每当我们打印任何矢量时，R窗口的左侧都会显示索引，即使矢量中有一个值，索引也会存在。例如，如果我们打印一个值等于2的向量，则打印输出将为[1] 2，其中[1]代表索引。如果我们要打印不带索引的向量，则可以使用cat函数，如以下示例所示。
x1<−1:50 x1输出结果
[1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 [26] 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
cat(x1,fill=TRUE)输出结果
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
x2<−rnorm(80) x2输出结果
[1] −0.80521374 0.31958949 −1.48420309 0.81002518 −0.21996595 −1.00172996 [7] 0.22351739 0.88238127 −0.39634599 −0.03713212 −0.98835229 −1.25814376 [13] 0.87085572 −0.85611684 −0.29874494 −1.24726965 0.58367707 0.59283764 [19] 1.12208675 −0.99539174 −1.00296505 0.14744371 1.07498541 −0.06393804 [25] 1.05421836 0.78820041 −1.83124330 −0.39376746 0.78146314 1.73795705 [31] 0.76103401 −0.99425354 −0.68722593 0.41017802 2.17813236 0.55434245 [37] 0.62527078 −0.56166543 0.06025381 0.81553325 0.38276496 −0.54946978 [43] 2.82117758 −0.39764193 1.13038425 −0.13615824 −0.32063000 −0.22354904 [49] −1.70144034 −0.87538953 0.71908202 −0.68515454 0.68152735 −3.61314448 [55] −0.45074050 −1.19185745 −0.38136640 0.44618919 −2.15542430 −0.46384009 [61] 0.75799481 0.93987283 1.23951174 0.30288382 −1.48214127 −1.93995177 [67] −0.58862690 −0.09822009 1.10421757 0.48513715 −0.55996766 0.72119011 [73] 2.24702108 −0.37606973 0.66518716 1.15377041 1.19221007 0.47804031 [79] 0.33829431 −0.63047169
cat(x2,fill=TRUE)输出结果
−0.8052137 0.3195895 −1.484203 0.8100252 −0.219966 −1.00173 0.2235174 0.8823813 −0.396346 −0.03713212 −0.9883523 −1.258144 0.8708557 −0.8561168 −0.2987449 −1.24727 0.5836771 0.5928376 1.122087 −0.9953917 −1.002965 0.1474437 1.074985 −0.06393804 1.054218 0.7882004 −1.831243 −0.3937675 0.7814631 1.737957 0.761034 −0.9942535 −0.6872259 0.410178 2.178132 0.5543425 0.6252708 −0.5616654 0.06025381 0.8155332 0.382765 −0.5494698 2.821178 −0.3976419 1.130384 −0.1361582 −0.32063 −0.223549 −1.70144 −0.8753895 0.719082 −0.6851545 0.6815273 −3.613144 −0.4507405 −1.191857 −0.3813664 0.4461892 −2.155424 −0.4638401 0.7579948 0.9398728 1.239512 0.3028838 −1.482141 −1.939952 −0.5886269 −0.09822009 1.104218 0.4851372 −0.5599677 0.7211901 2.247021 −0.3760697 0.6651872 1.15377 1.19221 0.4780403 0.3382943 −0.6304717
x3<−rpois(150,5) x3输出结果
[1] 1 6 7 7 6 8 5 2 7 2 6 4 5 5 3 6 3 3 7 6 1 8 6 6 6 [26] 2 3 4 4 4 4 5 2 5 8 1 3 3 4 3 1 3 6 6 10 6 2 5 5 2 [51] 7 4 4 9 6 7 2 6 2 5 5 7 4 3 7 6 4 2 6 8 6 7 3 4 8 [76] 2 6 5 4 5 4 5 5 3 5 6 6 8 3 4 4 7 6 4 4 2 5 7 2 10 [101] 3 5 5 6 7 9 2 7 9 5 7 6 0 4 6 7 8 4 5 3 4 3 7 7 5 [126] 13 4 3 9 9 7 6 4 7 8 5 7 4 7 4 9 5 8 4 1 6 6 2 10 7
cat(x3,fill=TRUE)输出结果
1 6 7 7 6 8 5 2 7 2 6 4 5 5 3 6 3 3 7 6 1 8 6 6 6 2 3 4 4 4 4 5 2 5 8 1 3 3 4 3 1 3 6 6 10 6 2 5 5 2 7 4 4 9 6 7 2 6 2 5 5 7 4 3 7 6 4 2 6 8 6 7 3 4 8 2 6 5 4 5 4 5 5 3 5 6 6 8 3 4 4 7 6 4 4 2 5 7 2 10 3 5 5 6 7 9 2 7 9 5 7 6 0 4 6 7 8 4 5 3 4 3 7 7 5 13 4 3 9 9 7 6 4 7 8 5 7 4 7 4 9 5 8 4 1 6 6 2 10 7
x4<−runif(80,2,5) x4输出结果
[1] 4.435970 2.624657 2.451233 4.442715 2.190130 2.226768 3.177817 2.178521 [9] 2.234834 2.228027 4.381513 2.052545 2.744667 3.162011 4.731392 4.378479 [17] 4.474160 3.416653 4.903176 3.525459 4.711460 4.337899 3.336221 4.640738 [25] 3.075943 4.630204 4.372429 4.393392 4.678343 2.356057 3.652575 4.311324 [33] 2.333218 3.325070 3.993173 4.402070 3.938035 2.853330 3.731457 2.789883 [41] 4.016687 3.593640 4.553039 2.479682 2.235848 3.975596 4.436557 4.888424 [49] 3.426769 3.536130 3.465132 4.423580 4.008968 2.218030 4.907232 3.751205 [57] 2.782190 4.860979 3.680459 3.953126 4.426685 4.086084 4.101165 4.857805 [65] 2.475631 4.177959 4.936971 3.693090 4.383131 4.638622 4.576787 2.672324 [73] 4.619832 3.576587 4.285013 2.985745 2.228742 3.732050 2.636020 4.450006
cat(x4,fill=TRUE)输出结果
4.43597 2.624657 2.451233 4.442715 2.19013 2.226768 3.177817 2.178521 2.234834 2.228027 4.381513 2.052545 2.744667 3.162011 4.731392 4.378479 4.47416 3.416653 4.903176 3.525459 4.71146 4.337899 3.336221 4.640738 3.075943 4.630204 4.372429 4.393392 4.678343 2.356057 3.652575 4.311324 2.333218 3.32507 3.993173 4.40207 3.938035 2.85333 3.731457 2.789883 4.016687 3.59364 4.553039 2.479682 2.235848 3.975596 4.436557 4.888424 3.426769 3.53613 3.465132 4.42358 4.008968 2.21803 4.907232 3.751205 2.78219 4.860979 3.680459 3.953126 4.426685 4.086084 4.101165 4.857805 2.475631 4.177959 4.936971 3.69309 4.383131 4.638622 4.576787 2.672324 4.619832 3.576587 4.285013 2.985745 2.228742 3.73205 2.63602 4.450006
x5<−rexp(50,2.35) x5输出结果
[1] 1.016516217 0.721335837 0.338276694 0.400194614 0.582205216 0.007181041 [7] 0.199392134 0.409682007 0.159855571 0.508902457 1.154262683 0.099887098 [13] 0.103252343 0.906729850 0.050266374 0.057188442 0.519506878 0.402857089 [19] 0.218303973 0.047213354 0.201429579 0.469359258 0.378838251 0.107099142 [25] 0.359931404 0.811271829 0.422585112 0.655336554 0.157745503 0.270419961 [31] 0.273113782 0.044406735 0.987502275 1.803740455 0.810761784 0.230156457 [37] 0.011306944 0.107074123 2.575930173 0.120097098 0.069905263 0.004458232 [43] 0.130728411 0.263245955 0.247016598 0.056639419 0.444263721 0.155409799 [49] 0.136015234 0.727748260
cat(x5,fill=TRUE)输出结果
1.016516 0.7213358 0.3382767 0.4001946 0.5822052 0.007181041 0.1993921 0.409682 0.1598556 0.5089025 1.154263 0.0998871 0.1032523 0.9067298 0.05026637 0.05718844 0.5195069 0.4028571 0.218304 0.04721335 0.2014296 0.4693593 0.3788383 0.1070991 0.3599314 0.8112718 0.4225851 0.6553366 0.1577455 0.27042 0.2731138 0.04440673 0.9875023 1.80374 0.8107618 0.2301565 0.01130694 0.1070741 2.57593 0.1200971 0.06990526 0.004458232 0.1307284 0.263246 0.2470166 0.05663942 0.4442637 0.1554098 0.1360152 0.7277483