Module: LocusZoom_MatchFunctions

"Match" test functions used to compare two values for filtering (what to render) and matching (comparison and finding related points across data layers)

How do matching and filtering work?

See the Interactivity Tutorial for details.

Adding a new function

LocusZoom allows users to write their own plugins, so that "does this point match" logic can incorporate user-defined code. (via LocusZoom.MatchFunctions.add('my_function', my_function);)

All "matcher" functions have the call signature (item_value, target_value) => {boolean}

Both filtering and matching depend on asking "is this field interesting to me", which is inherently a problem of making comparisons. The registry allows any arbitrary function (with a field value as the first argument), but that function doesn't have to use either argument.

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Methods

(inner) '!='(item_value, target_value)

Check if two values are not equal. This allows weak comparisons (eg undefined/null), so it can also be used to test for the absence of a value

Parameters:
Name Type Description
item_value
target_value
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(inner) '%'(item_value, target_value)

Modulo: tests for whether the remainder a % b is nonzero

Parameters:
Name Type Description
item_value
target_value
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(inner) '<'(item_value, target_value)

Less-than comparison

Parameters:
Name Type Description
item_value
target_value
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(inner) '<='(item_value, target_value)

Less than or equals to comparison

Parameters:
Name Type Description
item_value
target_value
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(inner) '='(item_value, target_value)

Check if two values are (strictly) equal

Parameters:
Name Type Description
item_value
target_value
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(inner) '>'(item_value, target_value)

Greater-than comparison

Parameters:
Name Type Description
item_value
target_value
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(inner) '>='(item_value, target_value)

Greater than or equals to comparison

Parameters:
Name Type Description
item_value
target_value
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(inner) 'in'(item_value, target_value)

Check whether the provided value (a) is in the string or array of values (b)

This can be used to check if a field value is one of a set of predefined choices Eg, gene_type is one of the allowed types of interest

Parameters:
Name Type Description
item_value

A scalar value
target_value String | Array

A container that implements the includes method
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(inner) 'match'(item_value, target_value)

Partial-match function. Can be used for free text search ("find all gene names that contain the user-entered string 'TCF'")

Parameters:
Name Type Description
item_value String | Array

A container (like a string) that implements the includes method
target_value

A scalar value, like a string
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