Contribution process

You can contribute to cytominer through GitHub issues and pull requests.

Issues

If you have a proposal for new functionality for cytominer and would like to discuss it with the team, please file an issue describing the feature you would like to see implemented. We’re happy to discuss it with you.

Additionally, we encourage you to file an issue to report broken or unexpected functionality (a.k.a., “bugs”). Please include information such as the versions of cytominer and R you use, and provide steps to reproduce the behavior. Sometimes this includes generating small data sets. If necessary, you can share them with us via services like Dropbox and Google Drive.

Pull requests

If you have a feature you have implemented for cytominer that you would like to add to the project, please create a pull request and we’ll work with you to incorporate your addition. Please read the section below on extending cytominer and ensure your addition meets the specification and follows this style guide.

Extending cytominer

cytominer defines several high-level functions for manipulating profiling data: aggregate, normalize, transform, and variable_select. Each function accepts a consistent set of parameters: population, variables, and operation. The operation parameter allows the user to specify an exact operation to apply to their data. For example, "standardize" is an operation that can be applied by the normalize function. You can read more about these parameters and the functions in the sections below.

When extending cytominer, it is important to consider which of the four functions the new operation belongs to. You should define the new operation in a new file (R/new_operation.R), and extend its corresponding high-level function to support the operation. Generally, extending a high-level function to support a new operation is straightforward; look for an if block which cases on the operation string and add a case for the new operation. Be sure to document the new operation and also list it as an option in the corresponding high-level function’s operation documentation.

Parameters

variable	description
population	tbl with grouping (metadata) and observation variables.
variables	character vector specifying observation variables.
operation	character string specifying a specific method to use.
sample*	tbl containing sample that is used by some operation methods.
strata*	character vector specifying grouping variables.
...	optional arguments passed to the operation

* these parameters may not be required by the function and are omitted. If these are required for new functionality, please extend the high-level function signature to include the parameter with a sane default (e.g., NULL).

Aggregate

Aggregate data based on given grouping.

aggregate <- function(population, variables, strata, 
                      operation = "mean",
                      univariate = TRUE, ...) { ... }

univariate is a boolean specifying whether the aggregation function is univariate or multivariate.

Example

population <- tibble::data_frame(
   Metadata_group = c("control", "control", "control", "control",
                      "experiment", "experiment", "experiment",
                      "experiment"),
   Metadata_batch = c("a", "a", "b", "b", "a", "a", "b", "b"),
   AreaShape_Area = c(10, 12, 15, 16, 8, 8, 7, 7)
 )
variables <- c("AreaShape_Area")
strata <- c("Metadata_group", "Metadata_batch")
aggregate(population, variables, strata, operation = "mean")

Normalize

Normalize observation variables based on the specified normalization method.

normalize <- function(population, variables, strata, sample,
                      operation = "standardize", ...) { ... }

Example

suppressMessages(suppressWarnings(library(magrittr)))
population <- tibble::data_frame(
   Metadata_group = c("control", "control", "control", "control",
                      "experiment", "experiment", "experiment", "experiment"),
   Metadata_batch = c("a", "a", "b", "b", "a", "a", "b", "b"),
   AreaShape_Area = c(10, 12, 15, 16, 8, 8, 7, 7)
 )
variables <- c('AreaShape_Area')
strata <- c('Metadata_batch')
sample <- population %>% dplyr::filter(Metadata_group == 'control')
cytominer::normalize(population, variables, strata, sample, operation = "standardize")

Transform

Transform observation variables based on the specified transformation method.

transform <- function(population, variables,
                      operation = "generalized_log", ...) { ... }

Example

population <- tibble::data_frame(
   Metadata_Well = c("A01", "A02", "B01", "B02"),
   Intensity_DNA = c(8, 20, 12, 32)
 )
variables <- c("Intensity_DNA")
transform(population, variables, operation = "generalized_log")

Variable select

Select observation variables based on the specified variable selection method.

variable_select <- function(population, variables,
                            sample = NULL,
                            operation = "variance_threshold", ...) { ... }

Example

suppressMessages(suppressWarnings(library(magrittr)))
population <- tibble::data_frame(
   x = rnorm(100),
   y = rnorm(100)/1000
 )  
population %<>% dplyr::mutate(z = x + rnorm(100) / 10)
sample <- population %>% dplyr::slice(1:30) 
variables <- c("x", "y", "z")
operation <- "correlation_threshold"
cor(sample)

# `x` and `z` are highly correlated; one of them will be removed
head(population)
futile.logger::flog.threshold(futile.logger::ERROR)
variable_select(population, variables, sample, operation) %>% head()