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我尝试实现一个玩具脚本，用于将小数（以下示例中的输入为 0.21）转换为二进制数字 - 一切正常，除了我不知道如何防止的数字错误：

bin_dec <- function() {

    b <- as.numeric(readline("Input Binary digit: "))

    dec=9999999
    P=9999999
    N=b

    print("N             B          P             U")

    while (dec != b & P != 0) {
       P = N*2
       U = floor(P)
       dec = P%%1
       print(sprintf("%s          2          %s            %s", N, P, U))       
       N = dec
       }
    }

> bin_dec()
Input Binary digit: 0.21
[1] "N             B          P             U"
[1] "0.21          2          0.42          0"
[1] "0.42          2          0.84          0"
[1] "0.84          2          1.68          1"
[1] "0.68          2          1.36          1"
[1] "0.36          2          0.72          0"
[1] "0.72          2          1.44          1"
[1] "0.440000000000000          2          0.879999999999999          0"
[1] "0.879999999999999          2          1.76000000000000          1"
[1] "0.759999999999998          2          1.52000000000000          1"
[1] "0.519999999999996          2          1.03999999999999          1"
[1] "0.039999999999992          2          0.079999999999984          0"
[1] "0.079999999999984          2          0.159999999999968          0"
[1] "0.159999999999968          2          0.319999999999936          0"
[1] "0.319999999999936          2          0.639999999999873          0"
[1] "0.639999999999873          2          1.27999999999975          1"
[1] "0.279999999999745          2          0.559999999999491          0"
[1] "0.559999999999491          2          1.11999999999898          1"
[1] "0.119999999998981          2          0.239999999997963          0"
[1] "0.239999999997963          2          0.479999999995925          0"
[1] "0.479999999995925          2          0.95999999999185          0"
[1] "0.95999999999185          2          1.9199999999837          1"
[1] "0.919999999983702          2          1.83999999996740          1"
[1] "0.839999999967404          2          1.67999999993481          1"
[1] "0.679999999934807          2          1.35999999986961          1"
[1] "0.359999999869615          2          0.71999999973923          0"
[1] "0.71999999973923          2          1.43999999947846          1"
[1] "0.439999999478459          2          0.879999998956919          0"
[1] "0.879999998956919          2          1.75999999791384          1"
[1] "0.759999997913837          2          1.51999999582767          1"
[1] "0.519999995827675          2          1.03999999165535          1"
[1] "0.0399999916553497          2          0.0799999833106995          0"
[1] "0.0799999833106995          2          0.159999966621399          0"
[1] "0.159999966621399          2          0.319999933242798          0"
[1] "0.319999933242798          2          0.639999866485596          0"
[1] "0.639999866485596          2          1.27999973297119          1"
[1] "0.279999732971191          2          0.559999465942383          0"
[1] "0.559999465942383          2          1.11999893188477          1"
[1] "0.119998931884766          2          0.239997863769531          0"
[1] "0.239997863769531          2          0.479995727539062          0"
[1] "0.479995727539062          2          0.959991455078125          0"
[1] "0.959991455078125          2          1.91998291015625          1"
[1] "0.91998291015625          2          1.8399658203125          1"
[1] "0.8399658203125          2          1.679931640625          1"
[1] "0.679931640625          2          1.35986328125          1"
[1] "0.35986328125          2          0.7197265625          0"
[1] "0.7197265625          2          1.439453125          1"
[1] "0.439453125          2          0.87890625          0"
[1] "0.87890625          2          1.7578125          1"
[1] "0.7578125          2          1.515625          1"
[1] "0.515625          2          1.03125          1"
[1] "0.03125          2          0.0625          0"
[1] "0.0625          2          0.125          0"
[1] "0.125          2          0.25          0"
[1] "0.25          2          0.5          0"
[1] "0.5          2          1          1"
[1] "0          2          0          0"


> sessionInfo()
R version 2.7.2 (2008-08-25) 
i386-pc-mingw32
4

1 回答 1

0

自己发现了...我将粘贴工作代码以供记录。

但是，我遇到了cat()和print()的一个问题，它在行尾给了我不想要的 NULL ......奇怪的是，没有 print 的 cat 会破坏循环。不想。

bin_dec <- function() {

  b <- as.numeric(readline("Input Binary digit: "))

  dec=9999999
  P=9999999
  N=b
  N_list=list()
  bin=list()

  cat("N             B          P             U\n")

  while (!dec%in%N_list[1:length(N_list)-1] & P != 0) {
     P = N*2
     U = floor(P)
     dec = signif(P%%1)
     print(cat(sprintf("%s          2          %s          %s ", N, P, U)))
     N = dec
     N_list <- append(N_list, dec) 
     bin <- append(bin, U)
     }
  dig <- paste(rev(unlist(bin)), collapse = " ")
  cat(paste("\nThe resulting binary digit is:\n\n***", 
            "0 . ", dig, "***\n\n", sep=""))
      }

bin_dec() 

Input Binary digit: 0.21
N             B          P             U
0.21          2          0.42          0 NULL
0.42          2          0.84          0 NULL
0.84          2          1.68          1 NULL
0.68          2          1.36          1 NULL
0.36          2          0.72          0 NULL
0.72          2          1.44          1 NULL
0.44          2          0.88          0 NULL
0.88          2          1.76          1 NULL
0.76          2          1.52          1 NULL
0.52          2          1.04          1 NULL
0.04          2          0.08          0 NULL
0.08          2          0.16          0 NULL
0.16          2          0.32          0 NULL
0.32          2          0.64          0 NULL
0.64          2          1.28          1 NULL
0.28          2          0.56          0 NULL
0.56          2          1.12          1 NULL
0.12          2          0.24          0 NULL
0.24          2          0.48          0 NULL
0.48          2          0.96          0 NULL
0.96          2          1.92          1 NULL
0.92          2          1.84          1 NULL

The resulting binary digit is:

***0 . 1 1 0 0 0 1 0 1 0 0 0 0 1 1 1 0 1 0 1 1 0 0***
于 2013-10-17T18:04:40.657 回答