I would like to make a line plot using half-hourly measurements. My problem is that as the number of instances rises, the plot begins to display spike trends rather than a continuous line trend. How can I change this?
Sample code:
ggplot(df, aes(x=Time, y=Price, group=Band)) +
geom_line(aes(color=Band), lwd=1)+
labs(x="Time (hours)", y="Price", title="")+
theme_bw() +
theme(axis.text.x = element_text(angle = 90, hjust = 1)) +
scale_y_continuous(expand = c(0,0))
Sample data for 150 cases above the plot created based on this data;
df<-structure(list(Date = structure(c(1635724800, 1635726600, 1635728400,
1635730200, 1635732000, 1635733800, 1635735600, 1635737400, 1635739200,
1635741000, 1635742800, 1635744600, 1635746400, 1635748200, 1635750000,
1635751800, 1635753600, 1635755400, 1635757200, 1635759000, 1635760800,
1635762600, 1635764400, 1635766200, 1635768000, 1635769800, 1635771600,
1635773400, 1635775200, 1635777000, 1635778800, 1635780600, 1635782400,
1635784200, 1635786000, 1635787800, 1635789600, 1635791400, 1635793200,
1635795000, 1635796800, 1635798600, 1635800400, 1635802200, 1635804000,
1635805800, 1635807600, 1635809400, 1635811200, 1635813000, 1635814800,
1635816600, 1635818400, 1635820200, 1635822000, 1635823800, 1635825600,
1635827400, 1635829200, 1635831000, 1635832800, 1635834600, 1635836400,
1635838200, 1635840000, 1635841800, 1635843600, 1635845400, 1635847200,
1635849000, 1635850800, 1635852600, 1635854400, 1635856200, 1635858000,
1635859800, 1635861600, 1635863400, 1635865200, 1635867000, 1635868800,
1635870600, 1635872400, 1635874200, 1635876000, 1635877800, 1635879600,
1635881400, 1635883200, 1635885000, 1635886800, 1635888600, 1635890400,
1635892200, 1635894000, 1635895800, 1635897600, 1635899400, 1635901200,
1635903000, 1635904800, 1635906600, 1635908400, 1635910200, 1635912000,
1635913800, 1635915600, 1635917400, 1635919200, 1635921000, 1635922800,
1635924600, 1635926400, 1635928200, 1635930000, 1635931800, 1635933600,
1635935400, 1635937200, 1635939000, 1635940800, 1635942600, 1635944400,
1635946200, 1635948000, 1635949800, 1635951600, 1635953400, 1635955200,
1635957000, 1635958800, 1635960600, 1635962400, 1635964200, 1635966000,
1635967800, 1635969600, 1635971400, 1635973200, 1635975000, 1635976800,
1635978600, 1635980400, 1635982200, 1635984000, 1635985800, 1635987600,
1635989400, 1635991200, 1635993000), tzone = "UTC", class = c("POSIXct",
"POSIXt")), Time = structure(c(0, 1800, 3600, 5400, 7200, 9000,
10800, 12600, 14400, 16200, 18000, 19800, 21600, 23400, 25200,
27000, 28800, 30600, 32400, 34200, 36000, 37800, 39600, 41400,
43200, 45000, 46800, 48600, 50400, 52200, 54000, 55800, 57600,
59400, 61200, 63000, 64800, 66600, 68400, 70200, 72000, 73800,
75600, 77400, 79200, 81000, 82800, 84600, 0, 1800, 3600, 5400,
7200, 9000, 10800, 12600, 14400, 16200, 18000, 19800, 21600,
23400, 25200, 27000, 28800, 30600, 32400, 34200, 36000, 37800,
39600, 41400, 43200, 45000, 46800, 48600, 50400, 52200, 54000,
55800, 57600, 59400, 61200, 63000, 64800, 66600, 68400, 70200,
72000, 73800, 75600, 77400, 79200, 81000, 82800, 84600, 0, 1800,
3600, 5400, 7200, 9000, 10800, 12600, 14400, 16200, 18000, 19800,
21600, 23400, 25200, 27000, 28800, 30600, 32400, 34200, 36000,
37800, 39600, 41400, 43200, 45000, 46800, 48600, 50400, 52200,
54000, 55800, 57600, 59400, 61200, 63000, 64800, 66600, 68400,
70200, 72000, 73800, 75600, 77400, 79200, 81000, 82800, 84600,
0, 1800, 3600, 5400, 7200, 9000), class = c("hms", "difftime"
), units = "secs"), Band = c("C", "C", "C", "C", "C", "C", "C",
"C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C",
"C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C",
"C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C",
"C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C",
"C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C",
"C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C",
"C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C",
"C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C",
"C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C",
"C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C",
"C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C"
), Region = c("Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma",
"Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma", "Roma"
), Price = c(3.83, 4.91, 2.97, 1.3, 2.25, 1.3, 1.89, 1.3, 2.05,
2.35, 2.16, 5.2, 9, 9.38, 9.38, 11.84, 13.65, 14.3, 12.42, 11.79,
11.78, 9.38, 11.37, 12.6, 11.33, 12.13, 13.3, 12.4, 14.37, 14.5,
11.6, 14.01, 16.64, 22.46, 24.35, 24.97, 25.21, 23.57, 18.68,
13.84, 16.65, 12.7, 14.22, 9.66, 12.45, 8.41, 12.7, 12.46, 12.56,
12.7, 12.98, 12.89, 13.08, 12.51, 12.42, 12.42, 13.36, 12.7,
15.08, 14.6, 15.08, 16.02, 15.87, 19.75, 18.21, 18.78, 18.48,
17.74, 19.64, 18.32, 18.56, 18.56, 17.74, 19.08, 18.63, 18.93,
18.63, 18.88, 18.5, 23.09, 25.66, 47.21, 92.64, 97.13, 73.73,
39.32, 31.46, 20.8, 23.45, 17.59, 16.96, 14.29, 15.21, 15.64,
15.26, 12.52, 13.18, 14.12, 13.92, 12.32, 13.73, 12.01, 13.84,
12.42, 13.92, 13.26, 15.01, 13.54, 14.6, 17.16, 18.37, 20.3,
19.08, 19.08, 19.35, 17.49, 18.77, 17.12, 16.38, 16.12, 15.7,
15.7, 16.27, 15.08, 14.79, 15.18, 14.6, 18.38, 22.93, 28.6, 26.23,
26.69, 26.29, 23.38, 17.38, 13.94, 14.6, 13.73, 14.41, 13.08,
13.84, 10.42, 15.08, 15.08, 15.48, 16.04, 15.67, 12.62, 12.89,
12.12)), row.names = c(NA, -150L), class = c("tbl_df", "tbl",
"data.frame"))
>Solution :
You have duplicated times because there are multiple days in your data. Duplicated x-values due to the presence of multiple (unresolved) groups is a typical causefor the spikiness of the trend.
If you include the day in the group, you see separate tracks for every day without the spikiness.
library(ggplot2)
library(lubridate)
# df <- structure(...) # omitted for brevity
ggplot(df, aes(x=Time, y=Price, group= interaction(Band, day(Date)))) +
geom_line(aes(color=Band), lwd=1)+
labs(x="Time (hours)", y="Price", title="")+
theme_bw() +
theme(axis.text.x = element_text(angle = 90, hjust = 1)) +
scale_y_continuous(expand = c(0,0))
Created on 2022-01-19 by the reprex package (v2.0.1)
Alternatively you can use aes(Date, Price, group = Band) instead to visualse the timecourse:
