linopy.expressions.LinearExpression.has_terms

property LinearExpression.has_terms

Get a boolean array which is true at slots with at least one live term.

A term is live when it references a variable (vars != -1). Slots without any live term arise from outer joins in merge, from reindexing past the original coordinates, or from masking. In contrast to isnull(), the constant is ignored: a slot carrying only a constant has no terms.

Returns:

xr.DataArray

Examples

Mask out constraint rows whose left-hand side has no terms:

>>> import linopy
>>> import pandas as pd
>>> m = linopy.Model()
>>> x = m.add_variables(coords=[pd.RangeIndex(3, name="i")], name="x")
>>> lhs = (1 * x).reindex(i=pd.RangeIndex(5, name="i"))
>>> lhs.has_terms.values
array([ True,  True,  True, False, False])