Temperature curve in R

Question

I'd like to create two temperature curves in one plot. My Dataframe looks like this:

temp <- read.table(text = "     Time        Temp1       Temp2
                           1  00:00     18.62800    18.54458
                           2   00:10     18.60025    18.48283
                           3   00:20     18.57250    18.36767
                           4   00:30     18.54667    18.36950
                           5   00:40     18.51483    18.36550
                           6   00:50     18.48325    18.34783
                           7   01:00     18.45733    18.22625
                           8   01:10     18.43767    18.19067
                           9   01:20     18.41583    18.22042
                           10  01:30     18.39608    18.21225
                           11  01:40     18.37625    18.18658
                           12  01:50     18.35633    18.05942
                           13  02:00     18.33258    18.04142", header = T)

How can I get clean curves (no edges on the lines like a linechart) by only showing each hour (24 hours) on the x-axis? Im thinking about something with ggplot2 but I'm still learning R basics.

What exactly do you mean by "clean curves"? Do you want to summarize your data before plotting? — MrFlick, Aug 21 '17 at 15:06
Sorry for the mess and thanks for the edit. I want to get a Temperature chart which only shows each hour of a day and not every 10 minutes like in my dataframe. — Takujaki, Aug 21 '17 at 15:07
So, do you want get rid of the values that are not full hours or do you want the x-axis labels to only show full hours? — elevendollar, Aug 21 '17 at 15:14
In addition, do you want average values, or just the actual values of the full hours? — loki, Aug 21 '17 at 15:15
I would use the actual values if the full hours for getting a simple result, but if it is not to complicated I would rather use all values and then only show the full hours in the x-axis — Takujaki, Aug 21 '17 at 15:20

score 2 · Accepted Answer · answered Aug 21 '17 at 15:44

2

If you want to plot all values but only have full hours as x-axis labels you can plot the data with the ggplot package and use the scale_x_discrete() option to specify the breaks.

library(ggplot2)

is_full_time <- grepl(':00', temp$Time)
ggplot(temp, aes(x = Time, y = Temp1, group = 1)) + geom_line() + scale_x_discrete(breaks = temp$Time[is_full_time])

http://ggplot2.tidyverse.org/reference/scale_discrete.html

answered Aug 21 '17 at 15:44

elevendollar

1,115
10
19

Wouldn't this let the ggplot object grow unnecessarily since you put all data in there? – loki Aug 21 '17 at 16:09
Hey @loki, wheather it is necessary depends on if you think the data between full hours is necessary to plot and adds more information for the viewer of the plot. The difference in this particular example is less than 1000 bytes if you are actually storing the object. – elevendollar Aug 22 '17 at 08:12

loki · Answer 2 · 2017-08-21T15:42:44.090

We can use the tidyverse for this. First we "clean" the data from all unnecessary rows by only taking time values with 00 minutes and then we use a ggplot to visualize the temperatures.

library(tidyverse)

cleanTemp <- temp %>% filter(grepl(pattern = ":00", Time))

ggplot(cleanTemp, aes(x = Time, y = Temp1, group = 1)) + 
  geom_line()

Temp2 can be added to the plot with

geom_line(aes(y = Temp2), color = "red")

you can also use lubridate to subset the Time column:

temp$Time <- hm(temp$Time)
cleanTemp <- temp[minute(temp$Time) == 0,]

Temperature curve in R

2 Answers2

Linked