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Rating Stats for

Matt Dowle

Rating
1609.58 (1,416th) 		Reputation
48,330 (2,110th)
Page: 1 2 3 4 5 6 ... 7
Title Δ
checking if a data.table is keyed in a function, R 0.00
More efficient rolling join backwards not forwards? 0.00
"by" in data.table (group by) - what am I missing? +1.65
Find first/last row "recursively" by group +2.44
Greatest n per group reference with intervals in R or SQL +0.86
update within by and drop 0.00
last by group for all columns data.table -0.62
Multiple joins/merges with data.tables 0.00
data.table fread function 0.00
data.table inner/outer join with NA in join column of type double b... +0.37
merging data.tables based on columns names +0.88
cast string to IDateTime +1.40
Fast melted data.table operations +1.74
How to pass a parameter by variable into data.table[J()] 0.00
do.call to build and execute data.table commands 0.00
Passing a `data.table` to c++ functions using `Rcpp` and/or `RcppAr... +0.78
Writings functions (procedures) for data.table objects -1.42
Fastest way to drop rows with missing values? -0.89
Assigning NA to groups of variables using data.table +0.08
Is there a way to "auto-name" expression in J 0.00
descending sort in data.table and speed +1.70
How to avoid vector search in data.table 0.00
Retrieving specific values from subsetting a data.table +1.78
How to group by more than one column in data.table? 0.00
Add column to empty data.table in R 0.00
data.table and stratified means +1.74
suppress output in data.table j function +1.70
merging multiple data.table 0.00
data.table error when used through knitr, gWidgetsWWW -0.01
How to perform aggregate function two times with two different crit... 0.00
Why error from na.omit after running scale in R in data.table? 0.00
How to do efficient vectorized update on multiple columns using dat... 0.00
Create a column which increments based on another column in Python +0.17
data.table "key indices" or "group counter" +2.48
Remove a range in data.table +1.72
strsplit by row and distribute results by column in data.frame +0.32
merge data.table when the number of key columns are different +0.40
Turn vector output into columns in data.table? 0.00
Why is as.Date slow on a character vector? +1.10
Proper data structure for a bi-directional key<->val lookup t... +0.62
Why does X[Y] join of data.tables not allow a full outer join, or a... -0.93
Combine set of conditions in data.table to extract value using bina... 0.00
grouping on string fields in R +1.71
Conditional Sum Depending on Other Data Frame Columns +0.69
Create new column in data.table by group 0.00
Filling in missing (blanks) in a data table, per category - backwar... +0.39
Splitting irregular time series into regular monthly averages - R +0.41
merge a data.table with itself after a reference lookup +0.40
How to get column mean for specific rows only? -2.23
Variably selecting/assigning to fields in a data.table 0.00