[R] Enquiries about time plots in R
Dear all, My name is Maria Lathouri and I am currently doing a PhD at Imperial College of London about time series of environmental variables in surface waters. I am trying to do some time plots with R but it seems that it is not working. The problem is that the time is not regular, for example, a small dataset can be seen below: Date pH 1/02/1998 5.5 5/03/1998 5 8/12/1998 6 1/02/1999 6.1 ... 08/10/20007.2 I have used the function plot(DATE, pH) and then lines(pH), but the line does not join the points. I have used many combinations, e.g. plot(DATE, pH) and then lines(DATE, pH), where I get a plot with full of lines inside or just plot(pH) and then lines(pH) where the line connects the points but in x-axis I do not have the DATE. It says Index from 0 to 80. Do you know if there is a function where I can have in x-axis the DATE (irregular dates) and in y-axis the variable with a continuous line, showing how it changes through time? I know that your time is valuable but I would appreciate it if you could help me. Thank you very much in advance for your time and help. I am looking forward to hearing from you. Sincerely yours Lathouri Maria [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Enquiries about time plots in R
Try this (in reality you would use the commented line in place of the subsequent line) and then read the three zoo vignettes and R News 4/1. library(zoo) library(chron) Lines - Date pH 1/02/1998 5.5 5/03/1998 5 8/12/1998 6 1/02/1999 6.1 08/10/20007.2 # z - read.zoo(myfile.dat, header = TRUE, format = %m/%d/%Y) z - read.zoo(textConnection(Lines), header = TRUE, format = %m/%d/%Y) plot(z) On Wed, Nov 12, 2008 at 10:40 AM, Lathouri, Maria [EMAIL PROTECTED] wrote: Dear all, My name is Maria Lathouri and I am currently doing a PhD at Imperial College of London about time series of environmental variables in surface waters. I am trying to do some time plots with R but it seems that it is not working. The problem is that the time is not regular, for example, a small dataset can be seen below: Date pH 1/02/1998 5.5 5/03/1998 5 8/12/1998 6 1/02/1999 6.1 ... 08/10/20007.2 I have used the function plot(DATE, pH) and then lines(pH), but the line does not join the points. I have used many combinations, e.g. plot(DATE, pH) and then lines(DATE, pH), where I get a plot with full of lines inside or just plot(pH) and then lines(pH) where the line connects the points but in x-axis I do not have the DATE. It says Index from 0 to 80. Do you know if there is a function where I can have in x-axis the DATE (irregular dates) and in y-axis the variable with a continuous line, showing how it changes through time? __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Enquiries about time plots in R
I am trying to do some time plots with R but it seems that it
is not working. The problem is that the time is not regular,
for example, a small dataset can be seen below:
Date pH
1/02/1998 5.5
5/03/1998 5
8/12/1998 6
1/02/1999 6.1
...
08/10/20007.2
I have used the function plot(DATE, pH) and then lines(pH),
but the line does not join the points.
lines() needs the same arguments as plot().
I have used many combinations, e.g. plot(DATE, pH) and then
lines(DATE, pH), where I get a plot with full of lines inside
You are on the right track here. You probably want something like
plot(Date, ph, type=l)
or
plot(Date, ph, type=b)
R will plot in the order of appearance, so you may want to sort
the data.frame before plotting.
x-axis I do not have the DATE. It says Index from 0 to 80.
Have a look at the structure of your data. str() will do that for
you. I suspect that Date is a factor rather than a Date. Use
as.Date() to fix that.
Do you know if there is a function where I can have in x-axis
the DATE (irregular dates) and in y-axis the variable with a
continuous line, showing how it changes through time?
So in summary you probably want something like this:
# make some example data
df - data.frame(
d=c('2008-10-01','2008-10-12','2008-10-5','2008-10-31'),
y=c(12.5, 17, 13.6, 23.345)
)
# convert to Date, sort and plot
df$d - as.Date(df$d)
df - df[order(df$d), ]
plot(df, type='l')
cu
Philipp
--
Dr. Philipp Pagel
Lehrstuhl für Genomorientierte Bioinformatik
Technische Universität München
Wissenschaftszentrum Weihenstephan
85350 Freising, Germany
http://mips.gsf.de/staff/pagel
__
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and provide commented, minimal, self-contained, reproducible code.
