Import stock prices

stocks <- tq_get(c("TSLA", "AMZN"),
                 get = "stock.prices",
                 from = "2016-01-01",
                 to = "2017-01-01")
stocks
## # A tibble: 504 × 8
##    symbol date        open  high   low close    volume adjusted
##    <chr>  <date>     <dbl> <dbl> <dbl> <dbl>     <dbl>    <dbl>
##  1 TSLA   2016-01-04  15.4  15.4  14.6  14.9 102406500     14.9
##  2 TSLA   2016-01-05  15.1  15.1  14.7  14.9  47802000     14.9
##  3 TSLA   2016-01-06  14.7  14.7  14.4  14.6  56686500     14.6
##  4 TSLA   2016-01-07  14.3  14.6  14.2  14.4  53314500     14.4
##  5 TSLA   2016-01-08  14.5  14.7  14.1  14.1  54421500     14.1
##  6 TSLA   2016-01-11  14.3  14.3  13.5  13.9  61371000     13.9
##  7 TSLA   2016-01-12  14.1  14.2  13.7  14.0  46378500     14.0
##  8 TSLA   2016-01-13  14.1  14.2  13.3  13.4  61896000     13.4
##  9 TSLA   2016-01-14  13.5  14    12.9  13.7  97360500     13.7
## 10 TSLA   2016-01-15  13.3  13.7  13.2  13.7  83679000     13.7
## # … with 494 more rows

Plot stock prices

stocks %>%
    
    ggplot(aes(x = date, y = adjusted, color = symbol)) +
    geom_line()

Apply the dplyr verbs you learned in chapter 5

Filter Rows

stocks %>% filter(adjusted > 24)
## # A tibble: 252 × 8
##    symbol date        open  high   low close    volume adjusted
##    <chr>  <date>     <dbl> <dbl> <dbl> <dbl>     <dbl>    <dbl>
##  1 AMZN   2016-01-04  32.8  32.9  31.4  31.8 186290000     31.8
##  2 AMZN   2016-01-05  32.3  32.3  31.4  31.7 116452000     31.7
##  3 AMZN   2016-01-06  31.1  32.0  31.0  31.6 106584000     31.6
##  4 AMZN   2016-01-07  31.1  31.5  30.3  30.4 141498000     30.4
##  5 AMZN   2016-01-08  31.0  31.2  30.3  30.4 110258000     30.4
##  6 AMZN   2016-01-11  30.6  31.0  29.9  30.9  97832000     30.9
##  7 AMZN   2016-01-12  31.3  31.3  30.6  30.9  94482000     30.9
##  8 AMZN   2016-01-13  31.0  31.0  29.0  29.1 153104000     29.1
##  9 AMZN   2016-01-14  29.0  30.1  28.5  29.6 144760000     29.6
## 10 AMZN   2016-01-15  28.6  29.2  28.3  28.5 155690000     28.5
## # … with 242 more rows

Arrange rows

arrange(stocks, desc(high), desc(low))
## # A tibble: 504 × 8
##    symbol date        open  high   low close   volume adjusted
##    <chr>  <date>     <dbl> <dbl> <dbl> <dbl>    <dbl>    <dbl>
##  1 AMZN   2016-10-06  42.2  42.4  42.0  42.1 53680000     42.1
##  2 AMZN   2016-10-07  42.3  42.3  41.9  42.0 48524000     42.0
##  3 AMZN   2016-10-05  41.9  42.3  41.8  42.2 69382000     42.2
##  4 AMZN   2016-10-10  42.2  42.3  42.0  42.1 36542000     42.1
##  5 AMZN   2016-10-25  42.0  42.2  41.7  41.8 64968000     41.8
##  6 AMZN   2016-10-04  42.0  42.1  41.5  41.7 59006000     41.7
##  7 AMZN   2016-10-11  42.1  42.1  41.4  41.5 71764000     41.5
##  8 AMZN   2016-09-30  41.6  42.0  41.6  41.9 88612000     41.9
##  9 AMZN   2016-10-03  41.8  42.0  41.6  41.8 55388000     41.8
## 10 AMZN   2016-10-24  41.2  41.9  41.1  41.9 81218000     41.9
## # … with 494 more rows

Select columns

select(stocks, date:volume)
## # A tibble: 504 × 6
##    date        open  high   low close    volume
##    <date>     <dbl> <dbl> <dbl> <dbl>     <dbl>
##  1 2016-01-04  15.4  15.4  14.6  14.9 102406500
##  2 2016-01-05  15.1  15.1  14.7  14.9  47802000
##  3 2016-01-06  14.7  14.7  14.4  14.6  56686500
##  4 2016-01-07  14.3  14.6  14.2  14.4  53314500
##  5 2016-01-08  14.5  14.7  14.1  14.1  54421500
##  6 2016-01-11  14.3  14.3  13.5  13.9  61371000
##  7 2016-01-12  14.1  14.2  13.7  14.0  46378500
##  8 2016-01-13  14.1  14.2  13.3  13.4  61896000
##  9 2016-01-14  13.5  14    12.9  13.7  97360500
## 10 2016-01-15  13.3  13.7  13.2  13.7  83679000
## # … with 494 more rows
select(stocks, date, open, close)
## # A tibble: 504 × 3
##    date        open close
##    <date>     <dbl> <dbl>
##  1 2016-01-04  15.4  14.9
##  2 2016-01-05  15.1  14.9
##  3 2016-01-06  14.7  14.6
##  4 2016-01-07  14.3  14.4
##  5 2016-01-08  14.5  14.1
##  6 2016-01-11  14.3  13.9
##  7 2016-01-12  14.1  14.0
##  8 2016-01-13  14.1  13.4
##  9 2016-01-14  13.5  13.7
## 10 2016-01-15  13.3  13.7
## # … with 494 more rows

Add columns

returns <- mutate(stocks,
       returns = open - close) %>% 
    
    select(returns)

Summarise with groups

stocks %>% 
    
    #Group by stock
    group_by(symbol) %>%
    
    #Calculate average returns
    summarise(avg.return = mean(returns, na.rm = TRUE)) %>%
    
    #Sort it 
    arrange(symbol)
## Warning in mean.default(returns, na.rm = TRUE): argument is not numeric or
## logical: returning NA

## Warning in mean.default(returns, na.rm = TRUE): argument is not numeric or
## logical: returning NA
## # A tibble: 2 × 2
##   symbol avg.return
##   <chr>       <dbl>
## 1 AMZN           NA
## 2 TSLA           NA