Update Data-structures.rmd

That's for matching the listing sequences from lines 232 to 238.
Fix confusion by deleting early object
Merge branch 'master' of github.com:hadley/adv-r
Merge pull request #628 from yuchouchen/patch-1

Update Data-structures.rmd
typo "first time its run" -> "first time it's run"
Merge pull request #630 from daattali/patch-1

typo "first time its run" -> "first time it's run"
Update Data-structures.rmd

Small clarification. When I read the bullet point, I thought it meant creating a data.frame with "the same" (equal) number of rows and columns, which on reflection couldn't be what you meant.
Merge pull request #632 from mbrmbr/patch-1

Update Data-structures.rmd
Update toc
Improve layout on small widths
Note about class
Ooops, forgot about floating