# I/O API **URL:** https://forum.cmascenter.org/c/ioapi/5.md [Latest](https://forum.cmascenter.org/latest.md) · [Categories](https://forum.cmascenter.org/categories.md) · [Tags](https://forum.cmascenter.org/tags.md) --- ## [About the I/O API category](https://forum.cmascenter.org/t/about-the-i-o-api-category/16)
**Author:** [@lizadams](https://forum.cmascenter.org/u/lizadams)\ **Replies:** 1\ **Last updated:** [May 22, 2023, 1:56pm UTC](https://forum.cmascenter.org/t/about-the-i-o-api-category/16 "2023-05-22T13:56:36Z")
Need help compiling and using the I/O API? Search topics and/or create a new one that describes your experience. PLEASE READ before posting - #3 --- ## [I/O-API-LARGE won't compile](https://forum.cmascenter.org/t/i-o-api-large-wont-compile/5983)
**Author:** [@bwzelt](https://forum.cmascenter.org/u/bwzelt)\ **Replies:** 2\ **Last updated:** [September 24, 2025, 6:02pm UTC](https://forum.cmascenter.org/t/i-o-api-large-wont-compile/5983 "2025-09-24T18:02:35Z")
I’m trying to create an CMAQ-v55-DDM-3D working environment/code on a RedHat 9.6. I successfully installed netcdf-c-4.9.3, netcdf-fortran-4.6.2, ioap-3.2 and openmpi-5.0.8. Using this environment I’ve compiled CCTM wit… --- ## [I want to know About Automating Data Preprocessing with M3Tools – Any Tips?](https://forum.cmascenter.org/t/i-want-to-know-about-automating-data-preprocessing-with-m3tools-any-tips/5905)
**Author:** [@Zainab](https://forum.cmascenter.org/u/Zainab)\ **Replies:** 1\ **Last updated:** [July 10, 2025, 12:40pm UTC](https://forum.cmascenter.org/t/i-want-to-know-about-automating-data-preprocessing-with-m3tools-any-tips/5905 "2025-07-10T12:40:05Z")
Hey everyone, I have been digging into M3Tools for some air quality data handling, around format conversion and preprocessing. I have got the basics down but I want to know if anyone here has figured out ways to automat… --- ## [I/O API Updates](https://forum.cmascenter.org/t/i-o-api-updates/5737)
**Author:** [@cjcoats](https://forum.cmascenter.org/u/cjcoats)\ **Replies:** 0\ **Last updated:** [April 15, 2025, 1:45pm UTC](https://forum.cmascenter.org/t/i-o-api-updates/5737 "2025-04-15T13:45:39Z")
The currently authoritative site for the I/O API is on GitHub: For source code and downloads: https://github.com/cjcoats/ioapi-3.2 For documentation: https://cjcoats.github.io/ioapi/AA.htm For download git clone https… --- ## [I/O API bin-create "Cannot find mpif.h error"](https://forum.cmascenter.org/t/i-o-api-bin-create-cannot-find-mpif-h-error/5511)
**Author:** [@ganghan2000](https://forum.cmascenter.org/u/ganghan2000)\ **Replies:** 6\ **Last updated:** [January 14, 2025, 9:09pm UTC](https://forum.cmascenter.org/t/i-o-api-bin-create-cannot-find-mpif-h-error/5511 "2025-01-14T21:09:58Z")
Hello, I’m trying to make bin in HiPerGator. This is my module list for compiling I/O API. ufrc 4) netcdf-c/4.9.2 7) netcdf/4.7.2 10) hdf5/1.14.4 intel/2020.0.166 5) nco/4.2.1 8) udunits/2.… --- ## [Issue building m3tools - undefined references](https://forum.cmascenter.org/t/issue-building-m3tools-undefined-references/5364)
**Author:** [@Kylie](https://forum.cmascenter.org/u/Kylie)\ **Replies:** 4\ **Last updated:** [November 23, 2024, 1:24am UTC](https://forum.cmascenter.org/t/issue-building-m3tools-undefined-references/5364 "2024-11-23T01:24:17Z")
Hi all, When I try to run make for m3tools, I have undefined references to “nf\_put\_vara\_int64\_” and “nf\_get\_vara\_int64\_”. How do I determine if this is an issue with my netCDF build or with my IOAPI/m3tools build? If i… --- ## [Land use interpolation issue - IOAPI](https://forum.cmascenter.org/t/land-use-interpolation-issue-ioapi/5308)
**Author:** [@Dimitris\_Karagiannis](https://forum.cmascenter.org/u/Dimitris_Karagiannis)\ **Replies:** 9\ **Last updated:** [November 4, 2024, 2:58pm UTC](https://forum.cmascenter.org/t/land-use-interpolation-issue-ioapi/5308 "2024-11-04T14:58:19Z")
I am using IOAPI to regrid and interpolate MCIP files. The MCIP files are produced by processing WRF output files. There is a problem with the land use values. Land use is an index, not a continuous parameter (like temp… --- ## [IOAPI\_3.2 compiling error](https://forum.cmascenter.org/t/ioapi-3-2-compiling-error/5270)
**Author:** [@haohe.umcp](https://forum.cmascenter.org/u/haohe.umcp)\ **Replies:** 2\ **Last updated:** [October 7, 2024, 2:48am UTC](https://forum.cmascenter.org/t/ioapi-3-2-compiling-error/5270 "2024-10-07T02:48:34Z")
Our supercomputer has updated the OS with the gcc 11.3.0. I tried to recompile the IOAPI\_3.2 to support CMAQ compiling, but met the following error. It didn’t show this format problem when using the old version of gcc 9.… --- ## [NetCDF library conflicts](https://forum.cmascenter.org/t/netcdf-library-conflicts/5262)
**Author:** [@flyenz0](https://forum.cmascenter.org/u/flyenz0)\ **Replies:** 1\ **Last updated:** [October 2, 2024, 4:13pm UTC](https://forum.cmascenter.org/t/netcdf-library-conflicts/5262 "2024-10-02T16:13:39Z")
Probably shot myself in the foot when I tried the apt-install method to install NetCDF that didn’t work as I wasn’t sure what I was doing. I then followed the recommended method by sequentially installing zlib, hdf5, ne… --- ## [Netcdf-fortran compile errors](https://forum.cmascenter.org/t/netcdf-fortran-compile-errors/5250)
**Author:** [@flyenz0](https://forum.cmascenter.org/u/flyenz0)\ **Replies:** 5\ **Last updated:** [October 2, 2024, 2:33pm UTC](https://forum.cmascenter.org/t/netcdf-fortran-compile-errors/5250 "2024-10-02T14:33:09Z")
There are a few discussions involving netcdf installations so I though I’d ask for help here. My CAMx work is waiting on a successful install of netcdf, and I’ve gotten through all but the last step which is the netcdf-f… --- ## [Erro compiling IOAPI 3.2 with PGI compiler](https://forum.cmascenter.org/t/erro-compiling-ioapi-3-2-with-pgi-compiler/5256)
**Author:** [@Autumn](https://forum.cmascenter.org/u/Autumn)\ **Replies:** 0\ **Last updated:** [September 27, 2024, 1:45pm UTC](https://forum.cmascenter.org/t/erro-compiling-ioapi-3-2-with-pgi-compiler/5256 "2024-09-27T13:45:53Z")
Hello, I was trying to install ioapi-3.2 through PGI compiler, Here’s the command: sudo apt-get install libnetcdf-dev cd /home/qiu/Document/Netcdf\_ku git clone GitHub - cjcoats/ioapi-3.2: I/O API Version 3.2: new, be… --- ## [I/O API installation with apple M1](https://forum.cmascenter.org/t/i-o-api-installation-with-apple-m1/5215)
**Author:** [@awelch1](https://forum.cmascenter.org/u/awelch1)\ **Replies:** 6\ **Last updated:** [September 13, 2024, 5:32pm UTC](https://forum.cmascenter.org/t/i-o-api-installation-with-apple-m1/5215 "2024-09-13T17:32:06Z")
Hello everyone, Disclaimer: I am completely inexperienced when it comes to software. I am trying to install I/O API on my M1 mac, but I just can’t seem to compile it successfully. I have tried in the regular zsh and in… --- ## [MTXBUILD run error](https://forum.cmascenter.org/t/mtxbuild-run-error/2506)
**Author:** [@pengzimu](https://forum.cmascenter.org/u/pengzimu)\ **Replies:** 5\ **Last updated:** [July 6, 2023, 4:08pm UTC](https://forum.cmascenter.org/t/mtxbuild-run-error/2506 "2023-07-06T16:08:35Z")
Hi, I met an error when running MTXBUILD to build an I/O API sparse-matrix output file for the transform matrix. The log is shown below: This program uses the EPA-AREAL/MCNC-EnvPgms/BAMS Models-3 I/O Applicatio… --- ## [M3tools writing to existing file](https://forum.cmascenter.org/t/m3tools-writing-to-existing-file/5138)
**Author:** [@gpara35](https://forum.cmascenter.org/u/gpara35)\ **Replies:** 1\ **Last updated:** [August 7, 2024, 11:45am UTC](https://forum.cmascenter.org/t/m3tools-writing-to-existing-file/5138 "2024-08-07T11:45:20Z")
I have a slightly awkward problem I’m trying to solve using m3tools. I’m currently trying to create an MSOILOUT file using an existing BSOILOUT file and a METCRO2D file. The MSOILOUT file needs all of the variables from … --- ## [Ioapi3.2 install #error "Error compiling: unsupported architecture"](https://forum.cmascenter.org/t/ioapi3-2-install-error-error-compiling-unsupported-architecture/5131)
**Author:** [@zhuxiaorui](https://forum.cmascenter.org/u/zhuxiaorui)\ **Replies:** 1\ **Last updated:** [August 6, 2024, 11:33am UTC](https://forum.cmascenter.org/t/ioapi3-2-install-error-error-compiling-unsupported-architecture/5131 "2024-08-06T11:33:19Z")
if \[ ! -d /home/CAMx\_V7.20/tools/ioapi-3.2/Linux2\_x86\_64gfort \]; then mkdir -p /home/CAMx\_V7.20/tools/ioapi-3.2/Linux2\_x86\_64gfort; fi cd /home/CAMx\_V7.20/tools/ioapi-3.2/Linux2\_x86\_64gfort; gcc -c -O3 -ffast-math -fu… --- ## [Errors compiling m3tools](https://forum.cmascenter.org/t/errors-compiling-m3tools/5051)
**Author:** [@gmichals](https://forum.cmascenter.org/u/gmichals)\ **Replies:** 6\ **Last updated:** [July 3, 2024, 12:56pm UTC](https://forum.cmascenter.org/t/errors-compiling-m3tools/5051 "2024-07-03T12:56:55Z")
Trying to compile ioapi3.2 on cluster running two 64-core AMD Epyc “Milan” processors. Im using Intel compiler and admin. installed netCDF C and netCDF fortran also compiled with intel (and curl and MPI) with netCDF4. Fo… --- ## [How to compile IOAPI and CMAQ with cray compilers (ftn/cc/CC)](https://forum.cmascenter.org/t/how-to-compile-ioapi-and-cmaq-with-cray-compilers-ftn-cc-cc/5045)
**Author:** [@Hungnt](https://forum.cmascenter.org/u/Hungnt)\ **Replies:** 1\ **Last updated:** [July 2, 2024, 10:57am UTC](https://forum.cmascenter.org/t/how-to-compile-ioapi-and-cmaq-with-cray-compilers-ftn-cc-cc/5045 "2024-07-02T10:57:38Z")
Dear CMAQ developers and users, I am trying to compile the IOAPI-3.2 library and CMAQv5.4 model with cray compilers (ftn/cc/CC). I have experience with compiling IOAPI and CMAQ with PGI and Intel compilers before but I … --- ## [Error in compiling glibc-2.14](https://forum.cmascenter.org/t/error-in-compiling-glibc-2-14/5044)
**Author:** [@Sunchanglei](https://forum.cmascenter.org/u/Sunchanglei)\ **Replies:** 1\ **Last updated:** [July 1, 2024, 12:11pm UTC](https://forum.cmascenter.org/t/error-in-compiling-glibc-2-14/5044 "2024-07-01T12:11:40Z")
Hi all, When I run the nctox test case in SMOKE, I get an error:/disk1/scl/SMOKEv481/subsys/smoke/Linux2 x86 64ifort/smkinven: /lib64/libc.so.6:Version’GLIBC 2.14’not found. So I am trying to install version 2.14 of gl… --- ## [Error while running MEGAN3.1 test case](https://forum.cmascenter.org/t/error-while-running-megan3-1-test-case/1322)
**Author:** [@nsanzine](https://forum.cmascenter.org/u/nsanzine)\ **Replies:** 2\ **Last updated:** [February 24, 2020, 8:36pm UTC](https://forum.cmascenter.org/t/error-while-running-megan3-1-test-case/1322 "2020-02-24T20:36:00Z")
I am trying to run the test case for MEGAN and I get the following error when I run a program that converts text files into an ioapi format: This program uses the EPA-AREAL/MCNC-EnvPgms/BAMS Models-3 I/O Applications … --- ## [Make\[1\]: Leaving directory .../ioapi-3.2/m3tools](https://forum.cmascenter.org/t/make-1-leaving-directory-ioapi-3-2-m3tools/4977)
**Author:** [@mahsasoleimani](https://forum.cmascenter.org/u/mahsasoleimani)\ **Replies:** 2\ **Last updated:** [June 6, 2024, 9:40pm UTC](https://forum.cmascenter.org/t/make-1-leaving-directory-ioapi-3-2-m3tools/4977 "2024-06-06T21:40:23Z")
Hi everyone, I am compiling IOAPI, following the instructions on Home · CEMPD/SMOKE Wiki · GitHub, and have successfully installed the required packages. At the final stage of ioapi compilation, when running ./compile.i… --- ## [M3cple behaviour in regriding](https://forum.cmascenter.org/t/m3cple-behaviour-in-regriding/4770)
**Author:** [@ardastan](https://forum.cmascenter.org/u/ardastan)\ **Replies:** 3\ **Last updated:** [March 25, 2024, 7:18pm UTC](https://forum.cmascenter.org/t/m3cple-behaviour-in-regriding/4770 "2024-03-25T19:18:30Z")
Hi As per the recommendation of @cjcoats in here, I tried m3cple from the m3tools to regrid data from a large domain with coarse grid (36 km) to a smaller one with fine cells (1.8 km). The projection systems of both gri… --- ## [M3fake run error](https://forum.cmascenter.org/t/m3fake-run-error/4756)
**Author:** [@lwu127](https://forum.cmascenter.org/u/lwu127)\ **Replies:** 1\ **Last updated:** [March 6, 2024, 7:45pm UTC](https://forum.cmascenter.org/t/m3fake-run-error/4756 "2024-03-06T19:45:20Z")
Hi everyone, I am trying to use m3fake tool to convert csv file to IOAPI format. I chose “Input from user-specified file”. I wonder what format should i follow to write the csv file. I read the instructions on the m3fak… --- ## [Error while time-shifting NHEMI\_201906c file](https://forum.cmascenter.org/t/error-while-time-shifting-nhemi-201906c-file/4659)
**Author:** [@afernandez](https://forum.cmascenter.org/u/afernandez)\ **Replies:** 5\ **Last updated:** [January 26, 2024, 1:33pm UTC](https://forum.cmascenter.org/t/error-while-time-shifting-nhemi-201906c-file/4659 "2024-01-26T13:33:08Z")
Hello, Trying to time-shift CCTM\_CONC\_v532\_intel18.0\_CMAQv53\_TS\_108NHEMI\_201906\_dailyav.nc is generating the following output/error: $ ./run\_tshift.sh This program uses the EPA-AREAL/MCNC-EnvPgms/BAMS Models-3 I/O … --- ## [When I compile ioapi, I cannot perform the make configure operation. When I enter make, I use Tab to complete, but various compilation options including configure, install, all, clean, etc. cannot be displayed. But you can do this step on other servers](https://forum.cmascenter.org/t/when-i-compile-ioapi-i-cannot-perform-the-make-configure-operation-when-i-enter-make-i-use-tab-to-complete-but-various-compilation-options-including-configure-install-all-clean-etc-cannot-be-displayed-but-you-can-do-this-step-on-other-servers/4493)
**Author:** [@yaozehui](https://forum.cmascenter.org/u/yaozehui)\ **Replies:** 1\ **Last updated:** [October 18, 2023, 12:03pm UTC](https://forum.cmascenter.org/t/when-i-compile-ioapi-i-cannot-perform-the-make-configure-operation-when-i-enter-make-i-use-tab-to-complete-but-various-compilation-options-including-configure-install-all-clean-etc-cannot-be-displayed-but-you-can-do-this-step-on-other-servers/4493 "2023-10-18T12:03:42Z")
--- ## [Regrid mcip outputs](https://forum.cmascenter.org/t/regrid-mcip-outputs/4260)
**Author:** [@kiarash\_farzad](https://forum.cmascenter.org/u/kiarash_farzad)\ **Replies:** 4\ **Last updated:** [October 6, 2023, 1:14am UTC](https://forum.cmascenter.org/t/regrid-mcip-outputs/4260 "2023-10-06T01:14:10Z")
Hi, I have been trying to regrid my mcip and emission files recently to produce files for my d02. My d01 is at 12km and d02 is at 3km. I was able to use a mixture of M3WNDW and M3CPLE to achieve what I needed to some ex… --- ## [Cannot build m3tools with mpi support; get super long error](https://forum.cmascenter.org/t/cannot-build-m3tools-with-mpi-support-get-super-long-error/4454)
**Author:** [@HectorVG](https://forum.cmascenter.org/u/HectorVG)\ **Replies:** 2\ **Last updated:** [October 4, 2023, 5:47pm UTC](https://forum.cmascenter.org/t/cannot-build-m3tools-with-mpi-support-get-super-long-error/4454 "2023-10-04T17:47:37Z")
I have successfully built both I/O API and m3tools without PnetCDF/MPI support (using Makeinclude.Linux2\_x86\_64gfort and Makefile.nocpl). However, to my understanding (please correct me if I’m wrong), I also need to buil… --- ## [Erro compiling IOAPI 3.2 with intel 23.2.1](https://forum.cmascenter.org/t/erro-compiling-ioapi-3-2-with-intel-23-2-1/4375)
**Author:** [@rpedruzzi](https://forum.cmascenter.org/u/rpedruzzi)\ **Replies:** 6\ **Last updated:** [September 20, 2023, 11:45am UTC](https://forum.cmascenter.org/t/erro-compiling-ioapi-3-2-with-intel-23-2-1/4375 "2023-09-20T11:45:44Z")
Dear colleges, I am trying to compile I/O API 3.2 with intel compiler v2023.2.1 (CC=icc), netcdf 4.7.4 classic, with nocpl, and I am facing the following error: cd /opt/ohpc/pub/apps/libs/ioapi/ioapi-3.2/Linux2\_x86\_64if… --- ## [Re-grid (Aggregate & Re-project) Custom Emission Files](https://forum.cmascenter.org/t/re-grid-aggregate-re-project-custom-emission-files/4219)
**Author:** [@kiarash\_farzad](https://forum.cmascenter.org/u/kiarash_farzad)\ **Replies:** 2\ **Last updated:** [August 14, 2023, 3:22pm UTC](https://forum.cmascenter.org/t/re-grid-aggregate-re-project-custom-emission-files/4219 "2023-08-14T15:22:31Z")
Hi, I was wondering how I can aggregate and re-project my ioapi netcdf emission files? I would appreciate any possible solutions. I tried using INSERTGRID from IOAPI m3tools to make it happen, and I am facing the follo… --- ## [M3Tools Error - Airs2m3](https://forum.cmascenter.org/t/m3tools-error-airs2m3/4275)
**Author:** [@nvs28](https://forum.cmascenter.org/u/nvs28)\ **Replies:** 7\ **Last updated:** [July 31, 2023, 4:11pm UTC](https://forum.cmascenter.org/t/m3tools-error-airs2m3/4275 "2023-07-31T16:11:13Z")
Hi, I am getting the following error while trying to compile ioapi and m3tools using ifort and netcdf. Netcdf was compiled with --disable-netcdf4 --disable-dap. I have also updated Archflags with DIOAPI\_NCF4=1. The err… --- ## [\[airs2m3\] Error](https://forum.cmascenter.org/t/airs2m3-error/2544)
**Author:** [@xiangyu](https://forum.cmascenter.org/u/xiangyu)\ **Replies:** 5\ **Last updated:** [July 5, 2023, 3:19pm UTC](https://forum.cmascenter.org/t/airs2m3-error/2544 "2023-07-05T15:19:01Z")
Hello, I was trying to install ioapi-3.2 through intel compiler, but keep getting the following error message: “…/CMAQv5.3.2/src/ioapi-3.2/Linux2\_x86\_64ifort/libnetcdff.a(nf\_var1io.o): In function nf\_put\_var1\_int64\_': … [Next page](https://forum.cmascenter.org/c/ioapi/5.md?page=1)