Removing certain values from a data frame - r

Question

I know there are already some threads like this, but I could not find any solutions.
I have a dataframe that looks like this:
Name Age Sex Survived
1 Allison 0.17 female 1
2 Leah 0.33 female 0
3 David 0.8 male 1
4 Daniel 0.83 male 1
5 Alex 0.83 male 1
6 Jay 0.92 male 1
7 Sara 16 female 1
8 Jade 15 female 1
9 Connor 17 male 1
10 Jon 18 male 1
11 Mary 8 female 1
I want to remove ages that are below 1. I want the data to look like this:
Name Age Sex Survived
1 Allison NA female 1
2 Leah NA female 0
3 David NA male 1
4 Daniel NA male 1
5 Alex NA male 1
6 Jay NA male 1
7 Sara 16 female 1
8 Jade 15 female 1
9 Connor 17 male 1
10 Jon 18 male 1
11 Mary 8 female 1
Or to just remove the rows with ages < 1 altogether.
Following other solutions I tried this but it didn't work
mydata[mydata$Age<"1"&&mydata$Age>"0"] <- NA

Answer 1

Here are three ways to remove the rows:
mydata[mydata$Age > 1, ]
subset(mydata, Age > 1)
filter(mydata, Age > 1)
Here is how to make them NA:
mydata$Age[mydata$Age < 1] <- NA
Your issue is that you are using 1 as a character (in quotes). Character less/greater than work a little differently to numbers so be careful. Also make sure your Age column is numeric. The best way to do that is
mydata$Age <- as.numeric(as.character(mydata$Age))
so you don't accidentally mess up factor variables.
edit
put the wrong signs. fixed now

Answer 2

> mydata[mydata$Age<1, "Age"] <- NA
> mydata
Name Age Sex Survived
1 Allison NA female 1
2 Leah NA female 0
3 David NA male 1
4 Daniel NA male 1
5 Alex NA male 1
6 Jay NA male 1
7 Sara 16 female 1
8 Jade 15 female 1
9 Connor 17 male 1
10 Jon 18 male 1
11 Mary 8 female 1
Update
Maybe you can use if Age is factor
mydata[as.numeric(as.character(mydata$Age))<1, "Age"] <- NA