mtcars
##                      mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## Mazda RX4           21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## Mazda RX4 Wag       21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## Datsun 710          22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## Hornet 4 Drive      21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## Hornet Sportabout   18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## Valiant             18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## Duster 360          14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## Merc 240D           24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## Merc 230            22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## Merc 280            19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## Merc 280C           17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## Merc 450SE          16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## Merc 450SL          17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## Merc 450SLC         15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## Cadillac Fleetwood  10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
## Chrysler Imperial   14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## Fiat 128            32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
## Honda Civic         30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## Toyota Corolla      33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
## Toyota Corona       21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## Dodge Challenger    15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## AMC Javelin         15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## Camaro Z28          13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## Pontiac Firebird    19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## Fiat X1-9           27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
## Porsche 914-2       26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
## Lotus Europa        30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
## Ford Pantera L      15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## Ferrari Dino        19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## Maserati Bora       15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## Volvo 142E          21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2
aggregate(mtcars$mpg, list(mtcars$am), mean)
##   Group.1        x
## 1       0 17.14737
## 2       1 24.39231
library(readxl)
DataDan <- read_excel("D:/NURSING/2021/Dan/DataDan.xlsx")
## New names:
## * `` -> ...25
## * `` -> ...26
## * `` -> ...27
## * `` -> ...28
DataDan
## # A tibble: 100 x 28
##    Timestamp           `I have read, understood ~` `Name (Optiona~`   Age Gender
##    <dttm>              <chr>                       <lgl>            <dbl> <chr> 
##  1 2021-05-12 17:41:46 Agree                       NA                  18 Female
##  2 2021-05-18 07:57:59 Agree                       NA                  17 Female
##  3 2021-05-18 08:19:13 Agree                       NA                  18 Female
##  4 2021-05-18 08:22:07 Agree                       NA                  16 Female
##  5 2021-05-18 08:37:43 Agree                       NA                  17 Female
##  6 2021-05-18 08:48:36 Agree                       NA                  18 Female
##  7 2021-05-18 08:54:00 Agree                       NA                  19 Female
##  8 2021-05-18 08:56:50 Agree                       NA                  17 Female
##  9 2021-05-18 08:57:40 Agree                       NA                  17 Female
## 10 2021-05-18 08:58:19 Agree                       NA                  18 Female
## # ... with 90 more rows, and 23 more variables: `Social support` <chr>,
## #   `Living condition1` <chr>, `Family income per month` <chr>,
## #   `1. Feeling nervous, anxious, or on edge` <dbl>,
## #   `2. Not being able to stop or control worrying` <dbl>,
## #   `3. Worrying too much about different things` <dbl>,
## #   `4. Trouble relaxing` <dbl>,
## #   `5. Being so restless that it is hard to sit still` <dbl>, ...
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
mtcars%>%
  group_by(am)%>%
  summarize(count = n(), meanmpg = mean(mpg))
## # A tibble: 2 x 3
##      am count meanmpg
##   <dbl> <int>   <dbl>
## 1     0    19    17.1
## 2     1    13    24.4
library(dplyr)
mtcars%>%
  group_by(am, cyl)%>%
  summarize(count = n(), meanmpg = mean(mpg))
## `summarise()` has grouped output by 'am'. You can override using the `.groups`
## argument.
## # A tibble: 6 x 4
## # Groups:   am [2]
##      am   cyl count meanmpg
##   <dbl> <dbl> <int>   <dbl>
## 1     0     4     3    22.9
## 2     0     6     4    19.1
## 3     0     8    12    15.0
## 4     1     4     8    28.1
## 5     1     6     3    20.6
## 6     1     8     2    15.4
library(dplyr)
mtcars%>%
  group_by(am, cyl, gear)%>%
  summarize(count = n(), meanmpg = mean(mpg), staandardd = sd(mpg))
## `summarise()` has grouped output by 'am', 'cyl'. You can override using the
## `.groups` argument.
## # A tibble: 10 x 6
## # Groups:   am, cyl [6]
##       am   cyl  gear count meanmpg staandardd
##    <dbl> <dbl> <dbl> <int>   <dbl>      <dbl>
##  1     0     4     3     1    21.5     NA    
##  2     0     4     4     2    23.6      1.13 
##  3     0     6     3     2    19.8      2.33 
##  4     0     6     4     2    18.5      0.990
##  5     0     8     3    12    15.0      2.77 
##  6     1     4     4     6    28.0      5.12 
##  7     1     4     5     2    28.2      3.11 
##  8     1     6     4     2    21        0    
##  9     1     6     5     1    19.7     NA    
## 10     1     8     5     2    15.4      0.566