Changing variable values in dataframe

General
1

I am attempting to change the variables in NETRTG to be 0 if it is a negative value and 1 if it is a positive value. I have been trying to use a combination of mutate if functions, but having little success. Will take any and all guidance here! Thanks

ID Home Away Team NETRTG
4983535 UCLA Seattle U Seattle U -36.111
4984328 Long Beach St. Seattle U Seattle U -5.212
4984564 Washington Seattle U Seattle U -45.503
4985254 Seattle U Northwest (WA) Seattle U 69.172
4985790 Seattle U Col. of Idaho Seattle U 37.563
4986583 California Seattle U Seattle U -6.2
4986962 Seattle U Portland Seattle U 16.855
4988878 Seattle U Saint Martin's Seattle U 46.131
4989835 Seattle U Utah Valley Seattle U -3.333
4996158 Dixie St. Seattle U Seattle U -4.146
4996988 Dixie St. Seattle U Seattle U 25.034
2

Another way I would actually prefer to do this is create a new column beyond dPTS that compares the PTS and dPTS values for each row. If dPTS is greater, write a 0 in the new column. If PTS is greater, write a 1 in the new column

Home Away Team PTS dPTS
4983535 UCLA Seattle U 52 78
4984328 Long Beach St. Seattle U 75 80
4984564 Washington Seattle U 41 73
4985254 Seattle U Northwest (WA) 89 40
4985790 Seattle U Col. of Idaho 78 54
4986583 California Seattle U 65 70
4986962 Seattle U Portland 84 68
4988878 Seattle U Saint Martin's 98 63
4989835 Seattle U Utah Valley 92 93
4996158 Dixie St. Seattle U 76 77
4996988 Dixie St. Seattle U 77 56
3

This should maybe be it's own thread, but trying to do one more thing to the data of the similar nature. I want to revalue the ID column to the value of Home and Away that is not equal to the Team value for that row. For example,
4983535. UCLA. Seattle U. Seattle U would look like
UCLA. UCLA. Seattle U. Seattle U after the transformation

ID Home Away Team
4983535 UCLA Seattle U Seattle U
4984328 Long Beach St. Seattle U Seattle U
4984564 Washington Seattle U Seattle U
4985254 Seattle U Northwest (WA) Seattle U
4985790 Seattle U Col. of Idaho Seattle U
4986583 California Seattle U Seattle U
4986962 Seattle U Portland Seattle U
4988878 Seattle U Saint Martin's Seattle U
4989835 Seattle U Utah Valley Seattle U
4996158 Dixie St. Seattle U Seattle U
4996988 Dixie St. Seattle U Seattle U
4 
your_df  %>% mutate(your_target = ifelse(your_target <0,0,your_target)
5

Thank you for the reply, but I don't fully understand what is happening there. Could you explain the code and what it is doing. Sorry beginner here

6

Anyone who still doesn't believe in their beginner status (especially me) is delusional.

See the FAQ: How to do a minimal reproducible example reprex for beginners

And come back with a concrete example.

7

Hahaha ok I like that, I will remember that. Here is the minimal reprex

Trying to get the net rating to =1 for positive values and =0 for negative values and then rename the ID variable depending on what the Home and Away variables are set to

CODE:
fdecteamstats=filter(decteamstats, Team == "Seattle U") %>%
mutate(NETRTG >= "0",1) %>%
mutate(NETRTG <= "0",0) %>%
rename(ID = if("Home" != "Seattle U") = "Home", ifelse(= "Away"))

RESULT:
fdecteamstats=filter(decteamstats, Team == "Seattle U") %>%

  • mutate(NETRTG >= "0",1) %>%
  • mutate(NETRTG <= "0",0) %>%
  • rename(ID = if("Home" != "Seattle U") = "Home", ifelse(= "Away"))
    Error: unexpected '=' in:
    " mutate(NETRTG <= "0",0) %>%
    rename(ID = if("Home" != "Seattle U") ="

df [fdecteamstats]

ID Home Away Team Mins oMins dMins oPOSS dPOSS ORTG DRTG NETRTG PTS dPTS
4983535 UCLA Seattle U Seattle U 38.683 19.6 19.083 72 72 72.222 108.333 -36.111 52 78
4984328 Long Beach St. Seattle U Seattle U 38.167 21.633 16.533 76 77 98.684 103.896 -5.212 75 80
4984564 Washington Seattle U Seattle U 38.683 21.083 17.6 68 69 60.294 105.797 -45.503 41 73
4985254 Seattle U Northwest (WA) Seattle U 39.183 16.417 22.767 70 69 127.143 57.971 69.172 89 40
4985790 Seattle U Col. of Idaho Seattle U 39.183 19.067 20.117 68 70 114.706 77.143 37.563 78 54
4986583 California Seattle U Seattle U 39.083 19.867 19.217 63 64 103.175 109.375 -6.2 65 70
4986962 Seattle U Portland Seattle U 39.917 20.85 19.067 79 76 106.329 89.474 16.855 84 68
4988878 Seattle U Saint Martin's Seattle U 38.817 18 20.817 74 73 132.432 86.301 46.131 98 63
4989835 Seattle U Utah Valley Seattle U 43.583 22.717 20.867 92 90 100 103.333 -3.333 92 93
4996158 Dixie St. Seattle U Seattle U 39.767 20.767 19 75 73 101.333 105.479 -4.146 76 77
4996988 Dixie St. Seattle U Seattle U 39.483 21.633 17.85 78 76 98.718 73.684 25.034 77 56
8

I know we have a homeless problem in SEA.

suppressPackageStartupMessages({
  library(dplyr)
})
decteamstats <- data.frame(
  me =
    c(4983535, 4984328, 4984564, 4985254, 4985790, 4986583, 4986962, 4988878, 4989835, 4996158, 4996988),
  Away =
    c("UCLA", "Long Beach St.", "Washington", "Seattle U", "Seattle U", "California", "Seattle U", "Seattle U", "Seattle U", "Dixie St.", "Dixie St."),
  Team =
    c("Seattle U", "Seattle U", "Seattle U", "Northwest (WA)", "Col. of Idaho", "Seattle U", "Portland", "Saint Martin's", "Utah Valley", "Seattle U", "Seattle U"),
  Mins =
    c("Seattle U", "Seattle U", "Seattle U", "Seattle U", "Seattle U", "Seattle U", "Seattle U", "Seattle U", "Seattle U", "Seattle U", "Seattle U"),
  oMins =
    c(38.683, 38.167, 38.683, 39.183, 39.183, 39.083, 39.917, 38.817, 43.583, 39.767, 39.483),
  dMins =
    c(19.6, 21.633, 21.083, 16.417, 19.067, 19.867, 20.85, 18, 22.717, 20.767, 21.633),
  oPOSS =
    c(19.083, 16.533, 17.6, 22.767, 20.117, 19.217, 19.067, 20.817, 20.867, 19, 17.85),
  dPOSS =
    c(72, 76, 68, 70, 68, 63, 79, 74, 92, 75, 78),
  ORTG =
    c(72, 77, 69, 69, 70, 64, 76, 73, 90, 73, 76),
  DRTG =
    c(72.222, 98.684, 60.294, 127.143, 114.706, 103.175, 106.329, 132.432, 100, 101.333, 98.718),
  NETRTG =
    c(108.333, 103.896, 105.797, 57.971, 77.143, 109.375, 89.474, 86.301, 103.333, 105.479, 73.684),
  PTS =
    c(-36.111, -5.212, -45.503, 69.172, 37.563, -6.2, 16.855, 46.131, -3.333, -4.146, 25.034),
  dPTS =
    c(52, 75, 41, 89, 78, 65, 84, 98, 92, 76, 77)
)
9

Yes we do, as any big city does. Something needs to be done though to help!

I ran that line of code:

"
fdecteamstats=filter(decteamstats, Team == "Seattle U") %>%
rename(ID = if("Home" != "Seattle U") = "Home", ifelse(= "Away"))
"
And still got the error
Error: unexpected '=' in:
"fdecteamstats=filter(decteamstats, Team == "Seattle U") %>%
rename(ID=if("Home" != "Seattle U")="

What is not correct there?

11

Our homeless problem is worse than other cities, by the standards we hold ourselves to.

The problem is that there is no variable Home. And if there were, it shouldn't be quoted.

12

The problem is that R uses a single = as an attribution sign. If you want to compare something, use double ==.

Another thing that I noticed is with the mutate. You were trying to compare your variable with a character value.
You can change the variable with a simple mutate:

decteamstats  %>% mutate(NETRTG = ifelse(NETRTG <= 0, 1, 0)

I don't actually understand what you are trying to achieve with the rename part of the code, change the value of the variable or rename the variable.

If you can be a bit more explicit with that part I can try and help you.

13

the problem with

is too many to list ... but the easy point to make is that its substantially not what technocrat recommended you try which was syntax of the form

your_df %>% mutate(your_target = ifelse(your_target <0,0,your_target)

I think you may have been confused because technocrat quoted your incorrect syntax in the post in which he provides example data ...

1 Like
14

Thank you! I was really struggling to convert the help I was getting into successful code, but the mutate on NETRTG is now working perfectly!

What I am trying to do with the rename of the code is to change the ID variable in each row to be the Home or Away value as long as it is not "Seattle U". I am trying to make the ID become the team name that is not Seattle U.

For example, after the rename I want row 1 to go from
4998535 UCLA Seattle U Seattle U to
UCLA UCLA Seattle U Seattle U

ID Home Away Team
4983535 UCLA Seattle U Seattle U
4984328 Long Beach St. Seattle U Seattle U
4984564 Washington Seattle U Seattle U
4985254 Seattle U Northwest (WA) Seattle U
4985790 Seattle U Col. of Idaho Seattle U
4986583 California Seattle U Seattle U
4986962 Seattle U Portland Seattle U
4988878 Seattle U Saint Martin's Seattle U
4989835 Seattle U Utah Valley Seattle U
4996158 Dixie St. Seattle U Seattle U
4996988 Dixie St. Seattle U Seattle U
15

where df is your data

mutate(rowwise(df),
       ID= (setdiff(c(Home,Away),Team)))

p.s. although markdown tables are nice ways to present tabular information to the reader of a forum post, they are a bad way to share example data, as it is non-trivial for a typical forum user to bring the data into their R session. Therefore please consider studying the reprex guide (which is a short read) to understand the preferred methods of sharing example data on the forum.

16

Ok thank you so much! That worked and I will look at the reprex guide and do it that way moving forward. I can get the code to run correctly as it's own step, but when I try to group it in with other lines of code it doesn't work. I don't understand the error message I am getting. Do you see what is happening wrong?

fdecteamstats=filter(decteamstats, Team == "Seattle U") %>%
  mutate("NETRTG" = ifelse(NETRTG <= 0, 0, 1)) %>%
  mutate_if(is.numeric, round) %>%
  rename("W/L" = NETRTG) %>%
  mutate("Home" = ifelse(Home == "Seattle U", 1, 0)) %>%
  mutate(rowwise(fdecteamstats),
         ID= (setdiff(c(Home,Away),Team)))

And the error I am getting back is

Error: Problem with `mutate()` input `..1`.
x Input `..1` can't be recycled to size 1.
ℹ Input `..1` is `rowwise(fdecteamstats)`.
ℹ Input `..1` must be size 1, not 11.
ℹ The error occurred in group 1: ID = 4983535, Home = 0, Away = "Seattle U"

I would assume that I would need to take (fdecteamstats) out because it is already set on the correct df from abov, but am not sure.

17

you do want the data.frame to be process rowwise, but you are setting rowwise on a dataframe that logically wont exist untill the series of pipes complete. its sufficient to add rowwise as an operation between other operations

%>% rowwise() %>% mutate(ID = ... etc.)
18

I am still running to an error for some reason

fdecteamstats=filter(decteamstats, Team == "Seattle U") %>%
  mutate("NETRTG" = ifelse(NETRTG <= 0, 0, 1)) %>%
  mutate_if(is.numeric, round) %>%
  rename("W/L" = NETRTG) %>%
  mutate("Home" = ifelse(Home == "Seattle U", 1, 0)) %>%
  rowwise() %>%
  ID = (setdiff(c("Home","Away"),"Team"))

> fdecteamstats=filter(decteamstats, Team == "Seattle U") %>%
+   mutate("NETRTG" = ifelse(NETRTG <= 0, 0, 1)) %>%
+   mutate_if(is.numeric, round) %>%
+   rename("W/L" = NETRTG) %>%
+   mutate("Home" = ifelse(Home == "Seattle U", 1, 0)) %>%
+   rowwise() %>%
+   ID= (setdiff(c("Home","Away"),"Team"))
`mutate_if()` ignored the following grouping variables:
Columns `ID`, `Home`, `Away`
Error in filter(decteamstats, Team == "Seattle U") %>% mutate(NETRTG = ifelse(NETRTG <=  : 
  could not find function "%>%<-"

It is saying it can't find the function "%>%<-" but I don't see that in any line of my code so I am confused

19

You omitted the mutate ( that gives setting ID to some value context.

20

:roll_eyes: I feel like an idiot. I am an absolute self taught beginner if you can't tell.

  mutate("NETRTG" = ifelse(NETRTG <= 0, 0, 1)) %>%
  mutate_if(is.numeric, round) %>%
  rename("W/L" = NETRTG) %>%
  mutate("Home" = ifelse(Home == "Seattle U", 1, 0)) %>%
  rowwise() %>%
  mutate("ID" = (setdiff(c("Home","Away"),"Team")))

I am still getting an error though?

Error: Problem with `mutate()` input `ID`.
x Input `ID` can't be recycled to size 1.
ℹ Input `ID` is `(setdiff(c("Home", "Away"), "Team"))`.
ℹ Input `ID` must be size 1, not 2.
ℹ Did you mean: `ID = list((setdiff(c("Home", "Away"), "Team")))` ?
ℹ The error occurred in row 1.

I have tried having ID both in quotes and not in quotes

21

You introduced quotes around home team away to make them literal, when they rather should be unquoted and represent columns in your frame