Replace Numerial Recipes LU-decomp routines with LAPACK ones

.github/workflows/Linux.yml

@@ -33,6 +33,7 @@ jobs:
 
     - name: build
       run: |
+        sudo apt install libopenblas-dev
         cd ip
         mkdir build 
         cd build

.github/workflows/MacOS.yml

@@ -32,6 +32,7 @@ jobs:
 
     - name: build
       run: |
+        brew install openblas
         cd ip
         mkdir build 
         cd build

.github/workflows/Spack.yml

@@ -33,6 +33,7 @@ jobs:
 
     - name: spack-build-and-test
       run: |
+        sudo apt install libopenblas-dev
         git clone -c feature.manyFiles=true https://github.com/spack/spack
         . spack/share/spack/setup-env.sh
         spack env create ip-env
@@ -42,7 +43,7 @@ jobs:
         spack add ip@develop%gcc@11 ${{ matrix.variants }} target=x86_64
         precision=$(echo ${{ matrix.variants }} | grep -oP " precision=\K[4d8]")
         if [ "$precision" == "d" ]; then spack add grib-util@develop ; fi
-        spack external find cmake gmake
+        spack external find cmake gmake openblas
         spack concretize
         # Run installation and run CTest suite
         spack install --verbose --fail-fast --test root

.github/workflows/developer.yml

@@ -25,7 +25,7 @@ jobs:
     - name: Install Dependencies
       run: |
         sudo apt-get update
-        sudo apt-get install doxygen
+        sudo apt-get install doxygen libopenblas-dev
         python3 -m pip install gcovr
 
     - name: checkout

CMakeLists.txt

@@ -48,6 +48,10 @@ endif()
 if(OPENMP)
   find_package(OpenMP REQUIRED COMPONENTS Fortran)
 endif()
+if(CMAKE_Fortran_COMPILER_ID MATCHES "^(Intel|IntelLLVM)$")
+  set(BLA_VENDOR Intel10_64lp)
+endif()
+find_package(LAPACK)
 
 # Set compiler flags.
 if(CMAKE_Fortran_COMPILER_ID MATCHES "^(Intel|IntelLLVM)$")

spack/package.py

@@ -65,6 +65,7 @@ class Ip(CMakePackage):
     depends_on("sp precision=4", when="@4.1:4 precision=4")
     depends_on("sp precision=d", when="@4.1:4 precision=d")
     depends_on("sp precision=8", when="@4.1:4 precision=8")
+    depends_on("lapack", when="@develop")
 
     def cmake_args(self):
         args = [

src/CMakeLists.txt

@@ -77,6 +77,7 @@ foreach(kind ${kinds})
   if(OpenMP_Fortran_FOUND)
     target_link_libraries(${lib_name} PUBLIC OpenMP::OpenMP_Fortran)
   endif()
+  target_link_libraries(${lib_name} PUBLIC LAPACK::LAPACK)
 
   list(APPEND LIB_TARGETS ${lib_name})
 

src/splat.F

@@ -64,7 +64,7 @@ SUBROUTINE SPLAT(IDRT,JMAX,SLAT,WLAT)
      $ 146.870307625, 150.011882457, 153.153458019, 156.295034268 /
       REAL:: DLT,D1=1.
       REAL AWORK((JMAX+1)/2,((JMAX+1)/2)),BWORK(((JMAX+1)/2))
-      INTEGER:: JHE,JHO,J0=0
+      INTEGER:: JHE,JHO,J0=0, INFO
       INTEGER IPVT((JMAX+1)/2)
       PARAMETER(PI=3.14159265358979,C=(1.-(2./PI)**2)*0.25)
 C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -133,8 +133,14 @@ SUBROUTINE SPLAT(IDRT,JMAX,SLAT,WLAT)
           BWORK(JS)=-D1/(4*(JS-1)**2-1)
         ENDDO
 
-        call ludcmp(awork,jho,jhe,ipvt)
-        call lubksb(awork,jho,jhe,ipvt,bwork)
+        ! Call LAPACK routines
+#if (LSIZE==4)
+        CALL SGETRF(JHO, JHO, AWORK, JHE, IPVT, INFO)
+        CALL SGETRS('N', JHO, 1, AWORK, JHE, IPVT, BWORK, JHO, INFO)
+#else
+        CALL DGETRF(JHO, JHO, AWORK, JHE, IPVT, INFO)
+        CALL DGETRS('N', JHO, 1, AWORK, JHE, IPVT, BWORK, JHO, INFO)
+#endif
 
         WLAT(1)=0.
         DO J=1,JHO
@@ -170,8 +176,14 @@ SUBROUTINE SPLAT(IDRT,JMAX,SLAT,WLAT)
           BWORK(JS)=-D1/(4*(JS-1)**2-1)
         ENDDO
 
-        call ludcmp(awork,jho,jhe,ipvt,d)
-        call lubksb(awork,jho,jhe,ipvt,bwork)
+        ! Call LAPACK routines
+#if (LSIZE==4)
+        CALL SGETRF(JHO, JHO, AWORK, JHE, IPVT, INFO)
+        CALL SGETRS('N', JHO, 1, AWORK, JHE, IPVT, BWORK, JHO, INFO)
+#else
+        CALL DGETRF(JHO, JHO, AWORK, JHE, IPVT, INFO)
+        CALL DGETRS('N', JHO, 1, AWORK, JHE, IPVT, BWORK, JHO, INFO)
+#endif
 
         WLAT(1)=0.
         DO J=1,JHO