r - 如何将数据框中的对象重新定义为数字？

Question

blood_presure <- read.csv("C:/Users/Chance/Downloads/blood_presure.txt", sep="")

blood_presure
   Age Years Weight Height Chin Forearm Pulse Systol   Fraction
1   21     1   71.0   1629  8.0     7.0    88    170 0.04761905
2   22     6   56.5   1569  3.3     5.0    64    120 0.27272727
3   24     5   56.0   1561  3.3     1.3    68    125 0.20833333
4   24     1   61.0   1619  3.7     3.0    52    148 0.04166667
5   25     1   65.0   1566  9.0    12.7    72    140 0.04000000
6   27    19   62.0   1639  3.0     3.3    72    106 0.70370370
7   28     5   53.0   1494  7.3     4.7    64    120 0.17857143
8   28    25   53.0   1568  3.7     4.3    80    108 0.89285714
9   31     6   65.0   1540 10.3     9.0    76    124 0.19354839
10  32    13   57.0   1530  5.7     4.0    60    134 0.40625000
11  33    13   66.5   1622  6.0     5.7    68    116 0.39393939
12  33    10   59.1   1486  6.7     5.3    72    114 0.30303030
13  34    15   64.0   1578  3.3     5.3    88    130 0.44117647
14  35    18   69.5   1645  9.3     5.0    60    118 0.51428571
15  35     2   64.0   1648  3.0     3.7    60    138 0.05714286
16  36    12   56.5   1521  3.3     5.0    72    134 0.33333333
17  36    15   57.0   1547  3.0     3.0    84    120 0.41666667
18  37    16   55.0   1505  4.3     5.0    64    120 0.43243243
19  37    17   57.0   1473  6.0     5.3    72    114 0.45945946
20  38    10   58.0   1538  8.7     6.0    64    124 0.26315789
21  38    18   59.5   1513  5.3     4.0    80    114 0.47368421
22  38    11   61.0   1653  4.0     3.3    76    136 0.28947368
23  38    11   57.0   1566  3.0     3.0    60    126 0.28947368
24  39    21   57.5   1580  4.0     3.0    64    124 0.53846154
25  39    24   74.0   1647  7.3     6.3    64    128 0.61538462
26  39    14   72.0   1620  6.3     7.7    68    134 0.35897436
27  41    25   62.5   1637  6.0     5.3    76    112 0.60975610
28  41    32   68.0   1528 10.0     5.0    60    128 0.78048780
29  41     5   63.4   1647  5.3     4.3    76    134 0.12195122
30  42    12   68.0   1605 11.0     7.0    88    128 0.28571429
31  43    25   69.0   1625  5.0     3.0    72    140 0.58139535
32  43    26   73.0   1615 12.0     4.0    68    138 0.60465116
33  43    10   64.0   1640  5.7     3.0    60    118 0.23255814
34  44    19   65.0   1610  8.0     6.7    74    110 0.43181818
35  44    18   71.0   1572  3.0     4.7    72    142 0.40909091
36  45    10   60.2   1534  3.0     3.0    56    134 0.22222222
37  47     1   55.0   1536  3.0     3.0    64    116 0.02127660
38  50    43   70.0   1630  4.0     6.0    72    132 0.86000000
39  54    40   87.0   1542 11.3    11.7    92    152 0.74074074

cor(Systol,Chin,method="pearson")
#Error in is.data.frame(y) : object 'chin' not found
class(Chin)
#Error: object 'Chin' not found
class("Chin")
#[1] "character"
class(Systol)
#Error: object 'Systol' not found
class("Systol")
#[1] "character"

我正在尝试计算 Systol 和 Chin 之间的相关性，但我遇到了这些错误。我该如何解决？

标签： r