Add error_prop module with construct_pdf() function [iss #5]

Metallicity_Stack_Commons/error_prop.py

@@ -0,0 +1,18 @@
+from chun_codes import random_pdf, compute_onesig_pdf
+
+def construct_pdf(values, RMS, seed_i=1, n_iter=1000):
+    '''
+    Constructs probability distribution function (PDF) based on input
+    values and their associated uncertainty
+
+    :param values: list or numpy array of values/parameters
+    :param RMS: 1-sigma errors associated with values (same dimension)
+    :param seed_i: integer value for initial seed for np.random. Default: 1
+    :param n_iter: Number of iterations. Default: 1000
+
+    :return pdf_arr: numpy array of size (size of values, n_iter)
+    '''
+
+    pdf_arr = random_pdf(values, RMS, seed_i=seed_i, n_iter=n_iter, silent=False)
+
+    return pdf_arr