persim.PersImage

class persim.PersImage(*args, **kwargs)[source]

Initialize a persistence image generator.

Parameters
  • pixels (pair of ints like (int, int)) – Tuple representing number of pixels in return image along x and y axis.

  • spread (float) – Standard deviation of gaussian kernel.

  • specs (dict) –

    Parameters for shape of image with respect to diagram domain. This is used if you would like images to have a particular range. Shaped like:

    {
        "maxBD": float,
        "minBD": float
    }
    

  • kernel_type (string or ..) – TODO: Implement this feature. Determine which type of kernel used in the convolution, or pass in custom kernel. Currently only implements Gaussian.

  • weighting_type (string or ..) – TODO: Implement this feature. Determine which type of weighting function used, or pass in custom weighting function. Currently only implements linear weighting.

Deprecated since version 0.1.5: Replaced with the class persim.PersistenceImager.

__init__(pixels=(20, 20), spread=None, specs=None, kernel_type='gaussian', weighting_type='linear', verbose=True)[source]

Initialize self. See help(type(self)) for accurate signature.

Methods

__init__([pixels, spread, specs, …])

Initialize self.

fit_transform(X[, y])

Fit to data, then transform it.

kernel([spread])

This will return whatever kind of kernel we want to use.

show(imgs[, ax])

Visualize the persistence image

to_landscape(diagram)

Convert a diagram to a landscape (b,d) -> (b, d-b)

transform(diagrams)

Convert diagram or list of diagrams to a persistence image.

weighting([landscape])

Define a weighting function, for stability results to hold, the function must be 0 at y=0.

kernel(spread=1)[source]

This will return whatever kind of kernel we want to use. Must have signature (ndarray size NxM, ndarray size 1xM) -> ndarray size Nx1

show(imgs, ax=None)[source]

Visualize the persistence image

static to_landscape(diagram)[source]

Convert a diagram to a landscape (b,d) -> (b, d-b)

transform(diagrams)[source]

Convert diagram or list of diagrams to a persistence image.

Parameters

diagrams (list of or singleton diagram, list of pairs. [(birth, death)]) – Persistence diagrams to be converted to persistence images. It is assumed they are in (birth, death) format. Can input a list of diagrams or a single diagram.

weighting(landscape=None)[source]

Define a weighting function, for stability results to hold, the function must be 0 at y=0.