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Regex Fold

The "regexFold" transform gathers columns into key-value pairs using a regular expression.



Type: string

Default: "sample"

asValue Required

Type: string[] | string

A new column name for the extracted values.

columnRegex Required

Type: string[] | string

A regular expression that matches to column names. The regex must have one capturing group that is used for extracting the key (e.g., a sample id) from the column name.


Type: string

An optional regex that matches to fields that should not be included in the new folded data objects.


Given the following data:

SNP foo.AF bar.AF baz.AF
rs99924582 0.3 0.24 0.94
rs22238423 0.92 0.21 0.42

... and configuration:

  "type": "regexFold",
  "columnRegex": ["^(.*)\\.AF$"],
  "asValue": ["VAF"],
  "asKey": "sample"

The matched columns are folded into new data objects. All others are left intact:

SNP sample VAF
rs99924582 foo 0.3
rs99924582 bar 0.24
rs99924582 baz 0.94
rs22238423 foo 0.92
rs22238423 bar 0.21
rs22238423 baz 0.42