title: How to export tibble to .csv
body: <p>I did a rfm analysis using package "rfm". The results are in tibble and I can't seem to figure out how to export it to .csv. I tried argument below but it exported a blank file. </p>
  
  <pre><code>&gt; dim(bmdata4RFM)
  [1] 1182580       3
  &gt; str(bmdata4RFM)
  'data.frame':   1182580 obs. of  3 variables:
   $ customer_ID: num  0 0 0 0 0 0 0 0 0 0 ...
   $ sales_date : Factor w/ 366 levels "1/1/2018 0:00:00",..: 267 275 286 297 300 301 302 303 304 305 ...
   $ sales      : num  101541 110543 60932 75472 43588 ...
  &gt; head(bmdata4RFM,5)
    customer_ID        sales_date     sales
  1           0 6/30/2017 0:00:00 101540.70
  2           0  7/1/2017 0:00:00 110543.35
  3           0  7/2/2017 0:00:00  60932.20
  4           0  7/3/2017 0:00:00  75471.93
  5           0  7/4/2017 0:00:00  43587.70
  &gt; library(rfm)
  &gt; # convert date from factor to date format
  &gt; bmdata4RFM[,2] &lt;- as.Date(as.character(bmdata4RFM[,2]), format = "%m/%d/%Y") 
  &gt; rfm_result_v2
  # A tibble: 535,868 x 9
     customer_id date_most_recent recency_days transaction_count    amount recency_score frequency_score monetary_score rfm_score
           &lt;dbl&gt; &lt;date&gt;                  &lt;dbl&gt;             &lt;dbl&gt;     &lt;dbl&gt;         &lt;int&gt;           &lt;int&gt;          &lt;int&gt;     &lt;dbl&gt;
   1           0 2018-06-30                 12               366 42462470.             5               5              5       555
   2           1 2018-06-30                 12                20     2264.             5               5              5       555
   3           2 2018-01-12                181                24     1689              3               5              5       355
   4           3 2018-05-04                 69                27     1984.             4               5              5       455
   5           6 2017-12-07                217                12      922.             2               5              5       255
   6           7 2018-01-15                178                19     1680.             3               5              5       355
   7           9 2018-01-05                188                19     2106              2               5              5       255
   8          20 2018-04-11                 92                 4      414.             4               5              5       455
   9          26 2018-02-10                152                 1       72              3               1              2       312
  10          48 2017-12-20                204                 1       90              2               1              3       213
  11          68 2017-09-30                285                 1       37              1               1              1       111
  12          70 2017-12-17                207                 1       18              2               1              1       211
  13         104 2017-08-11                335                 1       90              1               1              3       113
  14         120 2017-07-27                350                 1       19              1               1              1       111
  15         134 2018-01-13                180                 1      275              3               1              4       314
  16         153 2018-06-24                 18                10     1677              5               5              5       555
  17         155 2018-05-28                 45                 1      315              5               1              4       514
  18         171 2018-06-11                 31                 6     3485.             5               5              5       555
  19         172 2018-05-24                 49                 1       93              5               1              3       513
  20         174 2018-06-06                 36                 3      347.             5               4              5       545
  # ... with 535,858 more rows
  &gt; write.csv(rfm_result_v2,"bmdataRFMFunction_output071218v2.csv") 
  </code></pre>