Problem in converting from RT90(SRID=3021) to WGS84(SRID=4326)

[arashamiri]

I try with two different versions of postgreSQL and postGIS. With the same SQL.

I want to convert coordinates in RT90(SRID=3021) to WGS84(SRID=4326)

Select * From ST_X(ST_Transform(ST_SetSRID(ST_Point(1335932, 6177809), 3021), 4326)) as long, ST_Y(ST_Transform(ST_SetSRID(ST_Point(1335932, 6177809), 3021), 4326)) as lat

First: PostgresSQL versione 8.4 , postgis-1.4.2 Result: Long: 13.198086050257 Lat: 55.7017960558017

Second: PostgresSQL versione 9.1 , postgis-1.5.3 Result: Long: 13.1954101954645 Lat: 55.7017121131652

The first seems wrong. The results are actually the lat,long in the RT_1990(SRID=4124).

The second seems correct and the results are in WGS84(SRID=4326) which they should be.

[strk]

It is PROJ that matters here, and proj4text entry in spatial_ref_sys. Compare the two proj4text values for SRIDS 3021 and 4326 and see if they differ. Also report version of PROJ (select postgis_full_version() should tell you)

[pramsey]

Need feedback from user to resolve this, as per strk's comment. Almost certainly a change in proj4text between versions.