Perhaps you need tpo perform an Affine transformation n one of these files.
Instructions are provided below as well as in the 5.0 User's guide, Appendix H.
Affine Transformations
MapInfo also provides the ability to define rotated or skewed coordinate systems
by allowing an optional Affine Transformation in any coordinate system
definition. (This can be done in MapInfo versions 4.1.2 and later.) A
coordinate system can also be defined with Bounds and an Affine Transformation.
In that case, add 3000 to the projection number, enter the Affine parameters
(A,B,C,D,E,F) and then list the Bounds (x1,y1,x2,y2). The general form is:
Name, Projection Number + 3000, projection components (from Appendix F), Affine
units, A, B, C, D, E, F, x1, y1, x2, y2
An example of a MAPINFOW.PRJ line with a rotated Affine transformation might
look like this with the Affine parameters in Bold and Bounds in Italics:
"Equal Area for GA (NAD 27)", 3009, 62, 7, -96, 23, 29.5, 45.5, 0, 0, 7,
-0.00000000001, 1, -116.071, -1, -0.00000000001, -50.5312, -6972009.20702,
-16901023.2253, 26829936.181, 16900922.1627
Description of an Affine transformation
An Affine transformation has the following form:
x' = Ax + By + C
y' = Dx + Ey + F
In these equations, the base coordinates (x, y) are transformed to produce the
derived coordinates (x', y'). The six constants A through F determine the
effect of the transformation and MapInfo uses the post multiply method for
homogenous 2D coordinate systems. This can be considered a matrix operation as
follows:
A B C X X
?
D E F * Y = Y?
0 0 1 1 1 Where (X,Y) and
(X?,Y?) are as defined above.
To do various types of Affine transformations the values of A, B, B, D, E, and F
need to be determined. It is fairly easy to define the basic
Transformations\Translations, Rotations, Scaling in X, Scaling in Y, Shearing in
X and Shearing in Y that can be done using an Affine Transformation.
Transformation: C and F are the values you want (0, 0) to go to, A=E=1 and
B=D=0. So, to move the coordinate system so the origin is at (5, 2) the values
would be: A=1, B=0, C=5, D=0, E=1, and F=2.
Rotation about the origin: A=E=cos (angle to rotate), -B=D=sin (angle to
rotate), C=F=0. So, to rotate 60 degree counterclockwise around the origin,
A=.5,B=-.866, C=0, D= .866, E= .5, and F=0.
To Scale in the X direction: A is the scale you want to use. E =1 and the rest
are 0. So, to scale to 3 times the size in the X direction the values would be
A=3, B=0, C=0, D=0, E= 1, F=0.
To Scale in the Y direction: E is the scale you want to use. A =1 and the rest
are 0. So, to scale to 5 times the size in the Y direction the values would be
A=1, B=0, C=0, D=0, E= 5, F=0.
To Scale Overall: just make sure that A and E are equal.
To Shear in the X direction: A = E = 1, B is the shear factor and the rest are
0. So, to Shear by 5 units in the X direction then A=1, B=5, C=0, D= 0, E=1, F=
0.
To Shear in the Y direction: A = E = 1, D is the Shear factor and the rest are
0. So, to Shear by 4 units in the Y direction then A=1, B=0, C=0, D= 4, E=1, F=
0.
Now to get a General Affine Transformation: do a pre-matrix multiplication of
the basic pieces of the transformation. Make sure to put the first operation on
the right. So, to Translate to (5,2) Rotate 60 degrees and then Shear 5 units
in Y and then Translate to (3, 2). The values would be A=.5, B= -.866, C=6.232,
D=3.366, E=-2.23, F=22.758.
For more general information, please consult a basic computer graphics book
noting that everything can be turned into pre-multiplication by transposing the
above matrices. See also the MapBasic Reference for a discussion of Affine
transformation in the CoordSys section.
Regards,
-Bill
Mail List:owner-mapinfo-l
From: "GGS/GGS" <[EMAIL PROTECTED]> on 05/19/99 04:12
AM GMT
To: [EMAIL PROTECTED]
cc:
Subject: MI Hello Mapper
We usually use MapInfo for developing some GIS applications. We want to
know about translation, rotation, and scaling within MapInfo Professional,
mainly for translation or let's say : changing Map coordinat. I have
already tried to change map coordinat using export and import facilities,
and its Set Transformation as well, but not gave the
expected result.
The translation coordinat is very important when we have two identically
maps with diferent original coordinats. We want to make them become one
coordinat orientation. Could you give the solutions?
Sometimes we find two identicaly maps with different position. It seems we
have to rotate one of them to make it fit each other. What is the answer
for this case?
We sometimes find scaling case as well. We have two same objects, one is
smaller than the other. How to make it larger or smaller by scalling (or
anything) until we find they fit each other?
Any solution will be appreciated
Komang
PT. Ganeshaglobal Sarana
Denpasar Bali
[EMAIL PROTECTED]
----------------------------------------------------------------------
To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put
"unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]
