11.4783190
#> 26 13 0.010   0.27353117                4.8704116
#> 27  1 0.025   0.01828687                3.5703608
#> 28  2 0.025   0.14465195                3.7170106
#> 29  3 0.025   0.66833905                4.3472611
#> 30  4 0.025   2.13768272                4.1121498
#> 31  5 0.025   4.99214637                1.0747081
#> 32  6 0.025   8.71623613               12.2965566
#> 33  7 0.025  11.52292107               37.4315915
#> 34  8 0.025  11.62164818               22.0916831
#> 35  9 0.025   8.98586347                1.0699878
#> 36 10 0.025   5.34420680               13.1972079
#> 37 11 0.025   2.45057652               19.1385400
#> 38 12 0.025   0.86791169               12.3691446
#> 39 13 0.025   0.23772931                6.5199633
#> 40  1 0.050   0.01619943                7.3749079
#> 41  2 0.050   0.12813995                7.4154400
#> 42  3 0.050   0.59204825                7.6768541
#> 43  4 0.050   1.89366655                6.8889173
#> 44  5 0.050   4.42229360                2.4843697
#> 45  6 0.050   7.72127906                5.6367092
#> 46  7 0.050  10.20758133               19.2763445
#> 47  8 0.050  10.29503875               10.2078727
#> 48  9 0.050   7.96012848                2.5125393
#> 49 10 0.050   4.73416638               16.5558668
#> 50 11 0.050   2.17084357               21.3087060
#> 51 12 0.050   0.76883970               15.1092609
#> 52 13 0.050   0.21059254                9.9710784
#> 53  1 0.100   0.01419911               17.3206584
#> 54  2 0.100   0.11231710               17.1281634
#> 55  3 0.100   0.51894156               16.5102647
#> 56  4 0.100   1.65983477               13.8052303
#> 57  5 0.100   3.87622451                6.3261279
#> 58  6 0.100   6.76784806                2.9011142
#> 59  7 0.100   8.94713932                9.2952208
#> 60  8 0.100   9.02379741                4.8107658
#> 61  9 0.100   6.97720412                6.0182204
#> 62 10 0.100   4.14958694               22.3456468
#> 63 11 0.100   1.90278571               28.0669010
#> 64 12 0.100   0.67390263               23.5641219
#> 65 13 0.100   0.18458837               19.4835253
#> 66  1 0.250   0.01195695              101.3283283
#> 67  2 0.250   0.09458127               99.3524957
#> 68  3 0.250   0.43699624               91.6992768
#> 69  4 0.250   1.39773265               71.1428700
#> 70  5 0.250   3.26413547               35.4870897
#> 71  6 0.250   5.69914690                7.1958771
#> 72  7 0.250   7.53430941                4.8250199
#> 73  8 0.250   7.59886254                4.6624497
#> 74  9 0.250   5.87544385               18.9156520
#> 75 10 0.250   3.49433163               57.7975362
#> 76 11 0.250   1.60231955               87.6386891
#> 77 12 0.250   0.56748763               98.7559156
#> 78 13 0.250   0.15544029              101.2808652
#> 79  1 0.375   0.01129729              591.0212507
#> 80  2 0.375   0.08936330              578.6087319
#> 81  3 0.375   0.41288753              529.2387893
#> 82  4 0.375   1.32062094              401.4184815
#> 83  5 0.375   3.08405591              197.9457725
#> 84  6 0.375   5.38472985               37.5416149
#> 85  7 0.375   7.11864801                5.0996822
#> 86  8 0.375   7.17963979                7.6766516
#> 87  9 0.375   5.55130064               59.4024907
#> 88 10 0.375   3.30155234              228.2708772
#> 89 11 0.375   1.51392096              415.5768786
#> 90 12 0.375   0.53617983              529.7332481
#> 91 13 0.375   0.14686478              575.9244272
0
SteveM On

The general way to save all atomic values generated in a loop is to create an empty vector before the loop and then append the new values to the vector inside the loop. E.g.,

output <- vector()
for (i in 1:5) {
      newvalue <- i
      output <- c(output, newvalue)
}