force R to change contents of a variable

[mmarion]

Is there a way to force a change in variable values in R?

temp  <- replace(mydata4$Age,is.na(mydata4$Age),28)
mydata4$Age <- temp
mydata4$Age

Change is made but when I do following code, NA's are back

names(mydata4)
head(mydata4$Age,20)

#save(mydata4,file="mydata4.Rda")
#df <- load(file="mydata4.Rda")
#df <- as.data.frame(df)
df <- as.data.frame(mydata4)

names(df)
head(df,20)
df$Age
df

Age contains NA's
How to fix?

[FJCC]

I cannot reproduce your result. Does the following code work for you? What is the structure of mydata4 at the beginning of the code?

mydata4 <- data.frame(Age = c(32,61,NA,7), Value =1:4)
mydata4
  Age Value
1  32     1
2  61     2
3  NA     3
4   7     4
temp  <- replace(mydata4$Age,is.na(mydata4$Age),28)
mydata4$Age <- temp
mydata4$Age
[1] 32 61 28  7
names(mydata4)
[1] "Age"   "Value"
head(mydata4$Age,20)
[1] 32 61 28  7
df <- as.data.frame(mydata4)
names(df)
[1] "Age"   "Value"
head(df,20)
  Age Value
1  32     1
2  61     2
3  28     3
4   7     4
df$Age
[1] 32 61 28  7
df
  Age Value
1  32     1
2  61     2
3  28     3
4   7     4

[mmarion]

It turns out that the as.data.frame part of the code is critical that is
df <- as.data.frame(mydata4)

Thanks.
M