我有以下df：
> str(merged)
'data.frame': 714 obs. of 6 variables:
$ Date : Date, format: "2013-03-29" "2013-03-29" "2013-03-29" "2013-03-29" ...
$ patch : Factor w/ 7 levels "BVG1","BVG11",..: 1 2 3 4 5 6 7 1 2 3 ...
$ prod : num 2.93 2.77 2.86 2.87 3.01 ...
$ workmix_pct: int 100 10 16 13 17 21 22 100 11 19 ...
$ jobcounts : int 9480 968 1551 1267 1625 1946 2123 7328 810 1374 ...
$ travel : num 30.7 34.3 33.8 29.1 28.1 24.9 34 31.8 32.7 36.4 ...
> head(merged)
Date patch prod workmix_pct jobcounts travel
1 2013-03-29 BVG1 2.932208 100 9480 30.7
2 2013-03-29 BVG11 2.769156 10 968 34.3
3 2013-03-29 BVG12 2.857344 16 1551 33.8
4 2013-03-29 BVG13 2.870111 13 1267 29.1
5 2013-03-29 BVG14 3.011260 17 1625 28.1
6 2013-03-29 BVG15 3.236246 21 1946 24.9
我只是想绘制成对的情节和相关性。
我收到错误：
> ggpairs(data=merged, colour=merged$patch)
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
Error in Math.difftime(235.666666666667, base = 10) :
'log' not defined for "difftime" objects
第二次，我尝试没有约会，我可以画对，但仍然有一些错误：
> ggpairs(data=merged_cpy, colour=merged_cpy$patch)
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
知道它是什么以及如何解决这些问题？