id summary reporter owner description type status priority milestone component version resolution keywords cc 959 Important: Upated CMEPS NUOPC cap module arango "I implemented the changes made by Ufuk Turunçoğlu to **cmeps_roms.F**, now called **cmeps_roms.h**, to avoid interference with the native framework. The native **ROMS** NUOPC ''cap'' module is now called **esmf_roms.h**. Either NUOPC module is included in **esmf_roms.F** via CPP. The coupling interface for **CDEPS/CMEPS** is activated with the **CMEPS** option, and is intended for connecting to the [https://github.com/oceanmodeling/ufs-coastal UFS-coastal] framework. For now, the **UFS-coastal** repository is downloaded from: {{{ git -c submodule.ADCIRC.update=none clone -b feature/coastal_app --recursive https://github.com/oceanmodeling/ufs-coastal }}} Notice that we are omitting the **ADCIRC** component during the cloning since it is still private and working with the research branch **feature/coastal_app**. This coupling capability is still under development and is complex. Thus, it is not ready for the regular user. We are currently testing the interface to connect **ROMS** to the **UFS** coupling framework. An **ESM/build_ufs.sh** is provided to facilitate configuring and compiling any ROMS application. It is currently configured for the Hurricane Irene (**IRENE**) application. See [https://github.com/myroms/roms_test/blob/feature/ufs/IRENE/Coupling/roms_data_cmeps/Readme.md roms_test] for more information. It works for the **ROMS-DATA** coupling system using the **CDEFS** connectors or the **CMEPS** mediator. The **DATA** component is replacing the atmosphere model, and it tests **ROMS** connection to **CDEPS**, **CMEPS**, and **UFS** coupling driver. ---- === [[span(style=color: #0000FF,LAPACK/ARPACK Legacy Library:)]] === The **ARPACK** and its MPI-based parallel (**PARPACK**) version are well-tested libraries to solve large eigenvalue matrix problems. Our primary use in ROMS is to use its Implicit Restarted Arnoldi Method (**IRAM**) to solve for the Ritz eigenfunctions in several of our Tangent and Adjoint-based **propagators** that are part of the Generalized Linear Stability (**GLS**) package described in Moore ''et al.'' (2004) Ocean Modelling paper https://doi.org/10.1016/j.ocemod.2003.11.001. As far as I know, we cannot use a modern replacement library. Therefore, we will continue using that library when running any of the drivers of the **GLS** package. However, the **ARPACK** library includes selected Linear Algebra functions from the **BLAS** and **LAPACK** libraries. In particular, we use **LAPACK**'s **DSTEQR** function to solve for the eigenvalues/eigenvectors of the tri-diagonal system used in the various 4D-Var minimizations available in ROMS. Thus, I spent some time looking for a replacement. It turns out that any modern software out there is built on top of **LAPACK** (Phyton, MATLAB, R, !SciPy, and others). There are also bindings to **C** and **C++**. We could use the **eigen**, written in **C++**, but it will be complicated since I will have to write and test the inter-operability mechanism in ROMS for **C++** to **Fortran 2003** and vice versa (**Fortran 2003** to **C++**). It turns out that the **libeigen** has **BLAS** and **LAPACK** components. See: https://gitlab.com/libeigen/eigen. On top of that, there are reports that the **eigen** library is much slower than Fortran libraries. Thus, I am giving up on the **eigen** library. It is beyond our scope. I decided to adapt the functions we need from **LAPACK** into module **lapack_mod.F**, which I converted to **Fortran 2003**. It includes a total of 19 **LAPACK** functions. I modernized the code, which had initially 41 **GOTO**s. I managed to remove 18 of them. The remaining 23 are located in the function **DSTEQR**. I was able to get identical 4D-Var solutions during testing. That eigenfunction solver is tricky, and removing the remaining **GOTO**s is dangerous. The complicated **GOTO**s are still in selected functions but can be removed from the final C-preprocessing file (**lapack_mod.f90**) by activating the CPP option **REMOVE_LAPACK_GOTOS**. For example, in the function **DLASRT** used to sort the eigenvalues, I have: {{{ #ifdef REMOVE_LAPACK_GOTOS DecLOOP_3 : DO ! forever LOOP 3 DecLOOP_1 : DO ! forever LOOP 1 J = J - 1 IF (D(J) .GE. DMNMX) EXIT DecLOOP_1 ! terminate LOOP 1 END DO DecLOOP_1 ! DecLOOP_2 : DO ! forever LOOP 2 I = I + 1 IF (D(I) .LE. DMNMX) EXIT DecLOOP_2 ! terminate LOOP 2 END DO DecLOOP_2 ! IF (I .LT. J) THEN TMP = D(I) D(I) = D(J) D(J) = TMP CYCLE DecLOOP_3 ! iterate LOOP 3 ELSE EXIT DecLOOP_3 ! terminate LOOP 3 END IF END DO DecLOOP_3 #else 60 CONTINUE 70 CONTINUE J = J - 1 IF (D(J) .LT. DMNMX) GO TO 70 80 CONTINUE I = I + 1 IF (D(I) .GT. DMNMX) GO TO 80 IF (I .LT. J) THEN TMP = D(I) D(I) = D(J) D(J) = TMP GO TO 60 END IF #endif }}} Notice that the above piece of code is slightly complicated. It requires knowledge of the modern Fortran Standard and Objective-Oriented Programming principles to remove the **GOTO**s, which were unavailable in Fortran and compilers over 40 years ago. This doesn't imply that the **LAPACK** library is incorrect and produces the wrong results. I am keeping the original code with the **GOTO**s for reference and testing. [[span(style=color: #FF0000, We no longer need the **LAPACK/ARPACK** libraries to run any 4D-Var drivers in ROMS because the functions that we need are available in our modern adaptation module **lapack_mod.F**)]]. ---- Many thanks to Ufuk Turunçoğlu for his hard work and help connecting **ROMS** to the **UFS-coastal**." upgrade closed major Release ROMS/TOMS 4.2 Nonlinear 4.1 Done