prg3

implement an R function to generate a line graph depecting the trend of time-series dataset .with separate lines for each group ,utilizing ggplot2’s group aesthetic.

step1:load necessary libraries

library(ggplot2)
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

library(tidyr)

step2:load the built-in airpassengers dataset

as.numeric(AirPassengers)

  [1] 112 118 132 129 121 135 148 148 136 119 104 118 115 126 141 135 125 149
 [19] 170 170 158 133 114 140 145 150 178 163 172 178 199 199 184 162 146 166
 [37] 171 180 193 181 183 218 230 242 209 191 172 194 196 196 236 235 229 243
 [55] 264 272 237 211 180 201 204 188 235 227 234 264 302 293 259 229 203 229
 [73] 242 233 267 269 270 315 364 347 312 274 237 278 284 277 317 313 318 374
 [91] 413 405 355 306 271 306 315 301 356 348 355 422 465 467 404 347 305 336
[109] 340 318 362 348 363 435 491 505 404 359 310 337 360 342 406 396 420 472
[127] 548 559 463 407 362 405 417 391 419 461 472 535 622 606 508 461 390 432

as.numeric(time(AirPassengers))

  [1] 1949.000 1949.083 1949.167 1949.250 1949.333 1949.417 1949.500 1949.583
  [9] 1949.667 1949.750 1949.833 1949.917 1950.000 1950.083 1950.167 1950.250
 [17] 1950.333 1950.417 1950.500 1950.583 1950.667 1950.750 1950.833 1950.917
 [25] 1951.000 1951.083 1951.167 1951.250 1951.333 1951.417 1951.500 1951.583
 [33] 1951.667 1951.750 1951.833 1951.917 1952.000 1952.083 1952.167 1952.250
 [41] 1952.333 1952.417 1952.500 1952.583 1952.667 1952.750 1952.833 1952.917
 [49] 1953.000 1953.083 1953.167 1953.250 1953.333 1953.417 1953.500 1953.583
 [57] 1953.667 1953.750 1953.833 1953.917 1954.000 1954.083 1954.167 1954.250
 [65] 1954.333 1954.417 1954.500 1954.583 1954.667 1954.750 1954.833 1954.917
 [73] 1955.000 1955.083 1955.167 1955.250 1955.333 1955.417 1955.500 1955.583
 [81] 1955.667 1955.750 1955.833 1955.917 1956.000 1956.083 1956.167 1956.250
 [89] 1956.333 1956.417 1956.500 1956.583 1956.667 1956.750 1956.833 1956.917
 [97] 1957.000 1957.083 1957.167 1957.250 1957.333 1957.417 1957.500 1957.583
[105] 1957.667 1957.750 1957.833 1957.917 1958.000 1958.083 1958.167 1958.250
[113] 1958.333 1958.417 1958.500 1958.583 1958.667 1958.750 1958.833 1958.917
[121] 1959.000 1959.083 1959.167 1959.250 1959.333 1959.417 1959.500 1959.583
[129] 1959.667 1959.750 1959.833 1959.917 1960.000 1960.083 1960.167 1960.250
[137] 1960.333 1960.417 1960.500 1960.583 1960.667 1960.750 1960.833 1960.917

class(AirPassengers)

[1] "ts"

data<-data.frame(
  Date =seq(as.Date("1949-01-01"),by="month",length.out=length(AirPassengers)),Passengers=as.numeric(AirPassengers),
  Year=as.factor(format(seq(as.Date("1949-01-01"),by="month",length.out =length(AirPassengers)),"%Y")))
head(data,n=20)

         Date Passengers Year
1  1949-01-01        112 1949
2  1949-02-01        118 1949
3  1949-03-01        132 1949
4  1949-04-01        129 1949
5  1949-05-01        121 1949
6  1949-06-01        135 1949
7  1949-07-01        148 1949
8  1949-08-01        148 1949
9  1949-09-01        136 1949
10 1949-10-01        119 1949
11 1949-11-01        104 1949
12 1949-12-01        118 1949
13 1950-01-01        115 1950
14 1950-02-01        126 1950
15 1950-03-01        141 1950
16 1950-04-01        135 1950
17 1950-05-01        125 1950
18 1950-06-01        149 1950
19 1950-07-01        170 1950
20 1950-08-01        170 1950

plot_time_series <- function(data,x_col,y_col,group_col,title="Air passenger Trends"){
  ggplot(data,aes_string(x=x_col,y=y_col,color=group_col,group=group_col))+
    geom_line(size=1.2)+
    geom_point(size =2)+
    labs(title =title,
         x="year",
         y=" Number of Passengers ",
         color="year")+
    theme_minimal()+
    theme(legend.position="top")
}
plot_time_series(data,"Date","Passengers","Year","trend of airline passengers over time")

Warning: `aes_string()` was deprecated in ggplot2 3.0.0.
ℹ Please use tidy evaluation idioms with `aes()`.
ℹ See also `vignette("ggplot2-in-packages")` for more information.

Warning: Using `size` aesthetic for lines was deprecated in ggplot2 3.4.0.
ℹ Please use `linewidth` instead.