human
$$A(t,T) = \Sigma_i A_i P(dI/dt (t)\otimes e^{-t/\tau_i})$$
 ... Can you provide a the Python code you requested?
assistant
#Here is the Python code you requested.
def AofT(time,T, ai, taui):
    return ai*np.exp(-time/taui)/(1.+np.exp(-T/(2*taui)))

from SimPEG import *
import sys
sys.path.append("./DoubleLog/")
from plotting import mapDat

class LinearSurvey(Survey.BaseSurvey):
    nD = None
    def __init__(self, time, **kwargs): 
        self.time = time
        self.nD = time.size
        
    def projectFields(self, u):
        return u

class LinearProblem(Problem.BaseProblem):

    surveyPair = LinearSurvey

    def __init__(self, mesh, G, **kwargs):
        Problem.BaseProblem.__init__(self, mesh, **kwargs)
        self.G = G

    def fields(self, m, u=None):
        return self.G.dot(m)

    def Jvec(self, m, v, u=None):
        return self.G.dot(v)

    def Jtvec(self, m, v, u=None):
        return self.G.T.dot(v)