[R] Re sults sometimes in seconds with difftime unit=mins
Hello, I'm trying to calculate an integration and x-axis is a time (format : %Y-%m-%d %H:%M:%S). I use diff(date, units=mins) in a loop for but sometimes the results stay in seconds (95% is ok). Examples for 2 sets of data are given below (first result stays in seconds whereas the second in minutes as expected). Have you already seen this behaviour ? Any idea to solve this problem ? Thanks in advance. Have a good week-end, Ptit Bleu. strptime(datajour$Date, format=%Y-%m-%d %H:%M:%S) [1] 2009-03-26 11:21:31 2009-03-26 11:22:17 2009-03-26 11:27:18 2009-03-26 11:36:59 2009-03-26 11:41:59 2009-03-26 11:46:59 [7] 2009-03-26 11:51:59 2009-03-26 11:57:00 2009-03-26 12:02:00 2009-03-26 12:07:00 2009-03-26 12:12:00 2009-03-26 12:17:00 [13] 2009-03-26 12:22:00 2009-03-26 12:27:01 2009-03-26 12:32:01 2009-03-26 12:37:01 2009-03-26 12:42:01 2009-03-26 12:47:01 [19] 2009-03-26 12:52:01 2009-03-26 12:57:01 2009-03-26 13:02:02 2009-03-26 13:07:02 2009-03-26 13:12:03 2009-03-26 13:17:03 [25] 2009-03-26 13:22:03 2009-03-26 13:27:03 2009-03-26 13:32:03 2009-03-26 13:37:03 2009-03-26 13:42:03 2009-03-26 13:47:03 [31] 2009-03-26 13:52:03 2009-03-26 13:57:04 2009-03-26 14:01:02 2009-03-26 14:06:05 2009-03-26 14:11:05 2009-03-26 14:16:06 [37] 2009-03-26 14:21:06 2009-03-26 14:26:08 2009-03-26 14:31:09 2009-03-26 14:36:10 2009-03-26 14:41:10 2009-03-26 14:46:15 [43] 2009-03-26 14:51:15 2009-03-26 14:56:15 2009-03-26 15:01:15 2009-03-26 15:06:17 2009-03-26 15:11:17 2009-03-26 15:16:19 [49] 2009-03-26 15:21:19 2009-03-26 15:26:19 2009-03-26 15:31:22 2009-03-26 15:36:23 2009-03-26 15:41:24 2009-03-26 15:46:24 [55] 2009-03-26 15:51:25 2009-03-26 15:56:25 2009-03-26 16:01:25 2009-03-26 16:06:26 2009-03-26 16:11:26 2009-03-26 16:16:26 [61] 2009-03-26 16:21:27 2009-03-26 16:26:27 2009-03-26 16:31:28 2009-03-26 16:36:28 2009-03-26 16:41:29 2009-03-26 16:46:30 [67] 2009-03-26 16:51:31 2009-03-26 16:56:31 2009-03-26 17:01:32 2009-03-26 17:06:32 2009-03-26 17:11:33 2009-03-26 17:16:33 [73] 2009-03-26 17:21:33 2009-03-26 17:26:35 2009-03-26 17:31:36 2009-03-26 17:36:36 2009-03-26 17:41:36 2009-03-26 17:46:36 [79] 2009-03-26 17:51:39 2009-03-26 17:56:40 2009-03-26 18:01:40 2009-03-26 18:06:40 2009-03-26 18:11:40 2009-03-26 18:16:40 [85] 2009-03-26 18:21:41 2009-03-26 18:26:41 2009-03-26 18:31:41 2009-03-26 18:36:41 2009-03-26 18:41:41 2009-03-26 18:46:41 [91] 2009-03-26 18:51:42 2009-03-26 18:56:42 2009-03-26 19:06:42 as.numeric(diff(strptime(datajour$Date, format=%Y-%m-%d %H:%M:%S), units=mins)) [1] 46 301 581 300 300 300 301 300 300 300 300 300 301 300 300 300 300 300 300 301 300 301 300 300 300 300 300 300 300 300 301 238 303 300 301 300 302 301 [39] 301 300 305 300 300 300 302 300 302 300 300 303 301 301 300 301 300 300 301 300 300 301 300 301 300 301 301 301 300 301 300 301 300 300 302 301 300 300 [77] 300 303 301 300 300 300 300 301 300 300 300 300 300 301 300 600 strptime(datajour$Date, format=%Y-%m-%d %H:%M:%S) [1] 2009-03-26 11:22:24 2009-03-26 11:27:25 2009-03-26 11:37:04 2009-03-26 11:42:04 2009-03-26 11:47:04 2009-03-26 11:52:04 [7] 2009-03-26 11:57:04 2009-03-26 12:02:05 2009-03-26 12:07:06 2009-03-26 12:12:06 2009-03-26 12:17:06 2009-03-26 12:22:06 [13] 2009-03-26 12:27:07 2009-03-26 12:32:07 2009-03-26 12:37:07 2009-03-26 12:42:07 2009-03-26 12:47:07 2009-03-26 12:52:08 [19] 2009-03-26 12:57:08 2009-03-26 13:02:08 2009-03-26 13:07:09 2009-03-26 13:12:09 2009-03-26 13:17:09 2009-03-26 13:22:09 [25] 2009-03-26 13:27:09 2009-03-26 13:32:09 2009-03-26 13:37:09 2009-03-26 13:42:09 2009-03-26 13:47:09 2009-03-26 13:52:09 [31] 2009-03-26 13:57:10 2009-03-26 14:01:08 2009-03-26 14:06:11 2009-03-26 14:11:11 2009-03-26 14:16:12 2009-03-26 14:21:12 [37] 2009-03-26 14:26:15 2009-03-26 14:31:18 2009-03-26 14:36:18 2009-03-26 14:41:19 2009-03-26 14:46:22 2009-03-26 14:51:22 [43] 2009-03-26 14:56:23 2009-03-26 15:01:24 2009-03-26 15:06:24 2009-03-26 15:11:24 2009-03-26 15:16:24 2009-03-26 15:21:24 [49] 2009-03-26 15:26:24 2009-03-26 15:31:28 2009-03-26 15:36:29 2009-03-26 15:41:29 2009-03-26 15:46:30 2009-03-26 15:51:33 [55] 2009-03-26 15:56:33 2009-03-26 16:01:33 2009-03-26 16:06:33 2009-03-26 16:11:34 2009-03-26 16:16:34 2009-03-26 16:21:35 [61] 2009-03-26 16:26:35 2009-03-26 16:31:35 2009-03-26 16:36:35 2009-03-26 16:41:35 2009-03-26 16:46:36 2009-03-26 16:51:37 [67] 2009-03-26 16:56:37 2009-03-26 17:01:37 2009-03-26 17:06:38 2009-03-26 17:11:38 2009-03-26 17:16:38 2009-03-26 17:21:38 [73] 2009-03-26 17:26:40 2009-03-26 17:31:43 2009-03-26 17:36:43 2009-03-26 17:41:43 2009-03-26 17:46:44 2009-03-26 17:51:45 [79] 2009-03-26 17:56:46 2009-03-26 18:01:46 2009-03-26 18:06:46 2009-03-26 18:11:47 2009-03-26 18:16:47 2009-03-26 18:21:48 [85] 2009-03-26 18:26:48 2009-03-26 18:31:48 2009-03-26 18:36:48 2009-03-26 18:41:48 2009-03-26 18:46:48 2009-03-26 18:51:48 [91] 2009-03-26
Re: [R] Re sults sometimes in seconds with difftime unit=mins
I think the problem is is that 'diff' does not have a 'units' parameter; 'difftime' does. Here is a way of doing it: x [1] 2009-03-27 13:00:00 EDT 2009-03-27 13:00:35 EDT 2009-03-27 13:01:10 EDT 2009-03-27 13:01:45 EDT 2009-03-27 13:02:20 EDT 2009-03-27 13:02:55 EDT 2009-03-27 13:03:30 EDT [8] 2009-03-27 13:04:05 EDT 2009-03-27 13:04:40 EDT 2009-03-27 13:05:15 EDT difftime(tail(x, -1), head(x, -1), units='mins') Time differences in mins [1] 0.583 0.583 0.583 0.583 0.583 0.583 0.583 0.583 0.583 attr(,tzone) [1] diff(x, units='mins') # 'units' ignored Time differences in secs [1] 35 35 35 35 35 35 35 35 35 attr(,tzone) [1] On Fri, Mar 27, 2009 at 11:04 AM, Ptit_Bleu ptit_b...@yahoo.fr wrote: Hello, I'm trying to calculate an integration and x-axis is a time (format : %Y-%m-%d %H:%M:%S). I use diff(date, units=mins) in a loop for but sometimes the results stay in seconds (95% is ok). Examples for 2 sets of data are given below (first result stays in seconds whereas the second in minutes as expected). Have you already seen this behaviour ? Any idea to solve this problem ? Thanks in advance. Have a good week-end, Ptit Bleu. strptime(datajour$Date, format=%Y-%m-%d %H:%M:%S) [1] 2009-03-26 11:21:31 2009-03-26 11:22:17 2009-03-26 11:27:18 2009-03-26 11:36:59 2009-03-26 11:41:59 2009-03-26 11:46:59 [7] 2009-03-26 11:51:59 2009-03-26 11:57:00 2009-03-26 12:02:00 2009-03-26 12:07:00 2009-03-26 12:12:00 2009-03-26 12:17:00 [13] 2009-03-26 12:22:00 2009-03-26 12:27:01 2009-03-26 12:32:01 2009-03-26 12:37:01 2009-03-26 12:42:01 2009-03-26 12:47:01 [19] 2009-03-26 12:52:01 2009-03-26 12:57:01 2009-03-26 13:02:02 2009-03-26 13:07:02 2009-03-26 13:12:03 2009-03-26 13:17:03 [25] 2009-03-26 13:22:03 2009-03-26 13:27:03 2009-03-26 13:32:03 2009-03-26 13:37:03 2009-03-26 13:42:03 2009-03-26 13:47:03 [31] 2009-03-26 13:52:03 2009-03-26 13:57:04 2009-03-26 14:01:02 2009-03-26 14:06:05 2009-03-26 14:11:05 2009-03-26 14:16:06 [37] 2009-03-26 14:21:06 2009-03-26 14:26:08 2009-03-26 14:31:09 2009-03-26 14:36:10 2009-03-26 14:41:10 2009-03-26 14:46:15 [43] 2009-03-26 14:51:15 2009-03-26 14:56:15 2009-03-26 15:01:15 2009-03-26 15:06:17 2009-03-26 15:11:17 2009-03-26 15:16:19 [49] 2009-03-26 15:21:19 2009-03-26 15:26:19 2009-03-26 15:31:22 2009-03-26 15:36:23 2009-03-26 15:41:24 2009-03-26 15:46:24 [55] 2009-03-26 15:51:25 2009-03-26 15:56:25 2009-03-26 16:01:25 2009-03-26 16:06:26 2009-03-26 16:11:26 2009-03-26 16:16:26 [61] 2009-03-26 16:21:27 2009-03-26 16:26:27 2009-03-26 16:31:28 2009-03-26 16:36:28 2009-03-26 16:41:29 2009-03-26 16:46:30 [67] 2009-03-26 16:51:31 2009-03-26 16:56:31 2009-03-26 17:01:32 2009-03-26 17:06:32 2009-03-26 17:11:33 2009-03-26 17:16:33 [73] 2009-03-26 17:21:33 2009-03-26 17:26:35 2009-03-26 17:31:36 2009-03-26 17:36:36 2009-03-26 17:41:36 2009-03-26 17:46:36 [79] 2009-03-26 17:51:39 2009-03-26 17:56:40 2009-03-26 18:01:40 2009-03-26 18:06:40 2009-03-26 18:11:40 2009-03-26 18:16:40 [85] 2009-03-26 18:21:41 2009-03-26 18:26:41 2009-03-26 18:31:41 2009-03-26 18:36:41 2009-03-26 18:41:41 2009-03-26 18:46:41 [91] 2009-03-26 18:51:42 2009-03-26 18:56:42 2009-03-26 19:06:42 as.numeric(diff(strptime(datajour$Date, format=%Y-%m-%d %H:%M:%S), units=mins)) [1] 46 301 581 300 300 300 301 300 300 300 300 300 301 300 300 300 300 300 300 301 300 301 300 300 300 300 300 300 300 300 301 238 303 300 301 300 302 301 [39] 301 300 305 300 300 300 302 300 302 300 300 303 301 301 300 301 300 300 301 300 300 301 300 301 300 301 301 301 300 301 300 301 300 300 302 301 300 300 [77] 300 303 301 300 300 300 300 301 300 300 300 300 300 301 300 600 strptime(datajour$Date, format=%Y-%m-%d %H:%M:%S) [1] 2009-03-26 11:22:24 2009-03-26 11:27:25 2009-03-26 11:37:04 2009-03-26 11:42:04 2009-03-26 11:47:04 2009-03-26 11:52:04 [7] 2009-03-26 11:57:04 2009-03-26 12:02:05 2009-03-26 12:07:06 2009-03-26 12:12:06 2009-03-26 12:17:06 2009-03-26 12:22:06 [13] 2009-03-26 12:27:07 2009-03-26 12:32:07 2009-03-26 12:37:07 2009-03-26 12:42:07 2009-03-26 12:47:07 2009-03-26 12:52:08 [19] 2009-03-26 12:57:08 2009-03-26 13:02:08 2009-03-26 13:07:09 2009-03-26 13:12:09 2009-03-26 13:17:09 2009-03-26 13:22:09 [25] 2009-03-26 13:27:09 2009-03-26 13:32:09 2009-03-26 13:37:09 2009-03-26 13:42:09 2009-03-26 13:47:09 2009-03-26 13:52:09 [31] 2009-03-26 13:57:10 2009-03-26 14:01:08 2009-03-26 14:06:11 2009-03-26 14:11:11 2009-03-26 14:16:12 2009-03-26 14:21:12 [37] 2009-03-26 14:26:15 2009-03-26 14:31:18 2009-03-26 14:36:18 2009-03-26 14:41:19 2009-03-26 14:46:22 2009-03-26 14:51:22 [43] 2009-03-26 14:56:23 2009-03-26 15:01:24 2009-03-26 15:06:24 2009-03-26 15:11:24 2009-03-26 15:16:24 2009-03-26 15:21:24 [49] 2009-03-26 15:26:24 2009-03-26 15:31:28 2009-03-26 15:36:29 2009-03-26
