Basemap.pyproj: towgs84

Hi,

it seems that pyproj.Proj does not take into account the “towgs84” optional parameter.
Here is what I simply tried:

from mpl_toolkits.basemap import *
lonref = -3.
latref = 47.

kwproj = dict(proj=“lcc”, a=6378249.2, b=6356515., x_0=600000., y_0=200000.,
lon_0=“2d20’14.025”, lat_0=“46d48’”, lat_1=“45d53’56.108”, lat_2=“47d41’45.652”)
print pyproj.Proj(**kwproj)(lonref, latref)

kwproj.update(towgs84="-168,-60,+320")
print pyproj.Proj(**kwproj)(lonref, latref)

Both transforms give the same result.

Try the same parameters with “cs2cs” changes the results as expected.
Did I miss something?

···


Stephane Raynaud

Stephane Raynaud wrote:

Hi,

it seems that pyproj.Proj does not take into account the "towgs84" optional parameter.
Here is what I simply tried:

from mpl_toolkits.basemap import *
lonref = -3.
latref = 47.

kwproj = dict(proj="lcc", a=6378249.2, b=6356515., x_0=600000., y_0=200000.,
    lon_0="2d20'14.025", lat_0="46d48'", lat_1="45d53'56.108", lat_2="47d41'45.652")
print pyproj.Proj(**kwproj)(lonref, latref)

kwproj.update(towgs84="-168,-60,+320")
print pyproj.Proj(**kwproj)(lonref, latref)

Both transforms give the same result.

Try the same parameters with "cs2cs" changes the results as expected.
Did I miss something?

--
Stephane Raynaud

Stephanie: All the arguments you pass to the Proj instance were used. I don't pretend to understand what's supposed to be happening here, but I guess you are mis-specifying or mis-interpreting some of the proj arguments. The command-line version of proj gives the same answer:

echo "-3.0 47.0" | proj +proj='lcc' +units=m +a=6378249.2 +lon_0="2d20'14.025" +y_0=200000.0 +b=6356515.0 +x_0=600000.0 +lat_2="47d41'45.652" +lat_1="45d53'56.108" +lat_0="46d48'"
194411.84 236007.03

echo "-3.0 47.0" | proj +proj='lcc' +units=m +a=6378249.2 +lon_0="2d20'14.025" +y_0=200000.0 +b=6356515.0 +x_0=600000.0 +lat_2="47d41'45.652" +lat_1="45d53'56.108" +lat_0="46d48'" +towgs84="-168,-60,+320"
194411.84 236007.03

-Jeff

···

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