# API reference¶

If you’re just getting started, have a look at access.Access or Access Class API (or the Tutorials!) to see the basic structure of the package and its applications.

## Accessibility Class¶

For the full definitions and examples of each method, see individual functions.

 Access(demand_df, demand_value, supply_df[, ...]) Spatial Access Class Access.weighted_catchment([name, ...]) Calculate the catchment area (buffer) aggregate access score. Access.fca_ratio([name, demand_cost, ...]) Calculate the floating catchment area (buffer) ratio access score. Access.two_stage_fca([name, cost, max_cost, ...]) Calculate the two-stage floating catchment area access score. Access.enhanced_two_stage_fca([name, cost, ...]) Calculate the enhanced two-stage floating catchment area access score. Access.three_stage_fca([name, cost, ...]) Calculate the three-stage floating catchment area access score. Access.raam([name, cost, supply_values, ...]) Calculate the rational agent access model. Access.score(col_dict[, name]) Weighted aggregate of multiple already-calculated, normalized access components. Access.create_euclidean_distance([name, ...]) Calculate the Euclidean distance from demand to supply locations. Calculate the Euclidean distance among demand locations. Access.append_user_cost(new_cost_df, origin, ...) Create a user cost, from demand to supply locations. Create a user cost, from supply locations to other supply locations.

## Helper Functions¶

 weights.step_fn(step_dict) Create a step function from a dictionary. weights.gravity(scale, alpha[, min_dist]) Create a gravity function from a scale $$s$$ and $$\alpha$$ parameters as well as an optional minimum distance $$x_\text{min}$$. weights.gaussian(sigma) Create a gaussian weight function, for a specified width, $$\sigma$$.

## Internal Access Functions¶

The access class uses lower-level functions for its internal calculations. In most cases, we do not expect users to call these directly. However, users seeking to understand these calculations and their inputs can still consult the Listing of Internal Access Functions.