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I am trying to convert a set of lat long to state plane coordinates using python and pyproj. The location is Tennessee and this gave me information about the central meridian, lat origin and the proj type which are 35.2500,34.333 and lambert conformal conic respectively. When i use National Geodetic survey's tool to do the conversion for a sample long lat(-86.911,36.316), i get this result:

NORTH(Y) EAST(X) AREA

220358.963 518192.337 TN

When i try doing this by code, the results are different:
Here is the piece of code:

from pyproj import Proj

p = Proj(proj='lcc',zone=4100,lon_0='35.35w',lat_1='34.33n')
x,y = p(-86.911,36.316)
print x
print y

Result x,y is: -4367838.06379 5640715.01601

I cannot understand where i am going wrong. Please advice.

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From what I understand (not tested) 35.35 and 34.33 are the coordinates of the parallels (lat_1 and lat_2). The central meridian (lon_0) is -86. Also you might have a false easting of 600 000

As a remark, I've found (on spatialrefeence.org) the below definition for projection in Tennessee, which is slightly different from yours, but could help you fill your parameters :

+proj=lcc +lat_1=35.25 +lat_2=36.41666666666666 +lat_0=34.66666666666666 +lon_0=-86 +x_0=609601.2192024384 +y_0=30480.06096012192 +ellps=clrk66 +datum=NAD27 +to_meter=0.3048006096012192 +no_defs

or for NAD83

+proj=lcc +lat_1=37.93333333333333 +lat_2=36.73333333333333 +lat_0=36.33333333333334 +lon_0=-85.75 +x_0=500000.0001016001 +y_0=500000.0001016001 +ellps=GRS80 +datum=NAD83 +to_meter=0.3048006096012192 +no_defs

Note that the coordinates are in feet.

  • right. I went to spatialreference.org as well and found the parameters. however, i still get a difference between the ones that i get now and the one that i get from NGS's tool. – statBeginner Nov 7 '14 at 21:07
  • sorry, I can't check now. But above I gave the parameter for the NAD27-based projection. Maybe your params are from the NAD83 – radouxju Nov 7 '14 at 21:21
  • The parameters would depend on what is the exact implementation but the solution is to use all the parameters as suggested in the answer and refer to spatialreference.org. Hence marking as accepted answer. – statBeginner Nov 8 '14 at 6:08

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