LogicleTransform Class

class flowkit.transforms.LogicleTransform(param_t, param_w, param_m, param_a)

Logicle transformation, implemented as defined in the GatingML 2.0 specification:

logicle(x, T, W, M, A) = root(B(y, T, W, M, A) − x)

where B is a modified bi-exponential function defined as:

B(y, T, W, M, A) = ae^(by) − ce^(−dy) − f

The Logicle transformation was originally defined in the publication:

Moore WA and Parks DR. Update for the logicle data scale including operational code implementations. Cytometry A., 2012:81A(4):273–277.

The Logicle scale is the inverse of a modified biexponential function. It provides a Logicle display that maps scale values onto the [0, 1] interval such that the data value param_t is mapped to 1, large data values are mapped to locations similar to a logarithmic scale, and param_a decades of negative data are brought on scale. See the GatingML 2.0 specification for more details.

Parameters:

• param_t – parameter for the top of the linear scale (e.g. 262144)

• param_w – parameter for the approximate number of decades in the linear region

• param_m – parameter for the number of decades the true logarithmic scale approaches at the high end of the scale

• param_a – parameter for the additional number of negative decades

apply(events)

Apply transform to given events.

Parameters:

events – NumPy array of FCS event data

Returns:

NumPy array of transformed events

inverse(events)

Apply the inverse transform to given events.

Parameters:

events – NumPy array of FCS event data

Returns:

NumPy array of inversely transformed events