Newbie to RStudio - help with date import and transform

[GooberBoy3107]

Hi all. I am not a programmer, but through a stepwise approach have learned basic functions of RStudio from readings in the community and Google. My goal is to make a PDF report containing many plots for my large data sets. I currently do this in excel which is painfully slow and ultimately I want to analyze and update my data in realtime (every day) over the 3-4 week study period - this allows us to recognize trends during studies.

Using a small test file (.txt format) and ggplot, I have been able to produce several plots in a PDF file; all my plots use time (days) since start of study as the x-axis.

My next step, and the one which I am stuck on, it working with dates in the dataset to compute time since start of study; this new variable would be my X-axis data for all plots. I have attached a test file that I am working with. Format of dataset is date, hours, mins, secs, V1, V2. I am able to change the date to any format (YYYY-MM-DD, dd/MM/YY) before importing into RStudio - I have tried many different options both in format and RStudio import options (ie. read table, csv)

What I want to do is create a new variable (NewVar) from dataset location [1,1] (ie. the first date the study began) and transform the date to a number. Was trying this:

NewVar <- dataset [1,1]
transformed.dataset <- transform(dataset, NewDate = V1 - NewVar)

• V1= date column

The errors I receive, depending upon how I import / arrange date are either :

• In Ops.factor(V1, NewVar) : ‘-’ not meaningful for factors
• non-numeric argument to binary operator

I saw online examples on how to calculate timediff, but none that involve transform function. I'm guessing I'm not presenting the date to Rstudio in a format that it can perform a mathematical function.

My ultimate goal is to add days (from date calculation) + time of day (hh,mm,ss as a fraction of a day) to produce an X-value for each variable ; I have worked out the time of day function

Any help would be appreciated. I can provide more code if needed

Thanks in advance, GooberBoy

[martin.R]

Using transform is not really recommended. See the warning under ?transform

For date manipulations you can use lubridate:

Make Dealing with Dates a Little Easier

Possibly hms, too, if you need it:

GitHub - tidyverse/hms: A simple class for storing time-of-day values

[andresrcs]

@GooberBoy3107

Any help would be appreciated. I can provide more code if needed

Providing a reproducible example is not only a good thing to do, it also increases your chances of getting help.

Could you ask this with a minimal REPRoducible EXample (reprex)? A reprex makes it much easier for others to understand your issue and figure out how to help.

If you've never heard of a reprex before, you might want to start by reading this FAQ:

FAQ: How to do a minimal reproducible example ( reprex ) for beginners

A minimal reproducible example consists of the following items: A minimal dataset, necessary to reproduce the issue The minimal runnable code necessary to reproduce the issue, which can be run on the given dataset, and including the necessary information on the used packages. Let's quickly go over each one of these with examples: Minimal Dataset (Sample Data) You need to provide a data frame that is small enough to be (reasonably) pasted on a post, but big enough to reproduce your issue. Let's say, as an example, that you are working with the iris data frame head(iris) #> Sepal.Length Sepal.Width Petal.Length Petal.Width Species #> 1 5.1 3.5 1.4 0.…

[GooberBoy3107]

lubridate library worked! thanks for guidance Martin.