lag

问题 I am wondering if there is an easy way to create a lag (or lead) of a time series variable in Julia according to a by group or condition? For example: I have a dataset of the following form julia> df1 = DataFrame(var1=["a","a","a","a","b","b","b","b"], var2=[0,1,2,3,0,1,2,3]) 8×2 DataFrame │ Row │ var1 │ var2 │ │ │ String │ Int64 │ ├─────┼────────┼───────┤ │ 1 │ a │ 0 │ │ 2 │ a │ 1 │ │ 3 │ a │ 2 │ │ 4 │ a │ 3 │ │ 5 │ b │ 0 │ │ 6 │ b │ 1 │ │ 7 │ b │ 2 │ │ 8 │ b │ 3 │ And I want to create a

问题 I am working with ThreeJS on a basic 3d scene that has OrbitControls. Everything works great, except it causes my entire site to lag, as it is looping itself even when the user is not looking at it. I want a function that I can call to start and stop the rendering when certain conditions are met (in this case, the user isn't viewing the canvas). I have a start function that works just fine, but the stop function does not seem to be working, as my site goes unbearably slow after ThreeJS has

问题 I need to know the frequency of order for each user. I mean difference between 2 order time for each user. In SQL I used "Lag Partition by" but I don't know how I can calculate this in click house. I need this data: at first I should sort data with user_id and created_at then I need to have next order time for each user id in row. I can't use neighbor function because it can't do partition by user_id. 回答1: I didn't understand why neighbor cannot be used in your case, but it should works well:

来源： https://stackoverflow.com/questions/33049092/difference-between-rows-in-r-on-dataframe-grouped-by-column

问题 I am having a very hard time leading or lagging an entire dataframe. What I am able to do is shifting individual columns with the following attempts but not the whole thing: require('DataCombine') df_l <- slide(df, Var = var1, slideBy = -1) using colnames(x_ret_mon) as Var does not work, I am told the variable names are not found in the dataframe. This attempt shifts the columns right but not down: df_l<- dplyr::lag(df) This only creates new variables for the lagged variables but then I do

问题 I am having a very hard time leading or lagging an entire dataframe. What I am able to do is shifting individual columns with the following attempts but not the whole thing: require('DataCombine') df_l <- slide(df, Var = var1, slideBy = -1) using colnames(x_ret_mon) as Var does not work, I am told the variable names are not found in the dataframe. This attempt shifts the columns right but not down: df_l<- dplyr::lag(df) This only creates new variables for the lagged variables but then I do

问题 I have two signals which are related to each other and have been captured by two different measurement devices simultaneously. Since the two measurements are not time synchronized there is a small time delay between them which I want to calculate. Additionally, I need to know which signal is the leading one. The following can be assumed: no or only very less noise present speed of the algorithm is not an issue, only accuracy and robustness signals are captured with an high sampling rate (>10

问题 I have two signals which are related to each other and have been captured by two different measurement devices simultaneously. Since the two measurements are not time synchronized there is a small time delay between them which I want to calculate. Additionally, I need to know which signal is the leading one. The following can be assumed: no or only very less noise present speed of the algorithm is not an issue, only accuracy and robustness signals are captured with an high sampling rate (>10

问题 I'm unable to utilize SQLite window functions (e.g. LAG, LEAD). After some investigation it seems that this is due to the fact that SQLite database version is below 3.25.0, after which window functions were made available. Database created using SQLite 3.30.1 version However version 3.24.0 version displayed on this 'test' database When queries which include window functions are tested, such as the ones provided on sqlitetutorial site: the following errors are displayed Could you please advise

问题 I'm unable to utilize SQLite window functions (e.g. LAG, LEAD). After some investigation it seems that this is due to the fact that SQLite database version is below 3.25.0, after which window functions were made available. Database created using SQLite 3.30.1 version However version 3.24.0 version displayed on this 'test' database When queries which include window functions are tested, such as the ones provided on sqlitetutorial site: the following errors are displayed Could you please advise