feature/regional_grid This commit references NOAA-EMC#4.

Add new regional_esg_grid code, which is a possible replacement
for the original regional_grid code.  Taken from Dusan's
regional workflow branch.

sorc/fre-nctools.fd/CMakeLists.txt

@@ -6,3 +6,4 @@ add_subdirectory(tools/filter_topo)
 add_subdirectory(tools/shave.fd)
 add_subdirectory(tools/global_equiv_resol.fd)
 add_subdirectory(tools/regional_grid.fd)
+add_subdirectory(tools/regional_esg_grid.fd)

sorc/fre-nctools.fd/tools/regional_esg_grid.fd/CMakeLists.txt

@@ -0,0 +1,20 @@
+set(fortran_src
+    pesg.f90
+    pfun.f90
+    pietc.f90
+    pietc_s.f90
+    pkind.f90
+    pmat.f90
+    pmat2.f90
+    pmat4.f90
+    pmat5.f90
+    psym2.f90
+    regional_esg_grid.f90)
+
+set(exe_name regional_esg_grid)
+add_executable(${exe_name} ${fortran_src})
+target_link_libraries(
+  ${exe_name}
+  NetCDF::NetCDF_Fortran)
+
+install(TARGETS ${exe_name} RUNTIME DESTINATION ${exec_dir})

sorc/fre-nctools.fd/tools/regional_esg_grid.fd/pfun.f90

@@ -0,0 +1,218 @@
+!
+!                                         *********************************
+!                                         *          module pfun          *
+!                                         *          R. J. Purser         *
+!                                         *          NCEP/EMC 2017        *
+!                                         *********************************
+! Direct dependencies:
+! Modules: pkind
+!
+!=============================================================================
+module pfun
+!=============================================================================
+use pkind, only: sp,dp
+implicit none
+private
+public:: gd,gdi,hav,havh,ahav,ahavh,sech,sechs,atanh
+
+interface gd;      module procedure gd_s,    gd_d;     end interface
+interface gdi;     module procedure gdi_s,   gdi_d;    end interface
+interface hav;     module procedure hav_s,   hav_d;    end interface
+interface havh;    module procedure havh_s,  havh_d;   end interface
+interface ahav;    module procedure ahav_s,  ahav_d;   end interface
+interface ahavh;   module procedure ahavh_s, ahavh_d;  end interface
+interface atanh;   module procedure atanh_s, atanh_d;  end interface
+interface sech;    module procedure sech_s,  sech_d;   end interface
+interface sechs;   module procedure sechs_s, sechs_d;  end interface
+
+contains
+
+!=============================================================================
+function gd_s(x) result(y)!                                               [gd]
+!=============================================================================
+! Gudermannian function
+implicit none
+real(sp),intent(in ):: x
+real(sp)            :: y
+y=atan(sinh(x))
+end function gd_s
+!=============================================================================
+function gd_d(x) result(y)!                                               [gd]
+!=============================================================================
+implicit none
+real(dp),intent(in ):: x
+real(dp)            :: y
+y=atan(sinh(x))
+end function gd_d
+
+!=============================================================================
+function gdi_s(y) result(x)!                                             [gdi]
+!=============================================================================
+! Inverse Gudermannian function
+implicit none
+real(sp),intent(in ):: y
+real(sp)            :: x
+x=atanh(sin(y))
+end function gdi_s
+!=============================================================================
+function gdi_d(y) result(x)!                                             [gdi]
+!=============================================================================
+implicit none
+real(dp),intent(in ):: y
+real(dp)            :: x
+x=atanh(sin(y))
+end function gdi_d
+
+!=============================================================================
+function hav_s(t) result(a)!                                             [hav]
+!=============================================================================
+! Haversine function
+use pietc_s, only: o2
+implicit none
+real(sp),intent(in ):: t
+real(sp)            :: a
+a=(sin(t*o2))**2
+end function hav_s
+!=============================================================================
+function hav_d(t) result(a)!                                             [hav]
+!=============================================================================
+use pietc, only: o2
+implicit none
+real(dp),intent(in ):: t
+real(dp)            :: a
+a=(sin(t*o2))**2
+end function hav_d
+
+!=============================================================================
+function havh_s(t) result(a)!                                           [havh]
+!=============================================================================
+! Note the minus sign in the hyperbolic-haversine definition
+use pietc_s, only: o2
+implicit none
+real(sp),intent(in ):: t
+real(sp)            :: a
+a=-(sinh(t*o2))**2
+end function havh_s
+!=============================================================================
+function havh_d(t) result(a)!                                           [havh]
+!=============================================================================
+use pietc, only: o2
+implicit none
+real(dp),intent(in ):: t
+real(dp)            :: a
+a=-(sinh(t*o2))**2
+end function havh_d
+
+!=============================================================================
+function ahav_s(a) result(t)!                                           [ahav]
+!=============================================================================
+use pietc_s, only: u2
+! Arc-haversine function
+implicit none
+real(sp),intent(in ):: a
+real(sp)            :: t
+t=u2*asin(sqrt(a))
+end function ahav_s
+!=============================================================================
+function ahav_d(a) result(t)!                                           [ahav]
+!=============================================================================
+use pietc, only: u2
+implicit none
+real(dp),intent(in ):: a
+real(dp)            :: t
+t=u2*asin(sqrt(a))
+end function ahav_d
+
+!=============================================================================
+function ahavh_s(a) result(t)!                                         [ahavh]
+!=============================================================================
+use pietc_s, only: u2
+! Note the minus sign in the hyperbolic arc-haversine definition
+implicit none
+real(sp),intent(in ):: a
+real(sp)            :: t
+t=u2*asinh(sqrt(-a))
+end function ahavh_s
+!=============================================================================
+function ahavh_d(a) result(t)!                                         [ahavh]
+!=============================================================================
+use pietc, only: u2
+implicit none
+real(dp),intent(in ):: a
+real(dp)            :: t
+t=u2*asinh(sqrt(-a))
+end function ahavh_d
+
+!=============================================================================
+function atanh_s(t) result(a)!                                         [atanh]
+!=============================================================================
+use pietc_s, only: u1,o2,o3,o5
+implicit none
+real(sp),intent(IN ):: t
+real(sp)            :: a,tt
+real(sp),parameter  :: o7=u1/7_sp,o9=u1/9_sp
+!=============================================================================
+if(abs(t)>=u1)stop 'In atanh; no solution'
+if(abs(t)>1.e-3_sp)then; a=log((u1+t)/(u1-t))*o2
+else; tt=t*t;            a=t*(u1+tt*(o3+tt*(o5+tt*(o7+tt*o9))))
+endif
+end function atanh_s
+!=============================================================================
+function atanh_d(t) result(a)!                                         [atanh]
+!=============================================================================
+use pietc, only: u1,o2,o3,o5
+implicit none
+real(dp),intent(IN ):: t
+real(dp)            :: a,tt
+real(dp),parameter  :: o7=u1/7_dp,o9=u1/9_dp
+!=============================================================================
+if(abs(t)>=u1)stop 'In atanh; no solution'
+if(abs(t)>1.e-3_dp)then; a=log((u1+t)/(u1-t))*o2
+else; tt=t*t;            a=t*(u1+tt*(o3+tt*(o5+tt*(o7+tt*o9))))
+endif
+end function atanh_d
+
+!=============================================================================
+function sech_s(x)result(r)!                                            [sech]
+!=============================================================================
+! This indirect way of computing 1/cosh(x) avoids overflows at large x
+use pietc_s, only: u1,u2
+implicit none
+real(sp),intent(in ):: x
+real(sp)            :: r
+real(sp)            :: e,ax
+ax=abs(x)
+e=exp(-ax)
+r=e*u2/(u1+e*e)
+end function sech_s
+!=============================================================================
+function sech_d(x)result(r)!                                            [sech]
+!=============================================================================
+use pietc, only: u1,u2
+implicit none
+real(dp),intent(in ):: x
+real(dp)            :: r
+real(dp)            :: e,ax
+ax=abs(x)
+e=exp(-ax)
+r=e*u2/(u1+e*e)
+end function sech_d
+
+!=============================================================================
+function sechs_s(x)result(r)!                                          [sechs]
+!=============================================================================
+implicit none
+real(sp),intent(in ):: x
+real(sp)            :: r
+r=sech(x)**2
+end function sechs_s
+!=============================================================================
+function sechs_d(x)result(r)!                                          [sechs]
+!=============================================================================
+implicit none
+real(dp),intent(in ):: x
+real(dp)            :: r
+r=sech(x)**2
+end function sechs_d
+
+end module pfun

sorc/fre-nctools.fd/tools/regional_esg_grid.fd/pietc.f90

@@ -0,0 +1,96 @@
+!
+!=============================================================================
+module pietc
+!=============================================================================
+!                           R. J. Purser (jim.purser@noaa.gov) 2014
+! Some of the commonly used constants (pi etc) mainly for double-precision
+! subroutines.
+! ms10 etc are needed to satisfy the some (eg., gnu fortran) compilers'
+! more rigorous standards regarding the way "data" statements are initialized.
+! Zero and the first few units are u0,u1,u2, etc., their reciprocals being,
+! o2,o3 etc and their square roots, r2,r3. Reciprocal roots are or2,or3 etc.
+!=============================================================================
+use pkind, only: dp,dpc
+implicit none
+logical ,parameter:: T=.true.,F=.false. !<- for pain-relief in logical ops
+real(dp),parameter:: &
+     u0=0_dp,u1=1_dp,mu1=-u1,u2=2_dp,mu2=-u2,u3=3_dp,mu3=-u3,u4=4_dp,       &
+     mu4=-u4,u5=5_dp,mu5=-u5,u6=6_dp,mu6=-u6,o2=u1/u2,o3=u1/u3,o4=u1/u4,    &
+     o5=u1/u5,o6=u1/u6,mo2=-o2,mo3=-o3,mo4=-o4,mo5=-o5,mo6=-o6,             &
+     pi =3.1415926535897932384626433832795028841971693993751058209749e0_dp, &
+     pi2=6.2831853071795864769252867665590057683943387987502116419498e0_dp, &
+     pih=1.5707963267948966192313216916397514420985846996875529104874e0_dp, &
+     rpi=1.7724538509055160272981674833411451827975494561223871282138e0_dp, &
+! Important square-roots
+     r2 =1.4142135623730950488016887242096980785696718753769480731766e0_dp, &
+     r3 =1.7320508075688772935274463415058723669428052538103806280558e0_dp, &
+     r5 =2.2360679774997896964091736687312762354406183596115257242708e0_dp, &
+     or2=u1/r2,or3=u1/r3,or5=u1/r5,                                         &
+! Golden number:
+     phi=1.6180339887498948482045868343656381177203091798057628621354e0_dp, &
+! Euler-Mascheroni constant:
+     euler=0.57721566490153286060651209008240243104215933593992359880e0_dp, &
+! Degree to radians; radians to degrees:
+     dtor=pi/180,rtod=180/pi,                                               & 
+! Sines of all main fractions of 90 degrees (down to ninths):
+     s10=.173648177666930348851716626769314796000375677184069387236241e0_dp,&
+     s11=.195090322016128267848284868477022240927691617751954807754502e0_dp,&
+     s13=.222520933956314404288902564496794759466355568764544955311987e0_dp,&
+     s15=.258819045102520762348898837624048328349068901319930513814003e0_dp,&
+     s18=.309016994374947424102293417182819058860154589902881431067724e0_dp,&
+     s20=.342020143325668733044099614682259580763083367514160628465048e0_dp,&
+     s22=.382683432365089771728459984030398866761344562485627041433800e0_dp,&
+     s26=.433883739117558120475768332848358754609990727787459876444547e0_dp,&
+     s30=o2,                                                                &
+     s34=.555570233019602224742830813948532874374937190754804045924153e0_dp,&
+     s36=.587785252292473129168705954639072768597652437643145991072272e0_dp,&
+     s39=.623489801858733530525004884004239810632274730896402105365549e0_dp,&
+     s40=.642787609686539326322643409907263432907559884205681790324977e0_dp,&
+     s45=or2,                                                               &
+     s50=.766044443118978035202392650555416673935832457080395245854045e0_dp,&
+     s51=.781831482468029808708444526674057750232334518708687528980634e0_dp,&
+     s54=.809016994374947424102293417182819058860154589902881431067724e0_dp,&
+     s56=.831469612302545237078788377617905756738560811987249963446124e0_dp,&
+     s60=r3*o2,                                                             &
+     s64=.900968867902419126236102319507445051165919162131857150053562e0_dp,&
+     s68=.923879532511286756128183189396788286822416625863642486115097e0_dp,&
+     s70=.939692620785908384054109277324731469936208134264464633090286e0_dp,&
+     s72=.951056516295153572116439333379382143405698634125750222447305e0_dp,&
+     s75=.965925826289068286749743199728897367633904839008404550402343e0_dp,&
+     s77=.974927912181823607018131682993931217232785800619997437648079e0_dp,&
+     s79=.980785280403230449126182236134239036973933730893336095002916e0_dp,&
+     s80=.984807753012208059366743024589523013670643251719842418790025e0_dp,&
+! ... and their minuses:
+     ms10=-s10,ms11=-s11,ms13=-s13,ms15=-s15,ms18=-s18,ms20=-s20,ms22=-s22,&
+     ms26=-s26,ms30=-s30,ms34=-s34,ms36=-s36,ms39=-s39,ms40=-s40,ms45=-s45,&
+     ms50=-s50,ms51=-s51,ms54=-s54,ms56=-s56,ms60=-s60,ms64=-s64,ms68=-s68,&
+     ms70=-s70,ms72=-s72,ms75=-s75,ms77=-s77,ms79=-s79,ms80=-s80
+
+complex(dpc),parameter:: &
+     c0=(u0,u0),c1=(u1,u0),mc1=-c1,ci=(u0,u1),mci=-ci,cipi=ci*pi,     &
+! Main fractional rotations, as unimodular complex numbers:
+     z000=c1        ,z010=( s80,s10),z011=( s79,s11),z013=( s77,s13),&
+     z015=( s75,s15),z018=( s72,s18),z020=( s70,s20),z022=( s68,s22),&
+     z026=( s64,s26),z030=( s60,s30),z034=( s56,s34),z036=( s54,s36),&
+     z039=( s51,s39),z040=( s50,s40),z045=( s45,s45),z050=( s40,s50),&
+     z051=( s39,s51),z054=( s36,s54),z056=( s34,s56),z060=( s30,s60),&
+     z064=( s26,s64),z068=( s22,s68),z070=( s20,s70),z072=( s18,s72),&
+     z075=( s15,s75),z077=( s13,s77),z079=( s11,s79),z080=( s10,s80),&
+     z090=ci,        z100=(ms10,s80),z101=(ms11,s79),z103=(ms13,s77),&
+     z105=(ms15,s75),z108=(ms18,s72),z110=(ms20,s70),z112=(ms22,s68),&
+     z116=(ms26,s64),z120=(ms30,s60),z124=(ms34,s56),z126=(ms36,s54),&
+     z129=(ms39,s51),z130=(ms40,s50),z135=(ms45,s45),z140=(ms50,s40),&
+     z141=(ms51,s39),z144=(ms54,s36),z146=(ms56,s34),z150=(ms60,s30),&
+     z154=(ms64,s26),z158=(ms68,s22),z160=(ms70,s20),z162=(ms72,s18),&
+     z165=(ms75,s15),z167=(ms77,s13),z169=(ms79,s11),z170=(ms80,s10),&
+     z180=-z000,z190=-z010,z191=-z011,z193=-z013,z195=-z015,z198=-z018,&
+     z200=-z020,z202=-z022,z206=-z026,z210=-z030,z214=-z034,z216=-z036,&
+     z219=-z039,z220=-z040,z225=-z045,z230=-z050,z231=-z051,z234=-z054,&
+     z236=-z056,z240=-z060,z244=-z064,z248=-z068,z250=-z070,z252=-z072,&
+     z255=-z075,z257=-z077,z259=-z079,z260=-z080,z270=-z090,z280=-z100,&
+     z281=-z101,z283=-z103,z285=-z105,z288=-z108,z290=-z110,z292=-z112,&
+     z296=-z116,z300=-z120,z304=-z124,z306=-z126,z309=-z129,z310=-z130,&
+     z315=-z135,z320=-z140,z321=-z141,z324=-z144,z326=-z146,z330=-z150,&
+     z334=-z154,z338=-z158,z340=-z160,z342=-z162,z345=-z165,z347=-z167,&
+     z349=-z169,z350=-z170
+end module pietc