1"""
2
3This file will showcase how you can load line data from arts-cat-data into the
4workspace and do the required setups to perform a simple forward calculations
5using this data
6
7Note that this example presumes that you have set the environment variable
8ARTS_DATA_PATH to contain a path to a local copy of both arts-cat-data and
9arts-xml-data before you import pyarts. Please check that this is the case
10if the example does not work for you. You can easily check if this path is
11set by adding the following two lines at the top of this pyarts-controlfile:
12
13```
14import os
15print(os.environ.get("ARTS_DATA_PATH"))
16```
17
18"""
19
20import pyarts
21import numpy as np
22import matplotlib.pyplot as plt
23
24# Initialize ARTS
25ws = pyarts.workspace.Workspace()
26
27"""
28
29Set ws.abs_species to the species tags that you wish to use. Pure line-by-line
30calculations sets the species by an expanded form of the AFGL tag system in
31ARTS. This example sets the isotopologue to O16-O16, "O2-66", to include all
32lines of said isotopologue into the absorption species tag list
33
34There are many ways to customize this tag. The following things are examples
35of what is possible:
361) Change "O2-66" to "O2". Consequence: Not just the O2-66 isotopologue is
37 included in the absorption species tag list but all molecular oxygen lines
38 are included. Note that "O2-*" is the same thing as "O2".
392) Change "O2-66" into "O2-66,O2-68". Consequence: Not just O2-66 but also
40 the O16-O18 isotopologue is included as the first species tag.
41 Note that for forward calculation purposes, writing ["O2-66,O2-68"] or
42 ["O2-66", "O2-68"] includes the same lines but changes the layout of
43 ws.abs_lines_per_species
443) Change "O2-66" into "O2-66-40e9-120e9". Consequence: Still only the O2-66
45 isotopologue is considered, but all lines below 40 GHz and all lines above
46 120 GHz are considered part of another species tag. Note that you can
47 write your list as ["O2-66-40e9-120e9,O2-66"] to still include all lines,
48 though this would in this particular example be a trivial waste of time
494) Change "O2-66" to "O2-Z-66". Consequence: You will activate Zeeman effect
50 calculations for O2-66. Warning: Zeeman effect calculations are slow
51 because they require several times more calls to core line-by-line
52 functions. Note that one way to speed up these calculations is to combine
53 the tags with one of the examples above. If you write your list of species
54 tags as ["O2-Z-66-110e9-120e9", "O2-66"], only absorption lines between
55 110 and 120 GHz will be treated as Zeeman-affected, but the rest of the
56 lines are still included in the calculations.
575) Change ["O2-66"] to ["O2-66", "H2O-161"]. Consequence: The water
58 isotopologue H1-O16-H1 is added to your list of line-by-line absorption
59 species. Note that you can add as many species as you wish. Also note
60 that you are not allowed to write "O2-66,H2O-161" but must separate this
61 as written at the top of this listitem.
625) Change ["O2-66"] to ["O2-66", "O2"]. Consequence: All oxygen lines are
63 in your list of line-by-line absorption species. Note that you can
64 add as many species as you wish. Also note that you are allowed to
65 write "O2-66,O2".
66
67"""
68ws.absorption_speciesSet(species=["O2-66"])
69
70"""
71
72Load the line data of the absorption tags defined in ws.abs_species into the
73ARTS line catalog at ws.abs_lines_per_species
74
75The line data file is expected to be named as a line-by-line species tag. So
76for our species tag of "O2-66" above, the reading routine will look for the file
77name "lines/O2-66.xml". The search paths for these files prefer paths relative
78to the current working directory above this available elsewhere on the system.
79However, "lines/O2-66.xml" does exist in a fully up-to-date version of
80arts-cat-data (if you ARTS version is recent enough) so it is likely that this
81is the file that is selected for reading.
82
83The resulting ws.abs_lines_per_species will have outer size 1,
84len(ws.abs_lines_per_species.value) == 1, after running this file as provided
85because the size and shape of ws.abs_species is linked to the size and shape
86of ws.abs_lines_per_species.
87
88If you change your tags following one of the examples above, the following
89are the consequences:
901) Change "O2-66" to "O2". ws.abs_lines_per_species will now contain not just
91 O2-66 lines but also other isotopologues. The len of
92 ws.abs_lines_per_species will not change.
932) Change "O2-66" into "O2-66,O2-68". ws.abs_lines_per_species will now
94 contain not just O2-66 lines but also lines of O2-68. If written as
95 ["O2-66,O2-68"] the len of ws.abs_lines_per_species will not change. If
96 written as ["O2-66", "O2-68"] the len of ws.abs_lines_per_species is now 2.
973) Change "O2-66" into "O2-66-40e9-120e9". This will simply limit the number
98 of lines in the line catalog.
994) Change "O2-66" to "O2-Z-66". The line catalog will look exactly the same
100 but the calculations inside will change significantly
1015) Change ["O2-66"] to ["O2-66", "H2O-161"]. The len of
102 ws.abs_lines_per_species is now 2 as the first entry are lines of O2-66 and
103 the second entry are lines of H2O-161
1046) Change ["O2-66"] to ["O2-66", "O2"]. The len of
105 ws.abs_lines_per_species is now 2 as the first entry are lines of O2-66 and
106 the second entry are all other lines of O2. Note therefore that ["O2", "O2-66"]
107 also has the len 2, but that all lines are now in the first entry.
108
109"""
110ws.absorption_bandsReadSpeciesSplitCatalog(basename="lines/")
111
112"""
113
114You should generally always call this after you are done setting up your
115ws.abs_species and ws.abs_lines_per_species. It will deal with the internal
116ARTS setup for you. Note that the flag use_abs_lookup=1 can be passed to this
117method call to set up the agenda for USING the the lookup-table. Without the
118flag, ARTS should be configured correctly either 1) to compute the lookup-table,
119or to 2) compute the absorption on-the-fly
120
121"""
122ws.propagation_matrix_agendaAuto()
123
124"""
125
126Compute absorption
127
128Now we can use the propagation_matrix_agenda to compute the absorption of O2-66.
129We can also use this agenda in more complicated setups that might require
130absorption calculations, but that is for other examples
131
132To just execute the agenda we need to still define its both its inputs and the
133inputs required to initialize the propagation matrix
134
135"""
136
137ws.jacobian_targets = pyarts.arts.JacobianTargets()
138ws.frequency_grid = np.linspace(
139 40e9, 120e9, 11
140) # Frequencies between 40 and 120 GHz
141ws.ray_path_point # No particular POSLOS
142ws.atmospheric_pointInit()
143ws.atmospheric_point.temperature = 295 # At room temperature
144ws.atmospheric_point.pressure = 1e5 # At 1 bar
145ws.atmospheric_point[ws.absorption_species[0]] = (
146 0.21 # At 21% atmospheric Oxygen
147)
148
149# Call the agenda with inputs above
150ws.propagation_matrix_agendaExecute()
151
152# Plot the absorption of this example
153plt.figure(1)
154plt.clf()
155plt.semilogy(ws.frequency_grid.value / 1e9, ws.propagation_matrix)
156plt.xlabel("Frequency [GHz]")
157plt.ylabel("Absorption [1/m]")
158plt.title("O2-66 absorption from examples/arts-cat-data/lines/lines.py")
159
160"""
161That's it! You are done and have reached the end of this example. Everything
162below here is just to ensure that ARTS does not break in the future. It can
163be safely ignored
164
165"""
166# Save test results
167# ws.propagation_matrix.savexml("lines_test_result.xml", type="ascii")
168
169# test that we are still OK
170assert np.allclose(
171 [
172 8.92664373e-06,
173 2.88107577e-05,
174 1.55470464e-03,
175 1.55360514e-03,
176 5.57640699e-05,
177 2.51926728e-05,
178 1.72272988e-05,
179 1.43453057e-05,
180 1.46251762e-05,
181 2.71389841e-05,
182 1.97382384e-04,
183 ],
184 ws.propagation_matrix[:, 0],
185), "O2 Absorption has changed"