Convert data values in columns to another value based on a math formula

Question

ISSUE:
I have a database of emergency incidents with descriptive data and longitude and
latitude. I would like to make a google map out of the information but unfortunately
the X Y coordinates are projected in Florida State Plane West in feet. Google maps
requires WGS84 longitude and latitude in decimal degrees.
PROBLEM:
I have written some code in Transact SQL that will convert the values. But I am at a loss as to how to do the following:
1.) plug in the X Y values from my database using an sql SELECT statement.
2.) apply the formula to convert from State Plane to WGS84 to these X Y values
3.) output the results.
In other words, I have the data and I have the formula, but I am not figuring out how to plug the data into the formula and output the results. I am missing how to tie it all together.
CODE:
DECLARE @Easting DECIMAL(18,10);
--SET @Easting = CAST(I_MapX AS DECIMAL(18,10));
DECLARE @Northing DECIMAL(18,10);
--SET @Northing = CAST(I_MapY AS DECIMAL(18,10));
DECLARE @m2sft DECIMAL(10,10);
SET @m2sft = 1200.0/3937.0;
DECLARE @N0 DECIMAL(3,2);
SET @N0 = 0.0;
DECLARE @E0 DECIMAL(18,11);
SET @E0 = 656166.6666666665;
DECLARE @S0 DECIMAL(12,5);
SET @S0 = 2692050.5001/@m2sft;
DECLARE @K0 DECIMAL(18,18);
SET @K0 = 0.9999411764705882;
DECLARE @a DECIMAL(10,2);
SET @a = 6378137.0/@m2sft;
DECLARE @e DECIMAL(18,17);
SET @e = 0.0818191911198883;
DECLARE @ePrime DECIMAL(18,17);
SET @ePrime = 0.08208852110265381;
DECLARE @r DECIMAL(18,10);
SET @r = 6367449.14577/@m2sft;
DECLARE @V0 DECIMAL(15,12);
SET @V0 = 0.005022893948;
DECLARE @V2 DECIMAL(15,12);
SET @V2 = 0.000029370625;
DECLARE @V4 DECIMAL(15,12);
SET @V4 = 0.000000235059;
DECLARE @V6 DECIMAL(15,12);
SET @V6 = 0.000000002181;
DECLARE @L0 DECIMAL(4,2);
SET @L0 = 82.0;
DECLARE @w DECIMAL(18,10);
SET @w = (@Northing - @N0 + @S0)/(@k0*@r);
DECLARE @of DECIMAL(18,10);
SET @of = @w + (sin(@w)*cos(@w))*(@V0 + @V2*power(cos(@w),2) + @V4*power(cos(@w),4) + @V6*power(cos(@w),6));
DECLARE @Rf DECIMAL(18,10);
SET @Rf = @k0*@a/sqrt((1 - power(@e,2)*power(sin(@of),2)));
DECLARE @EPrime2 DECIMAL(18,10);
SET @EPrime2 = @Easting - @E0;
DECLARE @Q DECIMAL(18,10);
SET @Q = @EPrime2/@Rf;
DECLARE @tf DECIMAL(18,10);
SET @tf = tan(@of);
DECLARE @nf DECIMAL(18,10);
SET @nf = @ePrime*cos(@of);
DECLARE @B2 DECIMAL(18,10);
SET @B2 = -0.5 * @tf * (1 + POWER(@nf,2));
DECLARE @B4 DECIMAL(18,10);
SET @B4 = -1/12*(5 + 3 * POWER(@tf,2) +POWER(@nf,2) * (1-9 * POWER(@tf,2)) - 4 * POWER(@nf,4));
DECLARE @B6 DECIMAL(18,10);
SET @B6 = 1/360*(61 + 90*POWER(@tf,2) + 45*POWER(@tf,4) + POWER(@nf,2)*(46 - 252*POWER(@tf,2) - 90*POWER(@tf,4)));
DECLARE @Latitude DECIMAL(18,10);
SET @Latitude = (@of + @B2*POWER(@Q,2)*(1 + POWER(@Q,2)*(@B4 + @B6*POWER(@Q,2))))*180/(PI());
DECLARE @B3 DECIMAL(18,10);
SET @B3 = -1/6*(1 + 2*POWER(@tf,2) + POWER(@nf,2));
DECLARE @B5 DECIMAL(18,10);
SET @B5 = 1/120*(5 + 28*POWER(@tf,2) + 24*POWER(@tf,4) + POWER(@nf,2)*(6 + 8*POWER(@tf,2)));
DECLARE @B7 DECIMAL(18,10);
SET @B7 = -1/5040*(61 + 662*POWER(@tf,2) + 1320*POWER(@tf,4) + 720*POWER(@tf,6));
DECLARE @L DECIMAL(18,10);
SET @L = @Q*(1 + POWER(@Q,2)*(@B3 + POWER(@Q,2)*(@B5 + @B7*POWER(@Q,2))));
DECLARE @Longitude DECIMAL(18,10);
SET @Longitude = (@L0 - (@L/cos(@of))*180/(PI()))*-1;
SELECT
I_EventNumber
FROM Incident
WHERE I_tTimeDispatch > 'May 7, 2012'
SAMPLE DATA:
Here is some raw data in order to get you started. Please notice the MapX and MapY
coordinates are VARCHAR because they are Florida State Plane projections. The goal is
to take these and turn them into WGS84 longitude and latitude expressed as decimal
degrees to be used in Google maps. NOTE: I can convert from VARCHAR to DECIMAL. I just can't figure out where to plug my database columns into the sql query to output a result.
CREATE TABLE Incidents
I_EventNumber VARCHAR(20)
I_MapY VARCHAR(15)
I_MapX VARCHAR(15)
INSERT INTO Incident
VALUES
(FCW69, 0815312, 0672298)
, (FCW70, 0833311, 0697870)
, (FCW71, 0807747, 0699684)
, (FCW72, 0801252, 0689469)
, (FCW73, 0853491, 0692350)

Answer 1

Here's a way to get the results, all as part of a single extensive query (this would probably be more suited for defining a VIEW, where you could join on the input table with the VIEW to incorporate the computed values.
If you instead had a business situation where you might need to execute this logic from many different places, rewriting as a user defined function might be better.  Anyway, for the answer plus a demonstration of the power of CROSS APPLY to generate
interim working values...
Create_Sample_Data:
Declare @Incident TABLE
I_EventNumber VARCHAR(20), I_MapY VARCHAR(15), I_MapX VARCHAR(15)
INSERT INTO @Incident
VALUES
('FCW69', '0815312', '0672298')
, ('FCW70', '0833311', '0697870')
, ('FCW71', '0807747', '0699684')
, ('FCW72', '0801252', '0689469')
, ('FCW73', '0853491', '0692350') /* This insert is SQL 2008 syntax only.. do multiple inserts or a UNION for 2005 */
AsQuery:
Select *
from @INCIDENT
Cross Apply
Select
N0 = 0.0,
E0 = 656166.6666666665,
K0 = 0.9999411764705882,
e = 0.0818191911198883,
ePrime = 0.08208852110265381,
V0 = 0.005022893948,
V2 = 0.000029370625,
V4 = 0.000000235059,
V6 = 0.000000002181,
L0 = 82.0,
Easting = CAST(I_MapX AS DECIMAL(18,10)),
Northing = CAST(I_MapY AS DECIMAL(18,10))
) as CAStatic
Cross Apply
Select m2sft = 1200.0/3937.0,
EPrime2 = Easting - E0
) as CAComputed1
Cross Apply
Select S0 = 2692050.5001/m2sft,
r = 6367449.14577/m2sft,
a = 6378137.0/m2sft
) as CAComputed2
Cross Apply
Select
w = (Northing - N0 + S0)/(k0*r)
) as CAComputed4
Cross Apply
Select
[of] = w + (sin(w)*cos(w))*(V0 + V2*power(cos(w),2) + V4*power(cos(w),4) + V6*power(cos(w),6))
) as CAComputed5
Cross Apply
Select
Rf = k0*a/sqrt((1 - power(e,2)*power(sin([of]),2))),
tf = tan([of]),
nf = ePrime*cos([of])
) as CAComputed6
Cross Apply
Select
Q = EPrime2/Rf,
B2 = -0.5 * tf * (1 + POWER(nf,2)),
B4 = -1/12*(5 + 3 * POWER(tf,2) +POWER(nf,2) * (1-9 * POWER(tf,2)) - 4 * POWER(nf,4)),
B6 = 1/360*(61 + 90*POWER(tf,2) + 45*POWER(tf,4) + POWER(nf,2)*(46 - 252*POWER(tf,2) - 90*POWER(tf,4)))
) as CAComputed7
Cross Apply
Select
Latitude = ([of] + B2*POWER(Q,2)*(1 + POWER(Q,2)*(B4 + B6*POWER(Q,2))))*180/(PI()),
B3 = -1/6*(1 + 2*POWER(tf,2) + POWER(nf,2)),
B5 = 1/120*(5 + 28*POWER(tf,2) + 24*POWER(tf,4) + POWER(nf,2)*(6 + 8*POWER(tf,2))),
B7 = -1/5040*(61 + 662*POWER(tf,2) + 1320*POWER(tf,4) + 720*POWER(tf,6))
) as CAComputed8
Cross Apply
Select
L = Q*(1 + POWER(Q,2)*(B3 + POWER(Q,2)*(B5 + B7*POWER(Q,2))))
) as CAComputed9
Cross Apply
Select
Longitude = (L0 - (L/cos([of]))*180/(PI()))*-1
) as CAComputedLatLong
Notice that each subsequent CROSS APPLY depends on a "working value" column being defined in some previous cross apply, or the working query.  There are a few other options, such as leaving off the very last Cross Apply, and computing Longitude as part
of the main query at the beginning, but it works either way.
EDIT: P.S. - By the way, this query is based on the formula in the original poster's query.  My formula matches that formula, and I bet it's right (as far as the lat/long conversion), but it could be the formula for Soylent Green, and I wouldn't know any
better... :-)