merge

问题 I am a beginner in programming in R. I am at the moment trying to retrieve some site names from a dataframe containing the X and Y coordinates and site names and copy them into a different dataframe with specific points. FD <- matrix(data =c(rep(1, 500), rep(0, 500), rnorm(1000, mean = 550000, sd=4000), rnorm(1000, mean = 6350000, sd=20000), rep(NA, 1000)), ncol = 4, nrow = 1000, byrow = FALSE) colnames(FD) <- c('Survival', 'X', 'Y', 'Site') FD <- as.data.frame(FD) shpxt <- matrix(c(526654.7

问题 In SQL, you can join two tables without a key so that all records of both tables merge with each other. If pandas.concat() or pandas.merge() or some other pandas syntax supported this, it could help me with one step of a problem I am trying to solve. I found an outer join option on the help documentation, but I could not find an exact syntax to do what I wanted (join all records without a key). To explain this a little better: import pandas as pd lunchmenupairs2 = [["pizza", "italian"],[

问题 In SQL, you can join two tables without a key so that all records of both tables merge with each other. If pandas.concat() or pandas.merge() or some other pandas syntax supported this, it could help me with one step of a problem I am trying to solve. I found an outer join option on the help documentation, but I could not find an exact syntax to do what I wanted (join all records without a key). To explain this a little better: import pandas as pd lunchmenupairs2 = [["pizza", "italian"],[

问题 I have a column with na values that I want to fill according to values from another data frame according to a key. I was wondering if there is any simple way to do so. Example: I have a data frame of objects and their colors like this: object color 0 chair black 1 ball yellow 2 door brown 3 ball **NaN** 4 chair white 5 chair **NaN** 6 ball grey I want to fill na values in the color column with default color from the following data frame: object default_color 0 chair brown 1 ball blue 2 door

问题 I have a column with na values that I want to fill according to values from another data frame according to a key. I was wondering if there is any simple way to do so. Example: I have a data frame of objects and their colors like this: object color 0 chair black 1 ball yellow 2 door brown 3 ball **NaN** 4 chair white 5 chair **NaN** 6 ball grey I want to fill na values in the color column with default color from the following data frame: object default_color 0 chair brown 1 ball blue 2 door

问题 I must be missing something very simple here. I never had a problem merging branches into master on earlier versions of Xcode, but I don't have the option on any projects while using Xcode 11. How should I merge into master? Thanks. 回答1: This is a frustrating Xcode 11 issue. As a workaround you can checkout master first and then merge the required branch into it. 来源： https://stackoverflow.com/questions/58606559/merging-branch-into-master-in-xcode-11

问题 The highlights in the image below shows the logic I want to implement. I realize the syntax is incorrect. Is there a way to conditionally update a record in a MERGE statement only if it the value of one of its columns in the target table is NULL, and the corresponding value in the source table is not null? How would you suggest re-writing this? MERGE dbo.input_311 AS [t] USING dbo.input_311_staging AS [s] ON ([t].[unique key] = [s].[unique key]) WHEN NOT MATCHED BY TARGET THEN INSERT(t.

问题 I have the column like the following. Each column has two pairs each with suffix "a" and "b" - for example col1a, col1b, colNa, colNb and so on till end of the file (> 50000). mydataf <- data.frame (Ind = 1:5, col1a = sample (c(1:3), 5, replace = T), col1b = sample (c(1:3), 5, replace = T), colNa = sample (c(1:3), 5, replace = T), colNb = sample (c(1:3),5, replace = T), K_a = sample (c("A", "B"),5, replace = T), K_b = sample (c("A", "B"),5, replace = T)) mydataf Ind col1a col1b colNa colNb K

问题 I have the column like the following. Each column has two pairs each with suffix "a" and "b" - for example col1a, col1b, colNa, colNb and so on till end of the file (> 50000). mydataf <- data.frame (Ind = 1:5, col1a = sample (c(1:3), 5, replace = T), col1b = sample (c(1:3), 5, replace = T), colNa = sample (c(1:3), 5, replace = T), colNb = sample (c(1:3),5, replace = T), K_a = sample (c("A", "B"),5, replace = T), K_b = sample (c("A", "B"),5, replace = T)) mydataf Ind col1a col1b colNa colNb K

问题 I have a list of many data.frames that I want to merge. The issue here is that each data.frame differs in terms of the number of rows and columns, but they all share the key variables (which I've called "var1" and "var2" in the code below). If the data.frames were identical in terms of columns, I could merely rbind , for which plyr's rbind.fill would do the job, but that's not the case with these data. Because the merge command only works on 2 data.frames, I turned to the Internet for ideas.