Question

我是编程的新手，并且第一次尝试使用R。我实际上是想把一些点放到一个情节中而不能做最简单的事情......

首先：我如何使用如下函数：

coordx<-function(final_distance,radiant){
  x<-(sin(radiant)*final_distance)
  return(x)


xfinal<-coordx(dat$final_distance,dat$radiant)
dat$xfinal<-xfinal
}

我的dataframe dat中没有一些值。

我在第二列radiant中有一些错误的值，需要忽略，但出于统计原因，我不想删除它们。

第二个问题：即使我之前使用过它;什么是从函数结果中创建新列的最简单方法？

我想问这些基本和愚蠢的问题......这是编程中的“第一次尝试”......）

欢呼，史蒂夫

Answer 1

这是一个详细的答案

# Get 10 numbers for final_distance column using sample()
final_distance = sample(1:10)

# Get 10 numbers for radiant column using sample()
    radiant = sample(11:20)

# Create a data frame using the columns final_distance and radiant
    df <- data.frame(final_distance, radiant)

# Write a function 
    coordx<-function(x, y){
      new <-(sin(y) * x)
      return(new)
    }

# Filter the unwanted values in the radiant column
I considered to ignore values that are multiples of 3 (You can write your own criteria)
    df.filtered <- df[df$radiant%%3 != 0,]

# Add new column 'newcol' to data frame 'df' using the above defined function coordx
    df$newcol <- coordx(df.filtered$final_distance, df.filtered$radiant)

# Print the df finally (along with the new column).
    df

根据你最近的评论，我正在添加第二段代码，其中radiant为colu，m为字符串值。

# Get 10 numbers for final_distance column using sample()
final_distance = sample(1:10)

# Get 10 strings for radiant column using sample()
radiant = sample(11:20)

# Another column besides final_distance and radiant that has only strings
Other_column = sample(c("one", "two", "three", "four"), 10, replace = TRUE)

# Create a data frame using the columns final_distance and radiant
df <- data.frame(final_distance, radiant, other_column)

> str(df)
'data.frame':   10 obs. of  3 variables:
 $ final_distance: int  4 3 8 7 5 6 10 1 9 2
 $ radiant       : int  13 16 12 11 19 14 15 18 20 17
 $ other_column  : Factor w/ 4 levels "four","one","three",..: 2 3 2 4 3 2 4 2 1 4

# Write a function 
coordx<-function(x, y){
  new <-(sin(y) * x)
  return(new)
}

# Filter the unwanted values in the radiant column
# I considered to ignore values that are multiples of 3 (You can write your own criteria)
df.filtered <- df[!(df$other_column %in% c("one", "three")), ]

# Add new column 'newcol' to data frame 'df' using the above defined function coordx
df.filtered$newcol <- coordx(df.filtered$final_distance, df.filtered$radiant)

# Print the df finally (along with the new column).
df.filtered

希望，它有所帮助!!

如何忽略data.frame列中的某些值

1 个答案: