Change long variable names in data.frame

Question

I got the data.frame df below that have long variable names.

The first part of each name is the main category (rock, soil, land use) and the second part that is usually composed of several names is the levels (eg for rock, 2 levels are sandstone mudstone basalt chert limestone and sandstone conglomerate coquina tephra ).

> df
# A tibble: 5 x 2
  `rock_sandstone conglomerate coquina tephra` `rock_sandstone mudstone basalt chert limestone`
                                         <dbl>                                            <dbl>
1                                     0.000000                                        18.774037
2                                    41.968310                                        30.276509
3                                    32.804031                                         0.000000
4                                     8.669436                                         3.092062
5                                    32.937377                                        19.894776

I want to shorten the variable names by just using the first letter of each word to be like below. I can do that using for example dplyr::rename . However, I have 97 variables and I want to do the same for 20 data.frames that have different variable names. I wonder if there is a faster way to that.

library(dplyr)
df <- df %>% rename("r_sccat"  = 'rock_sandstone conglomerate coquina tephra',
                    "r_smbcl" =  "rock_sandstone mudstone basalt chert limestone")

> df
# A tibble: 5 x 2
    r_sccat   r_smbcl
      <dbl>     <dbl>
1  0.000000 18.774037
2 41.968310 30.276509
3 32.804031  0.000000
4  8.669436  3.092062
5 32.937377 19.894776

DATA

> dput(df)
structure(list(`rock_sandstone conglomerate coquina tephra` = c(0, 
41.9683095321332, 32.8040311360418, 8.66943642122745, 32.9373770476129
), `rock_sandstone mudstone basalt chert limestone` = c(18.7740373237074, 
30.2765089609693, 0, 3.09206176664796, 19.8947759845006)), row.names = c(NA, 
-5L), class = c("tbl_df", "tbl", "data.frame"), .Names = c("rock_sandstone conglomerate coquina tephra", 
"rock_sandstone mudstone basalt chert limestone"))

Answer 1

A bit ugly, but abbreviate and some regex replacement will get you there:

names(df) <- sub("^(.)", "\\1_", abbreviate(gsub("_", " ", names(df))))
df

## A tibble: 5 × 2
#     r_scct   r_smbcl
#      <dbl>     <dbl>
#1  0.000000 18.774037
#2 41.968310 30.276509
#3 32.804031  0.000000
#4  8.669436  3.092062
#5 32.937377 19.894776

Answer 2

I am not familiar with abbreviate, but the same can be achieved directly with a few regexp substitutions:

names( df ) <- gsub( ' ', "", gsub( "([a-z])([a-z]+)", "\\1", names( df ) ) )

using magrittr allows for a cleaner syntax:

require( magrittr )
names( df ) %<>%
    gsub( "([a-z])([a-z]+)", "\\1", . ) %>%
    gsub( " ", "", . )