smpy.coordinates.pixel.PixelSystem

class smpy.coordinates.pixel.PixelSystem

Implementation for pixel coordinates.

Handles data in pixel coordinates, including downsampling for grid creation and safety checks for large pixel dimensions. Provides identity coordinate transformations since no scaling is needed for pixel data.

__init__()

Methods

__init__()
calculate_boundaries(coord1, coord2)	Calculate field boundaries in pixel space.
create_grid(data_df, boundaries, config)	Create shear grid in pixel space.
get_grid_parameters(config)	Get pixel-specific grid parameters.
prepare_data(data_df)	Prepare data for gridding by validating and transforming coordinates.
transform_coordinates(data_df)	Transform pixel coordinates (identity transform).

get_grid_parameters(config)

Get pixel-specific grid parameters.

Extract pixel coordinate system parameters including downsampling factors and safety limits for grid dimensions.

Parameters:

config (dict) – Configuration dictionary containing pixel system settings.

Returns:

grid_params – Grid parameters dictionary containing: - downsample_factor: Factor to reduce grid resolution - max_grid_size: Safety limit for grid dimensions

Return type:

dict

create_grid(data_df, boundaries, config)

Create shear grid in pixel space.

Create a regular grid by binning shear data. Includes automatic adjustment of grid size if dimensions exceed max_grid_size safety limits.

Parameters:

• data_df (pandas.DataFrame) – DataFrame with scaled coordinates and shear data.

• boundaries (dict) – Dictionary with coordinate boundaries.

• config (dict) – Configuration dictionary with pixel parameters.

Returns:

• g1_grid (numpy.ndarray) – 2D array containing binned first shear component values.

• g2_grid (numpy.ndarray) – 2D array containing binned second shear component values.

calculate_boundaries(coord1, coord2)

Calculate field boundaries in pixel space.

Determine coordinate ranges for pixel coordinates and set up appropriate labels. Provides warnings for unusually large coordinate ranges.

Parameters:

• coord1 (numpy.ndarray) – X pixel coordinates.

• coord2 (numpy.ndarray) – Y pixel coordinates.

Returns:

• scaled_boundaries (dict) – Dictionary with coordinate boundaries and labels.

• true_boundaries (dict) – Identical to scaled_boundaries since no scaling needed in pixel space.

Notes

Warns if coordinate ranges are unusually large (>1e5 pixels).

transform_coordinates(data_df)

Transform pixel coordinates (identity transform).

Apply identity transformation to pixel coordinates since no scaling or centering is needed for pixel coordinate systems.

Parameters:

data_df (pandas.DataFrame) – DataFrame with coord1(X), coord2(Y) columns.

Returns:

transformed_df – DataFrame with coord1_scaled, coord2_scaled identical to input coordinates.

Return type:

pandas.DataFrame