started script to apply gaussian fit to data

scripts/gaussian_fit.py

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+import numpy as np
+from astropy.modeling import models, fitting
+
+# Using Models
+
+# The astropy.modeling package defines a number of models that are collected under a single namespace as astropy.modeling.models. Models behave like parametrized functions:
+
+from astropy.modeling import models
+g = models.Gaussian1D(amplitude=1.2, mean=0.9, stddev=0.5)
+print(g)
+# Model: Gaussian1D
+# Inputs: ('x',)
+# Outputs: ('y',)
+# Model set size: 1
+# Parameters:
+#     amplitude mean stddev
+#     --------- ---- ------
+#           1.2  0.9    0.5
+#
+# Model parameters can be accessed as attributes:
+
+g.amplitude
+# Parameter('amplitude', value=1.2)
+g.mean
+# Parameter('mean', value=0.9)
+g.stddev
+# Parameter('stddev', value=0.5)
+
+# and can also be updated via those attributes:
+
+g.amplitude = 0.8
+g.amplitude
+# Parameter('amplitude', value=0.8)
+
+# Models can be evaluated by calling them as functions:
+
+g(0.1)
+# 0.22242984036255528
+g(np.linspace(0.5, 1.5, 7))
+# array([ 0.58091923,  0.71746405,  0.7929204 ,  0.78415894,  0.69394278,
+#         0.54952605,  0.3894018 ])
+
+
+
+import numpy as np
+import matplotlib.pyplot as plt
+from astropy.modeling import models, fitting
+
+# Generate fake data
+np.random.seed(0)
+x = np.linspace(-5., 5., 200)
+y = 3 * np.exp(-0.5 * (x - 1.3)**2 / 0.8**2)
+y += np.random.normal(0., 0.2, x.shape)
+
+# Fit the data using a box model
+t_init = models.Trapezoid1D(amplitude=1., x_0=0., width=1., slope=0.5)
+fit_t = fitting.LevMarLSQFitter()
+t = fit_t(t_init, x, y)
+
+# Fit the data using a Gaussian
+g_init = models.Gaussian1D(amplitude=1., mean=0, stddev=1.)
+fit_g = fitting.LevMarLSQFitter()
+g = fit_g(g_init, x, y)
+
+# Plot the data with the best-fit model
+plt.figure(figsize=(8,5))
+plt.plot(x, y, 'ko')
+plt.plot(x, t(x), label='Trapezoid')
+plt.plot(x, g(x), label='Gaussian')
+plt.xlabel('Position')
+plt.ylabel('Flux')
+plt.legend(loc=2)