How can I plot output from a function which returns multiple values in Python?

问题

Short intro

I'm calculating and plotting spectral energy of planets orbiting pulsar from given data.

I have previously ordered all data in a list variations with dimensions [172, 2] (172 rows and 2 columns).

Firstly, I have to calculate parameters of a presupposed model and spectral energy accordingly (from those very parameters).

To do that, I defined a function under which I defined the presupposed model and find_fit function which takes the model and variations data.

Code

 var('a, b, t')

def spectrum(omega):

    model = a*sin(omega*t) + b*cos(omega*t)
    fit = find_fit(variations, model, parameters= [a, b], variables = [t], solution_dict = True)
    sp_en = ((fit[a])**2 + (fit[b])**2)/2

    return fit[a], fit[b], sp_en

Then I call the function and print values:

c, v, energy = spectrum(20)   #enter arbitray angular frequency here
print "Values for the given angular frequency : \n \n a = %f, b = %f, spectral_energy = %f " % (c, v, energy)

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Now I have to plot only sp_en output.

"Semi-solution"

It is easy to that if a spectrum function return only sp_en. It is sufficient than to write:

var('t')
plot(spectrum(t), (t, 1, 100))

Which returns: energy-omega plot

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The question than is: how do I plot this function if I want to print all three outputs?

回答1:

Just use indexing on the return value from spectrum:

plot(spectrum(t)[2], (t, 1, 100))

回答2:

Just call the plot function with only the energy variable

omega=10
c, v, energy = spectrum(omega)   #enter arbitray angular frequency here
print "Values for the given angular frequency : \n \n a = %f, b = %f, spectral_energy = %f " % (c, v, energy)

plot(energy, (omega, 1, 100))

来源：https://stackoverflow.com/questions/35486820/how-can-i-plot-output-from-a-function-which-returns-multiple-values-in-python