
Metabolite Quality Control
quality_control.Rd
This function is a wrapper function that performs the key quality controls steps on a metabolomics data set. Key principles: 1. keep the source underlying data as it is 2. copy the source data to a new data layer called qcing for processing 3. build an exclusion list, accumulating codes for exclusion reasons 4. make any adjustments needed in the destination copy of the data, flag these in the exclusion list 5. copy the final result to a data layer called post_qc 6. return the Metabolites object with the newly populated data layers
Usage
quality_control(
metaboprep,
source_layer = "input",
sample_missingness = 0.5,
feature_missingness = 0.5,
total_peak_area_sd = 5,
outlier_udist = 5,
outlier_treatment = "leave_be",
winsorize_quantile = 1,
tree_cut_height = 0.5,
pc_outlier_sd = 5,
sample_ids = NULL,
feature_ids = NULL,
features_exclude_but_keep = NULL
)
Arguments
- metaboprep
an object of class Metabolites
- source_layer
character, the data layer to summarise
- sample_missingness
numeric 0-1, percentage of data missingness which should prompt exclusion of a sample
- feature_missingness
numeric 0-1, percentage of data missingness which should prompt exclusion of a feature
- total_peak_area_sd
numeric, number of TPA SD after which a sample would be excluded
- outlier_udist
the unit distance in SD or IQR from the mean or median estimate, respectively outliers are identified at. Default value is 5.
- outlier_treatment
character, how to handle outlier data values - options 'leave_be', 'turn_NA', or 'winsorize'
- winsorize_quantile
numeric, quantile to winsorize to, only relevant if 'outlier_treatment'='winsorize'
- tree_cut_height
numeric, the threshold for feature independence in hierarchical clustering. Default is 0.5.
- pc_outlier_sd
numeric, number of PCA SD after which a sample would be excluded
- sample_ids
character, vector of sample ids to work with
- feature_ids
character, vector of feature ids to work with
- features_exclude_but_keep
character, vector of feature id indicating features to exclude from the sample and PCA summary analysis but keep in the data, OR a name of a logical column in the features data indicating the same