Spherically symmetric scalar field collapse in any dimension

We describe a formalism and numerical approach for studying spherically symmetric scalar field collapse for an arbitrary spacetime dimension d and cosmological constant Lambda. The prescription uses a double null formalism, and is based on field redefinitions first used to simplify the field equations in generic two-dimensional dilaton gravity. The formalism is used to construct a code in which d and Lambda are input parameters. We reproduce known results in d=4 and d=6 with Lambda=0, and we present new results for d=5 with a zero and negative Lambda.