Retrieving corresponding column values based on row label [duplicate] - r

I have a data frame, str(data) to show more about my data frame the result is the following:
> str(data)
'data.frame': 153 obs. of 6 variables:
$ Ozone : int 41 36 12 18 NA 28 23 19 8 NA ...
$ Solar.R: int 190 118 149 313 NA NA 299 99 19 194 ...
$ Wind : num 7.4 8 12.6 11.5 14.3 14.9 8.6 13.8 20.1 8.6 ...
$ Temp : int 67 72 74 62 56 66 65 59 61 69 ...
$ Month : int 5 5 5 5 5 5 5 5 5 5 ...
$ Day : int 1 2 3 4 5 6 7 8 9 10 ...
However, for example, when I want to subset the amounts of Ozone above 14 I use the following code which gives me an error:
> data[data$Ozone > 14 ]
Error in [.data.frame(data, data$Ozone > 14) : undefined columns selected

You want rows where that condition is true so you need a comma:
data[data$Ozone > 14, ]

Related

List being added to a dataframe

Why is a list being added to my dataframe here?
Here's my dataframe
df <- data.frame(ch = rep(1:10, each = 12), # care home id
year_id = rep(2018),
month_id = rep(1:12), # month using the system over the course of a year (1 = first month, 2 = second month...etc.)
totaladministrations = rbinom(n=120, size = 1000, prob = 0.6), # administrations that were scheduled to have been given in the month
missed = rbinom(n=120, size = 20, prob = 0.8), # administrations that weren't given in the month (these are bad!)
beds = rep(rbinom(n = 10, size = 60, prob = 0.6), each = 12), # number of beds in the care home
rating = rep(rbinom(n= 10, size = 4, prob = 0.5), each = 12)) # latest inspection rating (1. Inadequate, 2. Requires Improving, 3. Good, 4 Outstanding)
df <- arrange(df, df$ch, df$year_id, df$month_id)
str(df)
> str(df)
'data.frame': 120 obs. of 7 variables:
$ ch : int 1 1 1 1 1 1 1 1 1 1 ...
$ year_id : num 2018 2018 2018 2018 2018 ...
$ month_id : int 1 2 3 4 5 6 7 8 9 10 ...
$ totaladministrations: int 576 598 608 576 608 637 611 613 593 626 ...
$ missed : int 18 18 19 16 16 13 17 16 15 17 ...
$ beds : int 38 38 38 38 38 38 38 38 38 38 ...
$ rating : int 2 2 2 2 2 2 2 2 2 2 ...
All good so far.
I just want to add another column that sequences the month number within the ch group (this equates to the actual month_id in this example but ignore that, my real life data is different), so I'm using:
df <- df %>% group_by(ch) %>%
mutate(sequential_month_counter = 1:n())
This appears to add a bunch stuff I don't really understand or want or need, such as a list ...
str(df)
> str(df)
Classes ‘grouped_df’, ‘tbl_df’, ‘tbl’ and 'data.frame': 120 obs. of 8 variables:
$ ch : int 1 1 1 1 1 1 1 1 1 1 ...
$ year_id : num 2018 2018 2018 2018 2018 ...
$ month_id : int 1 2 3 4 5 6 7 8 9 10 ...
$ totaladministrations : int 601 590 593 599 615 611 628 587 604 600 ...
$ missed : int 16 14 17 16 18 16 15 18 15 20 ...
$ beds : int 35 35 35 35 35 35 35 35 35 35 ...
$ rating : int 3 3 3 3 3 3 3 3 3 3 ...
$ sequential_month_counter: int 1 2 3 4 5 6 7 8 9 10 ...
- attr(*, "groups")=Classes ‘tbl_df’, ‘tbl’ and 'data.frame': 10 obs. of 2 variables:
..$ ch : int 1 2 3 4 5 6 7 8 9 10
..$ .rows:List of 10
.. ..$ : int 1 2 3 4 5 6 7 8 9 10 ...
.. ..$ : int 13 14 15 16 17 18 19 20 21 22 ...
.. ..$ : int 25 26 27 28 29 30 31 32 33 34 ...
.. ..$ : int 37 38 39 40 41 42 43 44 45 46 ...
.. ..$ : int 49 50 51 52 53 54 55 56 57 58 ...
.. ..$ : int 61 62 63 64 65 66 67 68 69 70 ...
.. ..$ : int 73 74 75 76 77 78 79 80 81 82 ...
.. ..$ : int 85 86 87 88 89 90 91 92 93 94 ...
.. ..$ : int 97 98 99 100 101 102 103 104 105 106 ...
.. ..$ : int 109 110 111 112 113 114 115 116 117 118 ...
..- attr(*, ".drop")= logi TRUE
What's going on here? I just want a dataframe. Why is there all that additional output after $ sequential_month_counter: int 1 2 3 4 5 6 7 8 9 10 ... and more importantly can I ignore it and just keep treating it as a normal dataframe (i'll be running some generalised linear mixed models on the df)?
The attribute "groups" is where dplyr stores the grouping information added when you did group_by(ch). It doesn't hurt anything, and it will disappear if you ungroup():
df %>% group_by(ch) %>%
mutate(sequential_month_counter = 1:n()) %>%
ungroup %>%
str
# Classes ‘tbl_df’, ‘tbl’ and 'data.frame': 120 obs. of 8 variables:
# $ ch : int 1 1 1 1 1 1 1 1 1 1 ...
# $ year_id : num 2018 2018 2018 2018 2018 ...
# $ month_id : int 1 2 3 4 5 6 7 8 9 10 ...
# $ totaladministrations : int 575 597 579 605 582 599 577 604 630 632 ...
# $ missed : int 18 16 16 18 18 11 10 13 17 16 ...
# $ beds : int 33 33 33 33 33 33 33 33 33 33 ...
# $ rating : int 3 3 3 3 3 3 3 3 3 3 ...
# $ sequential_month_counter: int 1 2 3 4 5 6 7 8 9 10 ...
As a side-note, you should use bare column names inside dplyr verbs, not data$column. With arrange, it doesn't much matter, but in grouped operations it will cause bugs. You should get in the habit of using arrange(df, ch, year_id, month_id) instead of arrange(df, df$ch, df$year_id, df$month_id).

Unable to designate CSV column heads "as.factor" for R -Error

I am having an issue with assigning factors to my data CSV. Here is a summary of the data frame:
> data.frame': 303 obs. of 12 variables:
> PLOT : int 19 177 54 114 41 48 142 134 160 267 ...
> RANGE : int 2 12 4 8 3 4 10 9 11 18 ...
> ROW : int 4 12 9 9 11 3 7 14 10 12 ...
> REP : int 1 1 1 1 1 1 1 1 1 1 ...
> ENTRY : Factor w/ 184 levels "","17_YMG_0293",..: 40 40 77 82 87 88 102 103 103 6 ...
> PLOT_ID : Factor w/ 301 levels "","18_HZG_OvOv_001",..: 20 178 55 115 42 49 143 135 161 268 ...
> Shatter : num 9 9 9 9 9 9 9 9 9 8 ...
> Chaff.Color : Factor w/ 4 levels "","*Blank ones are segregating in color",..: 3 4 3 4 4 4 3 4 4 3 ...
> Heading_d.from.Jan.1: int 138 139 137 133 135 135 133 137 135 136 ...
> Height_cm : int 74 73 77 76 74 79 78 73 76 70 ...
> Plot.weight..kg. : num 0.26 0.18 0.19 0.14 0.33 0.19 0.13 0.11 0.24 0.18 ...
But I get this error:
HAYSData$Rep<-as.factor(HAYSData$Rep)
Error in `$<-.data.frame`(`*tmp*`, Rep, value = integer(0)) :
replacement has 0 rows, data has 303
I get the same type of error for Entry, Range, and Rows. I am not sure when I look at length(Entry) for example I get 300. I even tested with changing factor to numeric but it does not help.
I don't have an NA in my data each category is its own column as well.
I don't know if something is wrong with my CSV. I have worked this same script with another CSV but no issues in the part of the script for the other data.
Can someone please help me?
It's case-sensitive, try with:
HAYSData$REP <- as.factor(HAYSData$REP)
HAYSData$ENTRY <- as.factor(HAYSData$ENTRY)
HAYSData$RANGE <- as.factor(HAYSData$RANGE)
HAYSData$ROW <- as.factor(HAYSData$ROW)

Error in ncol(xj) : object 'xj' not found when using R matplot()

Using matplot, I'm trying to plot the 2nd, 3rd and 4th columns of airquality data.frame after dividing these 3 columns by the first column of airquality.
However I'm getting an error
Error in ncol(xj) : object 'xj' not found
Why are we getting this error? The code below will reproduce this problem.
attach(airquality)
airquality[2:4] <- apply(airquality[2:4], 2, function(x) x /airquality[1])
matplot(x= airquality[,1], y= as.matrix(airquality[-1]))
You have managed to mangle your data in an interesting way. Starting with airquality before you mess with it. (And please don't attach() - it's unnecessary and sometimes dangerous/confusing.)
str(airquality)
'data.frame': 153 obs. of 6 variables:
$ Ozone : int 41 36 12 18 NA 28 23 19 8 NA ...
$ Solar.R: int 190 118 149 313 NA NA 299 99 19 194 ...
$ Wind : num 7.4 8 12.6 11.5 14.3 14.9 8.6 13.8 20.1 8.6 ...
$ Temp : int 67 72 74 62 56 66 65 59 61 69 ...
$ Month : int 5 5 5 5 5 5 5 5 5 5 ...
$ Day : int 1 2 3 4 5 6 7 8 9 10 ...
After you do
airquality[2:4] <- apply(airquality[2:4], 2,
function(x) x /airquality[1])
you get
'data.frame': 153 obs. of 6 variables:
$ Ozone : int 41 36 12 18 NA 28 23 19 8 NA ...
$ Solar.R:'data.frame': 153 obs. of 1 variable:
..$ Ozone: num 4.63 3.28 12.42 17.39 NA ...
$ Wind :'data.frame': 153 obs. of 1 variable:
..$ Ozone: num 0.18 0.222 1.05 0.639 NA ...
$ Temp :'data.frame': 153 obs. of 1 variable:
..$ Ozone: num 1.63 2 6.17 3.44 NA ...
$ Month : int 5 5 5 5 5 5 5 5 5 5 ...
$ Day : int 1 2 3 4 5 6 7 8 9 10 ...
or
sapply(airquality,class)
## Ozone Solar.R Wind Temp Month Day
## "integer" "data.frame" "data.frame" "data.frame" "integer" "integer"
that is, you have data frames embedded within your data frame!
rm(airquality) ## clean up
Now change one character and divide by the column airquality[,1] rather than airquality[1] (divide by a vector, not a list of length one ...)
airquality[,2:4] <- apply(airquality[,2:4], 2,
function(x) x/airquality[,1])
matplot(x= airquality[,1], y= as.matrix(airquality[,-1]))
In general it's safer to use [, ...] indexing rather than [] indexing to refer to columns of a data frame unless you really know what you're doing ...

Data extraction in R

I have a data set data with structure as
'data.frame': 153 obs. of 6 variables:
$ Ozone : int 41 36 12 18 NA 28 23 19 8 NA ...
$ Solar.R: int 190 118 149 313 NA NA 299 99 19 194 ...
$ Wind : num 7.4 8 12.6 11.5 14.3 14.9 8.6 13.8 20.1 8.6 ...
$ Temp : int 67 72 74 62 56 66 65 59 61 69 ...
$ Month : int 5 5 5 5 5 5 5 5 5 5 ...
$ Day : int 1 2 3 4 5 6 7 8 9 10 ...
Now when want to remove NA from the column Ozone the following way is showing me an error :
mean(data["Ozone"], na.rm = TRUE)
[1] NA
Warning message:
In mean.default(data["Ozone"], na.rm = TRUE) :
argument is not numeric or logical: returning NA
How should I remove NA in the above problem?
You forgot a comma when subseting, just include that missing comma and it'll work like a charm
> mean(data[, "Ozone"], na.rm = TRUE)
[1] 42.12931
I'm assuming you are working with airquality dataset.
Note that double brakets (without comma) also works
> mean(data[["Ozone"]], na.rm = TRUE)
[1] 42.12931
Take a look at ?Extract for further details on subseting.

Undefined columns selected when subsetting data frame

I have a data frame, str(data) to show more about my data frame the result is the following:
> str(data)
'data.frame': 153 obs. of 6 variables:
$ Ozone : int 41 36 12 18 NA 28 23 19 8 NA ...
$ Solar.R: int 190 118 149 313 NA NA 299 99 19 194 ...
$ Wind : num 7.4 8 12.6 11.5 14.3 14.9 8.6 13.8 20.1 8.6 ...
$ Temp : int 67 72 74 62 56 66 65 59 61 69 ...
$ Month : int 5 5 5 5 5 5 5 5 5 5 ...
$ Day : int 1 2 3 4 5 6 7 8 9 10 ...
However, for example, when I want to subset the amounts of Ozone above 14 I use the following code which gives me an error:
> data[data$Ozone > 14 ]
Error in [.data.frame(data, data$Ozone > 14) : undefined columns selected
You want rows where that condition is true so you need a comma:
data[data$Ozone > 14, ]

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