Source code for paws.core.operations.PROCESSING.BASIC.ArrayLog

import numpy as np
from collections import OrderedDict

from ... import Operation as opmod 
from ...Operation import Operation

inputs = OrderedDict(x=None)
outputs = OrderedDict(logx=None)

class ArrayLog(Operation):
    """
    Take the base-10 logarithm of any array. 
    Any elements with non-positive values are removed. 
    """

    def __init__(self):
        super(ArrayLog, self).__init__(inputs, outputs)
        self.input_doc['x'] = 'any array'
        self.output_doc['logx'] = 'array of log(x), same size as x, non-positive values replaced with np.nan'

    def run(self):
        x = self.inputs['x']
        # good_vals = elements for which both x and y have defined logarithm
        idx_ok = ((x > 0) & (~np.isnan(x)))
        logx = np.zeros(x.shape)
        logx[idx_ok] = np.log10(x[idx_ok])
        logx[np.invert(idx_ok)] = np.nan
        self.outputs['logx'] = logx