dataframe

问题 Suppose I want to select a range of columns from a dataframe: Call them 'column_1' through 'column_60'. I know I could use loc like this: df.loc[:, 'column_1':'column_60'] That will give me all rows in columns 1-60. But what if I wanted that range of columns plus 'column_81'. This doesn't work: df.loc[:, 'column_1':'column_60', 'column_81'] It throws a "Too many indexers" error. Is there another way to state this using loc? Or is loc even the best function to use in this case? Many thanks.

问题 I'm using Julia's DataFrames.jl package. In it, I have a dataframe with a columns containing a list of strings (e.g. ["Type A", "Type B", "Type D"]). How does one then performs a one-hot encoding? I wasn't able to find a pre-built function in the DataFrames.jl package. Here is an example of what I want to do: Original Dataframe col1 | col2 | 102 |[a] | 103 |[a,b] | 102 |[c,b] | After One-hot encoding col1 | a | b | c | 102 | 1 | 0 | 0 | 103 | 1 | 1 | 0 | 102 | 0 | 1 | 1 | 回答1: It is easy

问题 I have a DataFrame to which I need to add a column. The column needs to be a list of two values: Current table: lat long other_value 0 50 50 x 1 60 50 y 2 70 50 z 3 80 50 a Needed table: lat long other_value new_column 0 50 50 x [50, 50] 1 60 50 y [60, 50] 2 70 50 z [70, 50] 3 80 50 a [80, 50] I know this is super simple, but the documentation doesn't seem to cover this (at least not apparently). 回答1: One way is to use tolist() : >>> df['new_column'] = df[['lat', 'long']].values.tolist() >>>

问题 This question already has answers here : Geographic / geospatial distance between 2 lists of lat/lon points (coordinates) (3 answers) Closed 4 years ago . My question is similar to Merging two data frames, both with coordinates based on the closest location. I would like to merge two dataframes in R by latitude and longitude: Dataframe 1 structure(list(lat = c(54L, 55L, 51L, 54L, 53L, 50L, 47L, 51L, 49L, 54L), lon = c(14L, 8L, 15L, 7L, 6L, 5L, 13L, 5L, 13L, 11L ), PPP2000_40 = c(4606, 6575,

问题 Once again a seemingly easy problem, but ... I have this small data frame named “d1" in R: [,1] [,2] [1,] "SHY" "75000" [2,] "IGLIX" “25000" All I want to do is convert the characters in column 2 to numerics. After fiddling with this for an hour all I can figure out that works is: a <- data.frame(d1[,1]) b <- data.frame(as.numeric(d1[,2])) cbind(a, b) which gives me: d1...1. as.numeric.d1...2.. 1 SHY 75000 2 IGLIX 25000 Surely there is an easier way to do this? I tried “apply" unsuccessfully.

问题 Adding on to what's already being said or commented on this post: Cumulative sum until maximum reached, then repeat from zero in the next row I've a similar dataframe which has about 50k+ observations. This dataframe was being read from a csv file and is an outcome of several operations already performed on it. Pasting a sample here: Home Date Time Appliance Run value 679 2 1/21/2017 1:30:00 0 1 0 680 2 1/21/2017 1:45:00 0 1 0 681 2 1/21/2017 2:00:00 0 1 0 682 2 1/21/2017 2:15:00 0 1 0 683 2

问题 I am trying to run Cox proportional hazard model on a data of 4 groups. Here's the data: I am using this code: time_Allo_NHL<- c(28,32,49,84,357,933,1078,1183,1560,2114,2144) censor_Allo_NHL<- c(rep(1,5), rep(0,6)) time_Auto_NHL<- c(42,53,57,63,81,140,176,210,252,476,524,1037) censor_Auto_NHL<- c(rep(1,7), rep(0,1), rep(1,1), rep(0,1), rep(1,1), rep(0,1)) time_Allo_HOD<- c(2,4,72,77,79) censor_Allo_HOD<- c(rep(1,5)) time_Auto_HOD<- c(30,36,41,52,62,108,132,180,307,406,446,484,748,1290,1345)

问题 This question already has answers here : Reshaping data.frame from wide to long format (9 answers) Closed 2 years ago . I have a data frame that I would like to stack in R so that I end up with three columns. Below cis some example data in its current format. > dput(df) structure(list(Day = c("d1", "d2", "d3", "d4", "d5", "d6", "d7", "d8", "d9", "d10"), A1 = c(14L, 24L, 22L, NA, NA, NA, NA, NA, NA, NA), A2 = c(9L, 15L, 34L, 2L, 12L, 34L, 234L, 34L, NA, NA ), A3 = c(3L, 4L, 19L, 76L, 34L, 34L,

问题 This question already has answers here : Reshaping data.frame from wide to long format (9 answers) Closed 2 years ago . I have a data frame that I would like to stack in R so that I end up with three columns. Below cis some example data in its current format. > dput(df) structure(list(Day = c("d1", "d2", "d3", "d4", "d5", "d6", "d7", "d8", "d9", "d10"), A1 = c(14L, 24L, 22L, NA, NA, NA, NA, NA, NA, NA), A2 = c(9L, 15L, 34L, 2L, 12L, 34L, 234L, 34L, NA, NA ), A3 = c(3L, 4L, 19L, 76L, 34L, 34L,

问题 I have a list of several data.frames. Each data.frame has several columns. By using mean(mylist$first_dataframe$a I can get the mean for a in this one data.frame. However I do not know how to calculate over all the data.frames stored in my list or how for specific data.frames. I could use a loop but I was told that apply() and its variations are better I tried using several solutions I found via search but somehow it just doesn't work. I assume I need to use unlist() Could you provide an