R, dplyr: How to divide date frame elements by specific elements - r

edit: Solution at the end.
I have a dataframe that contains different variables and the sum of these different variables as a variable called "total".
I want to add a new column that calculates each variables' share of the "total"-variable.
Example:
library(dplyr)
name <- c('A','A',
'B','B')
month = c("oct 2018", "nov 2018",
"oct 2018", "nov 2018")
value <- seq(1:length(month))
df = data.frame(name, month, value)
# Create total variable
dfTotal =
df%>%
group_by_("month")%>%
summarize(value = sum(value, na.rm = TRUE))
dfTotal[["name"]] <- "Total"
dfTotal = as.data.frame(dfTotal)
# Add total column to dataframe
df2 = rbind(df, dfTotal)
df2
which gives the dataframe
name month value
1 A oct 2018 1
2 A nov 2018 2
3 B oct 2018 3
4 B nov 2018 4
5 Total nov 2018 6
6 Total oct 2018 4
What I want is to produce a new column with the shares of the total for each month in the above dataframe, so that I get something like
name month value share
1 A oct 2018 1 0.25 (=1/4)
2 A nov 2018 2 0.33 (=2/6)
3 B oct 2018 3 0.75 (=3/4)
4 B nov 2018 4 0.67 (=4/6)
5 Total nov 2018 6 1.00 (=6/6)
6 Total oct 2018 4 1.00 (=4/4)
Does anybody know how I from the first dataframe can produce the last column in the second dataframe?
Solution:
Based on tmfmnk's comment, the following solves the problem:
df2 =
df2 %>%
group_by(month) %>%
mutate(share = value/max(value))
df2
which gives
name month value share
<fct> <fct> <int> <dbl>
1 A oct 2018 1 0.25
2 A nov 2018 2 0.333
3 B oct 2018 3 0.75
4 B nov 2018 4 0.667
5 Total nov 2018 6 1
6 Total oct 2018 4 1

Related

Two line graphs in the same plot in R

I have a large dataframe. i am trying to plot sales for 2 different years in the same plots as line graph to show the variation across 2 years each month. There is a long series of grouping and filtering i have done before getting the below dataframe.
Dataframe has 3 columns (month, sales and the year)
When I am trying to plot the sales across the different years as :
ggplot(df,aes(x=month.sales,y=sales/100000,color=year)) +
geom_line()
I am getting a blank graph with x and y labels , while if I plot a column graph, it works.
Please help.
thank you
I'm guessing your data looks something like this:
set.seed(69)
df <- data.frame(month.sales = factor(rep(month.abb, 2), month.abb),
year = rep(2018:2019, each = 12),
sales = runif(24, 1, 2) * 100000)
df
#> month.sales year sales
#> 1 Jan 2018 114570.1
#> 2 Feb 2018 123197.1
#> 3 Mar 2018 166092.7
#> 4 Apr 2018 163214.1
#> 5 May 2018 109486.6
#> 6 Jun 2018 131429.8
#> 7 Jul 2018 167363.6
#> 8 Aug 2018 191097.6
#> 9 Sep 2018 127427.4
#> 10 Oct 2018 145360.1
#> 11 Nov 2018 134577.1
#> 12 Dec 2018 169486.6
#> 13 Jan 2019 168493.2
#> 14 Feb 2019 147552.5
#> 15 Mar 2019 139811.3
#> 16 Apr 2019 156351.2
#> 17 May 2019 199368.3
#> 18 Jun 2019 130953.6
#> 19 Jul 2019 148150.5
#> 20 Aug 2019 166307.3
#> 21 Sep 2019 121830.8
#> 22 Oct 2019 101838.1
#> 23 Nov 2019 109716.9
#> 24 Dec 2019 125407.9
In which case you can draw a line plot like this:
library(ggplot2)
ggplot(df, aes(x = month.sales, y = sales / 100000,
color = factor(year), group = factor(year))) +
geom_line()
Note that you need to add the group aesthetic so that ggplot doesn't automatically group your data points according to the factor levels on the x axis.

How to rearrange daily stream discharge data into monthly format and rank the discharge values for each month using R

I have a data set of daily stream discharge values from a gauging station for approximately 50 years. The data is arranged into three columns, namely, "date", "month", "discharge".(Sample data shown here)
`
Date<- as.Date(c('1938-10-01','1954-10-27', '1967-06-16','1943-01-01','1945-01-14','1945-03-14','1954-05-04','1960-04-23','1960-05-09','1962-01-18','1968-12-19','1972-01-15','1977-08-15','1981-04-11','1986-06-20','1989-01-20','1992-03-29'))
> Months<- c('Oct','Oct','Jun','Jan','Jan','Mar','May','Apr','May','Jan','Dec','Jan','Aug','Apr','Jun','Jan','Mar')
> Dis<-c('1000','1200','400','255','450','215','360','120','145','1204','752','635','1456','154','154','1204','450')
> Sampledata<-data.frame("Date"=Date,"Months"=Months,"Disch"=Dis)
> print(Sampledata)
Date Months Disch
1 1938-10-01 Oct 1000
2 1954-10-27 Oct 1200
3 1967-06-16 Jun 400
4 1943-01-01 Jan 255
5 1945-01-14 Jan 450
6 1945-03-14 Mar 215
7 1954-05-04 May 360
8 1960-04-23 Apr 120
9 1960-05-09 May 145
10 1962-01-18 Jan 1204
11 1968-12-19 Dec 752
12 1972-01-15 Jan 635
13 1977-08-15 Aug 1456
14 1981-04-11 Apr 154
15 1986-06-20 Jun 154
16 1989-01-20 Jan 1204
17 1992-03-29 Mar 450
I want to calculate ranks for each month separately for all the years. For example: Calculate rank in ascending order for the month of January for 50 years. With the same rank value assigned to a duplicate discharge value. Desired output shown here:
> Date Month Disch Rank
1 1943-01-01 Jan 255 1
2 1945-01-14 Jan 450 2
3 1962-01-18 Jan 1204 4
4 1972-01-15 Jan 635 3
5 1989-01-20 Jan 1204 4
> Date Month Disch Rank
1 1945-03-14 Mar 215 1
2 1992-03-29 Mar 450 2
3 2001-03-19 Mar 450 2
Without using any packages first convert columns 2 and 3 to numeric and then use ave and rank with the indicated ties method. Finally order the result.
Note that the output shown in the question does not correspond to the input, e.g. there are three Mar rows in the output but only two such rows in the input so this will correspond to the input but will not be identical to the output shown.
Sampledata2 <- transform(Sampledata,
Disch = as.numeric(as.character(Disch)),
Months = as.numeric(format(Date, "%m")))
Rank <- function(x) rank(x, ties = "min")
Sampledata3 <- transform(Sampledata2,
Rank = ave(Disch, Months, FUN = Rank))
o <- with(Sampledata3, order(Months, Date))
Sampledata3[o, ]
An option would be to group by 'Month' and use one of the ranking functions (dense_rank, row_number(), min_rank - based on the needs) to rank the 'Discharge' column
library(dplyr)
df1 %>%
group_by(Month) %>%
mutate(Rank = dense_rank(Discharge))

Divide 2 columns from 2 different dataframes

Does anybody know how to divide two columns from two different dataframes when there are multiple columns to id from?
Example:
library(dplyr)
name <- c('A','A',
'B','B')
month = c("oct 2018", "nov 2018",
"oct 2018", "nov 2018")
var1 = c("99", "99",
"99", "99")
value <- seq(1:length(month))
df1 = data.frame(name, month, var1, value)
df2 = df1
df2["var1"] = c("992", "992", "992", "992")
df2["value"] = c(2, 4, 6, 8)
df1
df2
Output
> df1
name month var1 value
1 A oct 2018 99 1
2 A nov 2018 99 2
3 B oct 2018 99 3
4 B nov 2018 99 4
> df2
name month var1 value
1 A oct 2018 992 2
2 A nov 2018 992 4
3 B oct 2018 992 6
4 B nov 2018 992 8
Does anybody know how to create a new dataframe that divides the "value"-column in df2 by the value column of df1? The method should be possible to use also when there are more columns than in the current example.
In base R, we can do merge
df3 <- merge(df1, df2, by = c("name", "month"))
df3$value <- df3$value.x/df3$value.y
df3
# name month var1.x value.x var1.y value.y value
#1 A nov 2018 99 2 992 4 0.5
#2 A oct 2018 99 1 992 2 0.5
#3 B nov 2018 99 4 992 8 0.5
#4 B oct 2018 99 3 992 6 0.5
You can drop value.x and value.y column if they are not needed.
Join the two data frames together and then perform the division and drop unwanted columns that were generated by the join (assuming you want computed value column to replace the value columns from the original data frames). Depending on what you want you may need a different *_join.
library(dplyr)
df1 %>%
inner_join(df2, by = c("name", "month")) %>%
mutate(value = value.x / value.y) %>%
select(-value.x, -value.y)
giving:
name month var1.x var1.y value
1 A oct 2018 99 992 0.5
2 A nov 2018 99 992 0.5
3 B oct 2018 99 992 0.5
4 B nov 2018 99 992 0.5
We can use data.table as well to do a join and create the column 'value' by dividing the 'value' column by the corresponding column in the other dataset while joining on 'name' and 'month'
library(data.table)
df3 <- copy(df1)
setDT(df3)[df2, value := value/i.value, on = .(name, month)]
df3
# name month var1 value
#1: A oct 2018 99 0.5
#2: A nov 2018 99 0.5
#3: B oct 2018 99 0.5
#4: B nov 2018 99 0.5

Use dplyr/tidyr to turn rows into columns in R data frame

I have a data frame like this:
year <-c(floor(runif(100,min=2015, max=2017)))
month <- c(floor(runif(100, min=1, max=13)))
inch <- c(floor(runif(100, min=0, max=10)))
mm <- c(floor(runif(100, min=0, max=100)))
df = data.frame(year, month, inch, mm);
year month inch mm
2016 11 0 10
2015 9 3 34
2016 6 3 33
2015 8 0 77
I only care about the columns year, month, and mm.
I need to re-arrange the data frame so that the first column is the name of the month and the rest of the columns is the value of mm.
Months 2015 2016
Jan # #
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
So two things needs to happen.
(1) The month needs to become a string of the first three letters of the month.
(2) I need to group by year, and then put the mm values in a column under that year.
So far I have this code, but I can't figure it out:
df %>%
select(-inch) %>%
group_by(month) %>%
summarize(mm = mm) %>%
ungroup()
To convert month to names, you can refer to month.abb; And then you can summarize by year and month, spread to wide format:
library(dplyr)
library(tidyr)
df %>%
group_by(year, month = month.abb[month]) %>%
summarise(mm = mean(mm)) %>% # use mean as an example, could also be sum or other
# intended aggregation methods
spread(year, mm) %>%
arrange(match(month, month.abb)) # rearrange month in chronological order
# A tibble: 12 x 3
# month `2015` `2016`
# <chr> <dbl> <dbl>
# 1 Jan 65.50000 28.14286
# 2 Feb 54.40000 30.00000
# 3 Mar 23.50000 95.00000
# 4 Apr 7.00000 43.60000
# 5 May 45.33333 44.50000
# 6 Jun 70.33333 63.16667
# 7 Jul 72.83333 52.00000
# 8 Aug 53.66667 66.50000
# 9 Sep 51.00000 64.40000
#10 Oct 74.00000 39.66667
#11 Nov 66.20000 58.71429
#12 Dec 38.25000 51.50000

How do I update data from an incomplete lookup table?

I have a table that uses unique IDs but inconsistent readable names for those IDs. It is more complex than month names, but for the sake of a more simple example, let's say it looks something like this:
demo_frame <- read.table(text=" Month_id Month_name Number
1 Jan 37
2 Feb 63
3 March 9
3 Mar 150
2 February 49", header=TRUE)
Except that they might have spelled "Feb" or "March" eight different ways. I also have a clean data frame that contains consistent names for the names that have variations:
month_lookup <- read.table(text=" Month_id Month_name
2 Feb
3 Mar", header=TRUE)
I want to get to this:
1 Jan 37
2 Feb 63
3 Mar 9
3 Mar 150
2 Feb 49"
I tried merge(month_lookup, demo_frame, by = "Month_id") but that dropped all the January values because "Jan" doesn't exist in the lookup table:
Month_id Month_name.x Month_name.y Number
1 2 Feb Feb 63
2 2 Feb February 49
3 3 Mar March 9
4 3 Mar Mar 150
My read of How to replace data.frame column names with string in corresponding lookup table in R is that I ought to be able to use plyr::mapvalues but I'm unclear from examples and documentation on how I'd map the id to the name. I don't just want to say "Replace 'March' with 'Mar'" -- I need to say SET month_name = 'Mar' WHERE month_id = 3 for each value in lookup.
I think you want this.
library(dplyr)
demo_frame <- read.table(text=" Month_id Month_name Number
1 Jan 37
2 Feb 63
3 March 9
3 Mar 150
2 February 49", header=TRUE, stringsAsFactors = FALSE)
month_lookup <- read.table(text=" Month_id Month_name
2 Feb
3 Mar", header=TRUE, stringsAsFactors = FALSE)
result =
demo_frame %>%
rename(bad_month = Month_name) %>%
left_join(month_lookup) %>%
mutate(month_fix =
Month_name %>%
is.na %>%
ifelse(bad_month, Month_name) )

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