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rio_tiler.expression

rio_tiler.expression

rio-tiler.expression: Parse and Apply expression.

apply_expression 

apply_expression(blocks: Sequence[str], bands: Sequence[str], data: ndarray) -> MaskedArray

Apply rio-tiler expression.

Args:

blocks (sequence): expression for a specific layer.
bands (sequence): bands names.
data (numpy.array):  array of bands.

Returns:

  • MaskedArray –

    numpy.array: output data.

get_expression_blocks 

get_expression_blocks(expression: str) -> list[str]

Split expression in blocks.

Parameters:

  • expression (str) –

    band math/combination expression.

Returns:

  • list ( list[str] ) –

    expression blocks (str).

Examples:

>>> get_expression_blocks("b1/b2;b2+b1")
    ['b1/b2', 'b2+b1']

parse_expression 

parse_expression(expression: str, cast: bool = True) -> tuple

Parse rio-tiler band math expression and extract bands.

Parameters:

  • expression (str) –

    band math/combination expression.

  • cast (bool, default: True ) –

    cast band names to integers (convert to index values). Defaults to True.

Returns:

  • tuple ( tuple ) –

    band names/indexes.

Examples:

>>> parse_expression("b1+b2")
    (1, 2)

>>> parse_expression("B1/B2", cast=False)
    ('1', '2')