Added example script that creates a material file

Added example script that creates a speos material file from provided decadic absorbance data table

ansys_optical_automation/application/example_create_material_file_from_decadic_absorbance_data.py

@@ -0,0 +1,170 @@
+import re
+import math
+import csv
+import tkinter as tk
+from tkinter import filedialog
+
+
+def convert_line_to_float_list(line: str):
+    """
+    Function to convert a line of float numbers retrieved from a .txt file to a list of floats. Typically a
+    line, when retrieved, is a string of all the characters from the line. First, the function merges the parts of the
+    string that are separated by a blank character, and creates a list of strings where each string contains the number
+    characters that are separated by a blank space in the original line. Then, in case there are elements of this list
+    consisting of solely empty blanks, these elements are removed. Finally, the list of strings is converted to list of
+    floats.
+    :param line: A string with the content of one line from a .txt file. The line should only
+    include float numbers
+    :return: A list of floats. The floats are the ones separated by blank spaces in the line retrieved from the
+    .txt file
+    """
+    # Convert line to list of strings
+    line_str_list = re.split('\t', line)
+
+    # Remove empty elements from list
+    line_str_list = [value for value in line_str_list if value != '']
+
+    # Convert list of strings to list of floats
+    line_float_list = list(map(float, line_str_list))
+    return line_float_list
+
+
+def select_datafile():
+    """
+    Function that opens a dialog window for the user to select the file containing the decadic absorbance data. This
+    file is in principle a txt, xls, xlsx or dat file. The file content must consist of two columns. The first column
+    contains the wavenumber values (cm^-1) and the second column contains the corresponding decadic absorbance values
+    (1 ppm-meter).
+    :return: A string of the full path of the selected file.
+    """
+    root = tk.Tk()
+    root.withdraw()
+    file_path = filedialog.askopenfilename(title="Select file containing decadic absorbance data")
+    return file_path
+
+
+def calculate_transmittance_from_dec_absorbance(dec_absorbance: float):
+    """
+    Function to calculate the transmittance value from the decadic absorbance value of a material at 1ppm per one meter
+    of material.
+    :param dec_absorbance: A float representing the decadic absorbance of a material (usually at a specific wavelength).
+    The decadic absorbance is physically defined as dec_absorbance=I(0)/I(l), where I(0) is the incident light and I(l)
+    the light transmitted through the propagation distance l. NOTE: The relation between absorbance and decadic
+    absorbance is 10^dec_absorbance = exp(absorbance).
+    :return: A float representing the transmittance of a material (usually at a specific wavelength). The transmittance
+    is physically defined as transmittance=I(l)/I(0).
+    """
+    transmittance = 10 ** (-dec_absorbance)     # [ - ] (ppm-meter@296K)
+    return transmittance
+
+
+def calculate_absorption_coef_from_dec_absorbance(dec_absorbance: float):
+    """
+    Function that calculates the absorption coefficient of a material from the decadic absorbance value of a material at
+    1ppm per one meter of material. The absorption coefficient is calculated from the Beer-Lambert law
+    I(l)=I(0)exp(-absorption_coef*l) <=> absorption_coef=-ln(transmittance)/l, where I(0) is the incident light and I(l)
+    the light transmitted through the propagation distance l.
+    :param dec_absorbance: A float representing the decadic absorbance of a material (usually at a specific wavelength).
+    The decadic absorbance is physically defined as dec_absorbance=I(0)/I(l).
+    :return: A float representing the absorption coefficient (mm^-1) of a material (usually at a specific wavelength).
+    NOTE: The relation between absorption coefficient and decadic absorption coefficient is
+    dec_absorption_coef=absorption_coef/ln(10).
+    """
+    transmittance = calculate_transmittance_from_dec_absorbance(dec_absorbance)
+    absorption_coef = -math.log(transmittance) / 1e3    # [mm^-1]
+    return absorption_coef
+
+
+def calculate_wavelength_from_wavenumber(wavenumber: float):
+    """
+    Function that calculates the wavelength (nm) from the wavenumber (cm^-1).
+    :param wavenumber: A float representing the wavenumber value (cm^-1)
+    :return: A float representing the wavelength value (nm)
+    """
+    wavelength = 1e7 / wavenumber   # [nm]
+    return wavelength
+
+
+def load_dec_absorbance_data_to_variable():
+    """
+    Function that locates, opens, and reads the decadic absorbance data file and passes the data into a variable.
+    :return: A list variable containing the decadic absorbance data. Each list element is another list of two floats.
+    These floats are respectively the wavenumber (cm^-1) and the corresponding decadic absorbance (ppm-meter).
+    """
+    file_path = select_datafile()
+    with open(file_path) as f:
+        data_rows = f.readlines()
+    data_rows_list = [convert_line_to_float_list(line) for line in data_rows]
+    return data_rows_list
+
+
+def convert_dec_absorbance_data(dec_absorbance_data: list):
+    """
+    Function that converts the decadic absorbance data to absorption coefficient data in a format that is compatible
+    with the syntax of the speos *.material files.
+    :param dec_absorbance_data: A list variable containing the decadic absorbance data. Each list element is another
+    list of two floats. These floats are respectively the wavenumber (cm^-1) and the corresponding decadic absorbance
+    (ppm-meter).
+    :return: A list variable containing the absorption coefficient data. Each list element is another list of two
+    floats. These floats are respectively the wavelength (nm) and the corresponding absorption coefficient (mm^-1).
+    """
+    absorption_coef_data = [[calculate_wavelength_from_wavenumber(row[0]),
+                             calculate_absorption_coef_from_dec_absorbance(row[1])]
+                            for row in dec_absorbance_data]
+    return absorption_coef_data
+
+
+def setup_material_file_for_speos(absorption_coef_data: list):
+    """
+    A function that creates a Speos *.material file using the provided absorption coefficient data (absorption
+    coefficient wrt wavelength), and the assumption that the material has the refractive index and constringence of
+    atmospheric air. The function first formulates the file's header as a list of strings. Then it merges the header
+    with the absorption coefficient data to create the Speos *.material file with the proper syntax. The file is created
+    in the working directory.
+    :param absorption_coef_data: A list variable containing the absorption coefficient data. Each list element is
+    another list of two floats. These floats are respectively the wavelength (nm) and the corresponding absorption
+    coefficient (mm^-1).
+    :return:
+    """
+    # Set up *.material file for Speos
+    refractive_index = 1.00027716   # Atmospheric air
+    constringence_value = 89.29     # Atmospheric air
+    first_rows = ["OPTIS - Material file v13",
+                  "Material description",
+                  "Isotropic",
+                  "Constringence",
+                  str(refractive_index),
+                  str(constringence_value),
+                  str(len(absorption_coef_data))
+                  ]
+
+    with open('user_defined_material.material', 'w') as g:
+        g.write('\n'.join(first_rows))
+        g.write('\n')
+        wr = csv.writer(g, delimiter=" ", lineterminator="\n")
+        wr.writerows(absorption_coef_data)
+    return
+
+
+def main():
+    """
+    The main function of the example performs in sequence three main operations. Reads a data file containing the
+    spectral decadic absorbance (decadic absorbance wrt wavenumber), then converts the data to a format compatible with
+    the syntax of a speos *.material file, and then creates the respective speos *.material file in the working
+    directory.
+    This operation is useful for the definition of gases with specific spectral (decadic) absorbance provided by a data
+    file.
+    ASSUMPTIONS:
+    - The provided decadic absorbance is at 1 ppm per one meter of material
+    - The provided wavenumber units are [cm^-1]
+    - The material has the refractive index and constringence of atmospheric air
+    :return:
+    """
+    dec_absorbance_data = load_dec_absorbance_data_to_variable()
+
+    absorption_coef_data = convert_dec_absorbance_data(dec_absorbance_data)
+
+    setup_material_file_for_speos(absorption_coef_data)
+
+
+main()