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semimajor = 6377340.189,
semiminor = 6356034.447,
ecc = 0.006670540293336110419293763349975612794125,
n1 = local n1ir=0.001673220384152058651484728058385228837777 ,▼
scale = 1.000035,
e0 = 200000.0,
n0 = 250000.0,
lat0 = 53.5,
lon0 = -8.0
}
local function IrishEN2LL(e,n)
local e2irlatlong = EN2LL(e,n,IEglobe .ecc)▼ -- True Origin is 8 deg W
local phi0ir=-8.0
-- True Origin is 53.5 deg N
local lambda0ir=53.5
-- scale factor @ central meridian
local F0ir=1.000035
-- True origin in 200 km E of false origin
local E0ir=200000.0
--True origin is 250km N of false origin
local N0ir=250000.0
-- semi-major axis (in line to equator) 1.000035 is yer scale @ central meridian
local air=IEglobe.semimajor*F0ir
--semi-minor axis (in line to poles)
local bir=IEglobe.semiminor*F0ir
-- flatness=a1-b1/(a1 + b1)
▲ local n1ir=0.001673220384152058651484728058385228837777
-- first eccentricity squared=2*f-f^2 where f=(a1-b1)/a1
local k=(n-N0ir)/air+lambda0ir/dr
local nextcounter=0
local j3,j4,j5,j6,m
repeat
nextcounter=nextcounter+1
local k3=k-lambda0ir/dr
local k4=k+lambda0ir/dr
j3=(1.0+n1ir+1.25*pow(n1ir,2.0)+1.25*pow(n1ir,3.0))*k3
j4=(3.0*n1ir+3.0*pow(n1ir,2.0)+2.625*pow(n1ir,3.0))*sin(k3)*cos(k4)
j5=(1.875*pow(n1ir,2.0)+1.875*pow(n1ir,3.0))*sin(2.0*k3)*cos(2.0*k4)
j6=35.0/24.0*pow(n1ir,3.0)*sin(3.0*k3)*cos(3.0*k4)
m=bir*(j3-j4+j5-j6)
k=k+(n-N0ir-m)/air
until abs(n-N0ir-m)<=0.000000000001 or nextcounter>=10000
local v=air/sqrt(1.0-e2ir*pow(sin(k),2.0))
local r=v*(1.0-e2ir)/(1.0-e2ir*pow(sin(k),2.0))
local h2=v/r-1.0
local y1=e-E0ir
j3=tan(k)/(2.0*r*v)
j4=tan(k)/(24.0*r*pow(v,3.0))*(5.0+3.0*pow(tan(k),2.0)+h2-9.0*pow(tan(k),2.0)*h2)
j5=tan(k)/(720.0*r*pow(v,5.0))*(61.0+90.0*pow(tan(k),2.0)+45.0*pow(tan(k),4.0))
local k9=k-y1*y1*j3+pow(y1,4.0)*j4-pow(y1,6.0)*j5
j6=1.0/(cos(k)*v)
local j7=1.0/(cos(k)*6.0*pow(v,3.0))*(v/r+2.0*pow(tan(k),2.0))
local j8=1.0/(cos(k)*120.0*pow(v,5.0))*(5.0+28.0*pow(tan(k),2.0)+24.0*pow(tan(k),4.0))
local j9=1.0/(cos(k)*5040.0*pow(v,7.0))
local j9=j9*(61.0+662.0*pow(tan(k),2.0)+1320.0*pow(tan(k),4.0)+720.0*pow(tan(k),6.0))
local long=phi0ir+dr*(y1*j6-y1*y1*y1*j7+pow(y1,5.0)*j8-pow(y1,7.0)*j9)
local lat=k9*dr
local helmert = HelmertDatumShift ( lat, long, IE2WGSparam)
return {region="IE",lat=helmert.lat,long=helmert.lon}
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