Introduction

respR was designed to be an end-to-end solution for analysing data and reporting analyses from any and all aquatic respirometry experiments regardless of the equipment used. Therefore, it is system-agnostic; the data need only be put into a very simple structure - numeric time against oxygen in any common units in a data.frame - to allow a full analysis to be conducted. In fact the entire package, with the exception of the final conversion step in convert_rate, treats data as unitless so non-aquatic respirometry data or any time-series data can be explored and analysed.

Generic or common importing functions.

To our knowledge, every oxygen probe system allows data to be exported in easily readable formats (e.g. .csv, .txt, .xlsx) which contain the numeric time and oxygen data respR requires. These files are best imported using generic functions after which the relevant columns can be specified when used in respR functions.

There is a wealth of information online about importing data to R. See here, here and here for just a few examples.

The following functions may help with importing your data:

  • read.csv(), read.table(), read.delim() - Generic base R import functions. Also import .txt files. The nrows and skip inputs are particularly useful for specifying how many rows to import and how many to skip at the start of the file.

  • readr - A Tidyverse package for importing tabular data.

  • fread() - In the data.table package. Also imports .txt files. Faster and more efficient than read.csv. Like read.csv, the nrows and skip inputs are particularly useful.

  • readxl - A Tidyverse package for importing Excel files.

  • readLines() - A powerful but crude tool that dumps the entire text content of files. Requires a lot of processing afterwards to get any useful data. A last resort option.

  • janitor::clean_names() - Handy for cleaning up column names, if you want to.

Numeric time data

respR does not work with traditional date-time data (e.g. “2023-03-12 13:46:55”). Instead the time data must be in a numeric form in seconds (by far the most commonly used), minutes, hours or days. The good news is that most export files from oxygen probes systems contain a timestamp or numeric time column already. If they do not, it is relatively easy to convert date-times to a numeric format. See vignette("format_time").

import_file

Note as of respR v2.3.0 this function has been DEPRECATED. It is still fully functional, but import_file will not be updated and will be removed in a future release. Users should move their importing data workflows to use more generic functions such as those detailed above. This gives you much more control and the ability to troubleshoot issues if a problem occurs, rather than waiting for this function to be updated.

For files currently supported, import_file() uses pattern recognition to identify the originating system of the file, imports it, formats columns and column names, and outputs a data frame that can be passed to respR functions.

To repeat: use of this function to prepare the data for use in respR is OPTIONAL and in fact NOT RECOMMENDED. It is a convenience function and mainly intended for those completely new to R. If you are even slightly experienced in R you should know how to import data and structure it to a simple dataframe of time against oxygen. It is ALWAYS better to import files yourself using generic functions. See above.

Supported systems

import_file supports several systems at present, including Firesting, Pyro, PreSens, MiniDOT, Loligo Witrox, Vernier and more. See import_file() for full list.

Checking output and next steps

If the imported data does not contain a numeric time or timestamp column, but only dates and times see vignette("format_time"). After your data is in a paired, numeric time~oxygen structure, it can be passed to inspect() to check the importing or time formatting has worked, look for common errors, and visualise the dataset. See vignette("inspecting").