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G. Grothendieck

GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
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Top Answers
318
Extract a substring according to a pattern
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291
Can dplyr package be used for conditional mutating?
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237
Filter for complete cases in data.frame using dplyr (case-wise deletion)
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230
promise already under evaluation: recursive default argument reference or earlier problems?
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227
What does %>% function mean in R?
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223
How to assign from a function which returns more than one value?
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151
dplyr mutate with conditional values
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151
How to divide each row of a matrix by elements of a vector in R
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127
How to subtract months from a date in R?
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125
Collapse / concatenate / aggregate a column to a single comma separated string within each group
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100
dplyr mutate/replace several columns on a subset of rows
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87
What does the R function `poly` really do?
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79
Replace <NA> in a factor column
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78
dplyr: How to use group_by inside a function?
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74
Using R to list all files with a specified extension
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73
Add a horizontal line to plot and legend in ggplot2
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69
Converting year and month ("yyyy-mm" format) to a date?
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65
Plotting time-series with Date labels on x-axis
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64
Replace missing values with column mean
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64
Quit and restart a clean R session from within R?
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62
How can I know if R is running on 64 bits versus 32?
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61
How do I convert a factor into date format?
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57
R: How to extract dates from a time series
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52
What's the fastest way to merge/join data.frames in R?
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51
Replace missing values (NA) with most recent non-NA by group
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49
Fast vectorized merge of list of data.frames by row
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44
State name to abbreviation
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39
Why are Xs added to data frame variable names when using read.csv?
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39
How to do an inverse log transformation in R?
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39
Limiting the number of decimals in a dataframe (R)
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