IOSS 2.0
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Ioss_Doxygen.h
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1
2// clang-format off
3
4/*! \mainpage IOSS API Documentation
5
6\section avail Availability
7
8The IOSS library source code is available on Github at
9https://github.com/sandialabs/seacas
10
11For bug reports, documentation errors, and enhancement suggestions, contact:
12- Gregory D. Sjaardema
13- WEB: https://github.com/sandialabs/seacas
14- EMAIL: gdsjaar@sandia.gov
15- EMAIL: gsjaardema@gmail.com
16- PHONE: (505) 844-2701 (office)
17
18\section db_types Database Types
19
20The IOSS system supports multiple database formats. The default format is the Sandia-developed Exodus format. The list below shows all supported
21database input and/or output formats. Not all of these may be available on all builds; the supported databases on a particular installation can be
22determined by running the `io_info --config` program.
23
24Type | Input/Output | Description
25-----------------|---------------|--------------------------
26exodus | Input/Output | Sandia-developed database system for unstructured mesh input/output (https://sandialabs.github.io/seacas-docs/sphinx/html/index.html#exodus-library)
27cgns | Input/Output | CFD General Notation System (https://cgns.github.io/)
28generated | Input | Generate an unstructured hex/shell mesh using a token string (Iogn::GeneratedMesh::GeneratedMesh)
29textmesh | Input | Generate an unstructured mesh using a token string
30heartbeat | Output | A text based output for global values
31pamgen | Input | (https://trilinos.github.io/pamgen.html)
32gen_struc | Input | Generate a structured mesh using a token string (IxJxK)
33catalyst_exodus | Output | Visualization pipeline, exodus-based
34catalyst_cgns | Output | Visualization pipeline, cgns-based
35null | Output | No data written to disk, no calculations done by ioss
36exonull | Output | No data written to disk, but uses all of the exodus io database infrastructure/calculations
37adios | Input/Output | Adaptable Input/Output system, (https://adios2.readthedocs.io/en/latest/)
38faodel | Input/Output | (https://github.com/faodel/faodel)
39exodusii | Input/Output | alias for exodus
40genesis | Input/Output | alias for exodus
41par_cgns | Input/Output | alias for parallel CGNS
42
43\section properties Properties
44
45## General Properties
46
47 Property | Value | Description
48 ----------|:--------:|------------
49 LOGGING | on/[off] | enable/disable logging of field input/output
50 LOWER_CASE_VARIABLE_NAMES | [on]/off | Convert all variable names read from input database to lowercase; replace ' ' with '_'
51 USE_GENERIC_CANONICAL_NAMES | on/[off] | use `block_{id}` as canonical name of an element block instead of the name (if any) stored on the database. The database name will be an alias.
52 IGNORE_DATABASE_NAMES | on/[off] | Do not read any element block, nodeset, ... names if they exist on the database. Use only the canonical generated names (entitytype + _ + id)
53 IGNORE_ATTRIBUTE_NAMES | on/[off] | Do not read the attribute names that may exist on an input database. Instead for an element block with N attributes, the fields will be named `attribute_1` ... `attribute_N`
54 MINIMIZE_OPEN_FILES | on/[off] | If on, then close file after each timestep and then reopen on next output
55 SERIALIZE_IO | integer | The number of files that will be read/written to simultaneously in a parallel file-per-rank run.
56
57## Auto-Decomposition-Related Properties
58
59 Property | Value | Description
60-----------------|:------:|-----------------------------------------------------------
61MODEL_DECOMPOSITION_METHOD | {method} | Decompose a DB with type `MODEL` using `method`
62RESTART_DECOMPOSITION_METHOD | {method} | Decompose a DB with type `RESTART_IN` using `method`
63DECOMPOSITION_METHOD | {method} | Decompose all input DB using `method`
64PARALLEL_CONSISTENCY | [on]/off | On if the client will call Ioss functions consistently on all processors. If off, then the auto-decomp and auto-join cannot be used.
65RETAIN_FREE_NODES | [on]/off | In auto-decomp, will nodes not connected to any elements be retained.
66LOAD_BALANCE_THRESHOLD | {real} [1.4] | CGNS-Structured only -- Load imbalance permitted Load on Proc / Avg Load
67DECOMPOSITION_EXTRA | {name},{multiplier} | Specify the name of the element map or variable used if the decomposition method is `map` or `variable`. If it contains a comma, the value following the comma is used to scale (divide) the values in the map/variable. If it is 'auto', then all values will be scaled by `max_value/processorCount`
68
69### Valid values for Decomposition Method
70
71Method | Description
72:---------:|-------------------
73rcb | recursive coordinate bisection
74rib | recursive inertial bisection
75hsfc | hilbert space-filling curve
76metis_sfc | metis space-filling-curve
77kway | metis kway graph-based
78kway_geom | metis kway graph-based method with geometry speedup
79linear | elements in order first n/p to proc 0, next to proc 1.
80cyclic | elements handed out to id % proc_count
81random | elements assigned randomly to processors in a way that preserves balance (do not use for a real run)
82map | the specified element map contains the mapping of elements to processor. Uses 'processor_id' map by default; otherwise specify name with `DECOMPOSITION_EXTRA` property
83variable | the specified element variable contains the mapping of elements to processor. Uses 'processor_id' variable by default; otherwise specify name with `DECOMPOSITION_EXTRA` property
84external | Files are decomposed externally into a file-per-processor in a parallel run.
85
86## Output File Composition -- Single File output from parallel run instead of file-per-processor
87
88 Property | Value
89-----------------|:------:
90COMPOSE_RESTART | on/[off]
91COMPOSE_RESULTS | on/[off]
92PARALLEL_IO_MODE | netcdf4, hdf5, pnetcdf, (mpiio and mpiposix are deprecated)
93
94## Properties Related to byte size of reals and integers
95
96 Property | Value | Description
97-----------------------|:------:|-----------------------------------------------------------
98 INTEGER_SIZE_DB | [4] / 8 | byte size of integers stored on the database.
99 INTEGER_SIZE_API | [4] / 8 | byte size of integers used in api functions.
100 REAL_SIZE_DB | 4 / [8] | byte size of floating point stored on the database.
101 REAL_SIZE_API | 4 / [8] | byte size of floating point used in api functions.
102
103## Properties related to field and sideset/surface interpretation
104 Property | Value | Description
105--------------------------|:--------:|-----------------------------------------------------------
106 ENABLE_FIELD_RECOGNITION | [on]/off | Does the IOSS library combine scalar fields into higher-order fields (tensor, vector) based on suffix interpretation.
107 IGNORE_REALN_FIELDS | [off]/on | Do not recognize var_1, var_2, ..., var_n as an n-component field. Keep as n scalar fields. Currently ignored for composite fields.
108 FIELD_SUFFIX_SEPARATOR | char / '_'| The character that is used to separate the base field name from the suffix. Default is underscore.
109 FIELD_STRIP_TRAILING_UNDERSCORE | on / [off] | If `FIELD_SUFFIX_SEPARATOR` is empty and there are fields that end with an underscore, then strip the underscore. (`a_x`, `a_y`, `a_z` is vector field `a`).
110 IGNORE_ATTRIBUTE_NAMES | on/[off] | Do not read the attribute names that may exist on an input database. Instead for an element block with N attributes, the fields will be named `attribute_1` ... `attribute_N`
111 SURFACE_SPLIT_TYPE | {type} | Specify how to split sidesets into homogeneous sideblocks. Either an integer or string: 1 or `TOPOLOGY`, 2 or `BLOCK`, 3 or `NO_SPLIT`. Default is `TOPOLOGY` if not specified.
112 DUPLICATE_FIELD_NAME_BEHAVIOR | {behavior} | Determine how to handle duplicate incompatible fields on a database. Valid values are `IGNORE`, `WARNING`, or `ERROR` (default). An incompatible field is two or more fields with the same name, but different sizes or roles or types.
113
114## Output Database-Related Properties
115 Property | Value | Description
116-----------------|:------:|-----------------------------------------------------------
117 OMIT_QA_RECORDS | on/[off] | Do not output any QA records to the output database.
118 OMIT_INFO_RECORDS | on/[off] | Do not output any INFO records to the output database.
119 RETAIN_EMPTY_BLOCKS | on/[off] | If an element block is completely empty (on all ranks) should it be written to the output database.
120 VARIABLE_NAME_CASE | upper/lower | Should all output field names be converted to uppercase or lowercase. Default is leave as is.
121 FILE_TYPE | [netcdf], netcdf4, netcdf-4, hdf5 | Underlying file type (bits on disk format)
122 COMPRESSION_METHOD | [zlib], szip | The compression method to use. `szip` only available if HDF5 is built with that supported.
123 COMPRESSION_LEVEL | [0]-9 | If zlib: In the range [0..9]. A value of 0 indicates no compression, will automatically set `file_type=netcdf4`, recommend <=4
124 COMPRESSION_LEVEL | 4-32 | If szip: An even number in the range 4-32, will automatically set `file_type=netcdf4`.
125 COMPRESSION_SHUFFLE | on/[off] |to enable/disable hdf5's shuffle compression algorithm.
126 MAXIMUM_NAME_LENGTH | [32] | Maximum length of names that will be returned/passed via api call.
127 APPEND_OUTPUT | on/[off] | Append output to end of existing output database
128 APPEND_OUTPUT_AFTER_STEP | {step}| Max step to read from an input db or a db being appended to (typically used with APPEND_OUTPUT)
129 APPEND_OUTPUT_AFTER_TIME | {time}| Max time to read from an input db or a db being appended to (typically used with APPEND_OUTPUT)
130 FILE_PER_STATE | on/[off] | Put data for each output timestep into a separate file.
131 CYCLE_COUNT | {cycle} | If using FILE_PER_STATE, then use {cycle} different files and then overwrite. Otherwise, there will be a maximum of {cycle} time steps in the file. See below.
132 OVERLAY_COUNT | {overlay}| If using FILE_PER_STATE, then put {overlay} timesteps worth of data into each file before going to next file. Otherwise, each output step in the file will be overwritten {overlay} times. See below.
133 ENABLE_DATAWARP | on/[off] | If the system supports Cray DataWarp (burst buffer), should it be used for buffering output files.
134
135### Cycle and Overlay Behavior:
136(Properties `CYCLE_COUNT`, `OVERLAY_COUNT`, and `FILE_PER_STATE`)
137The `overlay` specifies the number of output steps which will be
138overlaid on top of the currently written step before advancing to the
139next step on the database.
140
141For example, if output every 0.1 seconds and the overlay count is
142specified as 2, then IOSS will write time 0.1 to step 1 of the
143database. It will then write 0.2 and 0.3 also to step 1. It will
144then increment the database step and write 0.4 to step 2 and overlay
1450.5 and 0.6 on step 2. At the end of the analysis, (assuming it runs
146to completion), the database would have times 0.3, 0.6, 0.9,
147... However, if there were a problem during the analysis, the last
148step on the database would contain an intermediate step.
149
150The `cycle_count` specifies the number of restart steps which will be
151written to the restart database before previously written steps are
152overwritten. For example, if the `cycle` count is 5 and output is
153written every 0.1 seconds, IOSS will write data at times 0.1, 0.2,
1540.3, 0.4, 0.5 to the database. It will then overwrite the first step
155with data from time 0.6, the second with time 0.7. At time 0.8, the
156database would contain data at times 0.6, 0.7, 0.8, 0.4, 0.5. Note
157that time will not necessarily be monotonically increasing on a
158database that specifies the cycle count.
159
160The cycle count and overlay count can both be used at the same time
161also. The basic formula is:
162```
163 db_step = (((output_step - 1) / overlay) % cycle) + 1
164```
165where `output_step` is the step that this would have been on the
166database in a normal write (1,2,3,....) and `db_step` is the step
167number that this will be written to.
168
169If you only want the last step available on the database,
170use `set_cycle_count(1)`.
171
172If `FILE_PER_STATE` is specified, then `cycle` specifies the number of
173separate files which will be created and `overlay` specifies how many
174timesteps will be written to each file. If we have `cycle=2` and
175`overlay=3` and the code is outputting every 0.1 seconds, we will get
1760.1, 0.2, 0.3 in the first file; 0.4, 0.5, 0.6 in the second
177file. Then, the first file will be reopened and steps 0.7, 0.8, and
1780.9 will be written to the first file.
179
180
181## Properties for the heartbeat output
182 Property | Value | Description
183-----------------------|:------:|-----------------------------------------------------------
184 FILE_FORMAT | [default], spyhis, csv, ts_csv, text, ts_text | predefined formats for heartbeat output. The ones starting with `ts_` output timestamps.
185 FLUSH_INTERVAL | int | Minimum time interval between flushing heartbeat data to disk. Default is 10 seconds
186 TIME_STAMP_FORMAT | [%H:%M:%S] | Format used to format time stamp. See strftime man page
187 SHOW_TIME_STAMP | on/off | Should the output lines be preceded by the timestamp
188 FIELD_SEPARATOR | [, ] | separator to be used between output fields.
189 FULL_PRECISION | on/[off] | output will contain as many digits as needed to fully represent the doubles value. FIELD_WIDTH will be ignored for doubles if this is specified.
190 PRECISION | -1..16 [5] | Precision used for floating point output. If set to `-1`, then the output will contain as many digits as needed to fully represent the doubles value. FIELD_WIDTH will be ignored for doubles if precision is set to -1.
191 FIELD_WIDTH | 0.. | Width of an output field. If 0, then use natural width.
192 SHOW_LABELS | on/[off] | Should each field be preceded by its name (ke=1.3e9, ie=2.0e9)
193 SHOW_LEGEND | [on]/off | Should a legend be printed at the beginning of the output showing the field names for each column of data.
194 SHOW_TIME_FIELD | on/[off] | Should the current analysis time be output as the first field.
195
196## Experimental / Special Purpose
197
198 Property | Value | Description
199-----------------------|:------:|-----------------------------------------------------------
200MEMORY_READ | on/[off] | experimental
201MEMORY_WRITE | on/[off] | experimental
202ENABLE_FILE_GROUPS | on/[off] | experimental
203MINIMAL_NEMESIS_INFO | on/[off] | special case, omit all nemesis data except for nodal communication map
204OMIT_EXODUS_NUM_MAPS | on/[off] | special case, do not output the node and element numbering map.
205EXODUS_CALL_GET_ALL_TIMES| [on] / off | special case -- should the `ex_get_all_times()` function be called. See below.
206
207* `EXODUS_CALL_GET_ALL_TIMES`: Typically only used in `isSerialParallel`
208mode and the client is responsible for making sure that the step times
209are handled correctly. All databases will know about the number of
210timesteps, but if the `ex_get_all_times()` function call is skipped, then
211the times on that database will all be zero. The use case is that in `isSerialParallel`,
212each call to `ex_get_all_times()` for all files is performed
213sequentially, so if you have hundreds to thousands of files, the time
214for the call is additive and since timesteps are record variables in
215netCDF, accessing the data for all timesteps involves lseeks
216throughout the file.
217
218
219## Debugging / Profiling
220
221 Property | Value | Description
222 ----------|:--------:|------------
223 LOGGING | on/[off] | enable/disable logging of field input/output
224 ENABLE_TRACING | on/[off] | show memory and elapsed time during some IOSS calls (mainly decomp).
225 DECOMP_SHOW_PROGRESS | on/[off] | use `ENABLE_TRACING`.
226 DECOMP_SHOW_HWM | on/[off] | show high-water memory during autodecomp
227 IOSS_TIME_FILE_OPEN_CLOSE | on/[off] | show elapsed time during parallel-io file open/close/create
228 CHECK_PARALLEL_CONSISTENCY | on/[off] | check Ioss::GroupingEntity parallel consistency
229 TIME_STATE_INPUT_OUTPUT | on/[off] | show the elapsed time for reading/writing each timestep's data
230
231## Setting properties via an environment variable
232
233Although the properties are usually accessed internally in the
234application calling the IOSS library, it is possible to set the
235properties externally prior to running the application via the setting
236of the environment variable `IOSS_PROPERTIES`. The value of the
237variable is one or more colon-separated property/property-value pairs.
238For example, to set the `DECOMPOSITION_METHOD` and the `FILE_TYPE`
239externally, the following would be used:
240```
241 export IOSS_PROPERTIES="DECOMPOSITION_METHOD=rib:FILE_TYPE=netcdf4"
242```
243If the environment variable is set correctly, there should be an
244informational message output during running of the application similar
245to:
246```
247 IOSS: Adding property 'DECOMPOSITION_METHOD' with value 'rib'
248 IOSS: Adding property 'FILE_TYPE' with value 'netcdf4'
249```
250
251\section license License
252The IOSS library is licensed under the BSD open source license.
253
254 Copyright(C) 1999-2021 National Technology & Engineering Solutions
255 of Sandia, LLC (NTESS). Under the terms of Contract DE-NA0003525 with
256 NTESS, the U.S. Government retains certain rights in this software.
257
258 See packages/seacas/LICENSE for details
259
260 Redistribution and use in source and binary forms, with or without
261 modification, are permitted provided that the following conditions are
262 met:
263
264 * Redistributions of source code must retain the above copyright
265 notice, this list of conditions and the following disclaimer.
266
267 * Redistributions in binary form must reproduce the above
268 copyright notice, this list of conditions and the following
269 disclaimer in the documentation and/or other materials provided
270 with the distribution.
271
272 * Neither the name of NTESS nor the names of its
273 contributors may be used to endorse or promote products derived
274 from this software without specific prior written permission.
275
276 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
277 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
278 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
279 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
280 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
281 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
282 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
283 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
284 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
285 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
286 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
287
288*/
289
290// clang-format on