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<font face="Times New Roman, Times, serif">Hi Frank and all, happy
new year!<br>
<br>
Is the following possible with Proj? I am working with historical
maps that are rotated with respect to a well known
epsg-projection, see for example<br>
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<a href="http://mapserver.sara.nl/a1000/bladgrenzen.html">http://mapserver.sara.nl/a1000/bladgrenzen.html</a><br>
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<font face="Times New Roman, Times, serif">The blue squares are the
sheets of the map 1:1000 of Amsterdam after 1940, in epsg:28992,
the red squares are the same sheets before 1940 in a local
coordinate system. I know the conversion coefficients for the two
coordinate systems: a simple six-value transformation of the form:<br>
<br>
xnew = a*xold + b*yold + c<br>
ynew = d*xold + e*yold + f<br>
<br>
I would like to access the second map via a proj-string. For that,
I would have to expand proj with a procedure that takes the six
coefficients (a-f) and generates the transformed coordinates after
the regular transformation.<br>
<br>
Is this possible? Can anyone give me some pointers where to look
in the proj-code? Conceptually, it looks simple to me, but I don't
know where to start.<br>
<br>
Jan<br>
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