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Update jacobi_iteration_method.py
Changed comments, made variable names more understandable.
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@ -117,47 +117,38 @@ def jacobi_iteration_method(
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"""
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denom - a list of values along the diagonal
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val - values of the last column of the table array
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"""
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denom = np.diag(coefficient_matrix)
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"""
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val_last - values of the last column of the table array
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"""
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val_last = table[:, -1]
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"""
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masks - boolean mask of all strings without diagonal
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elements array coefficient_matrix
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ttt - coefficient_matrix array values without diagonal elements
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ind - column indexes for each row without diagonal elements
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arr - list obtained by column indexes from the list init_val
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the code below uses vectorized operations based on
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the previous algorithm on loopss:
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# Iterates the whole matrix for given number of times
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for _ in range(iterations):
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new_val = []
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for row in range(rows):
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temp = 0
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for col in range(cols):
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if col == row:
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denom = table[row][col]
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elif col == cols - 1:
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val = table[row][col]
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else:
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temp += (-1) * table[row][col] * init_val[col]
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temp = (temp + val) / denom
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new_val.append(temp)
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init_val = new_val
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"""
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denom = np.diag(coefficient_matrix)
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val = table[:, -1]
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masks = ~np.eye(coefficient_matrix.shape[0], dtype=bool)
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ttt = coefficient_matrix[masks].reshape(-1, rows - 1)
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"""
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no_diag - coefficient_matrix array values without diagonal elements
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"""
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no_diag = coefficient_matrix[masks].reshape(-1, rows - 1)
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"""
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Here we get 'i_col' - these are the column numbers, for each row
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without diagonal elements, except for the last column.
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"""
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i_row, i_col = np.where(masks)
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ind = i_col.reshape(-1, rows - 1)
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"""
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'i_col' is converted to a two-dimensional list 'ind',
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which will be used to make selections from 'init_val'
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('arr' array see below).
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"""
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# Iterates the whole matrix for given number of times
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for _ in range(iterations):
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arr = np.take(init_val, ind)
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temp = np.sum((-1) * ttt * arr, axis=1)
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new_val = (temp + val) / denom
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temp = np.sum((-1) * no_diag * arr, axis=1)
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new_val = (temp + val_last) / denom
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init_val = new_val
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return new_val.tolist()
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