neworig

Orient regular data grid to oblique aspect

Syntax

[Z,lat,lon] = neworig(Z0,R,origin)
[Z,lat,lon] = neworig(Z0,R,origin,'forward')
[Z,lat,lon] = neworig(Z0,R,origin,'inverse')


Description

[Z,lat,lon] = neworig(Z0,R,origin) and [Z,lat,lon] = neworig(Z0,R,origin,'forward') will transform regular data grid Z0 into an oblique aspect, while preserving the matrix storage format. In other words, the oblique map origin is not necessarily at (0,0) in the Greenwich coordinate frame. This allows operations to be performed on the matrix representing the oblique map. For example, azimuthal calculations for a point in a data grid become row and column operations if the data grid is transformed so that the north pole of the oblique map represents the desired point on the globe. Specify R as a GeographicCellsReference or GeographicPostingsReference object. The RasterSize property of R must be consistent with size(Z).

[Z,lat,lon] = neworig(Z0,R,origin,'inverse') transforms the regular data grid from the oblique frame to the Greenwich coordinate frame.

The neworig function transforms a regular data grid into a new matrix in an altered coordinate system. An analytical use of the new matrix can be realized in conjunction with the newpole function. If a selected point is made the north pole of the new system, then when a new matrix is created with neworig, each row of the new matrix is a constant distance from the selected point, and each column is a constant azimuth from that point.

Limitations

neworig only supports data grids that cover the entire globe.

Examples

Load elevation raster data and a geographic cells reference object. Then, transform the map so that Sri Lanka is at the North Pole.

load topo60c
origin = newpole(7,80);
Z = neworig(topo60c,topo60cR,origin);
axesm miller
gridm on
lat = linspace(-90,90,90);
lon = linspace(-180,180,180);
surfm(lat,lon,Z)
demcmap(topo60c)
tightmap

Version History

Introduced before R2006a

R2024b: neworig does not accept referencing vectors or referencing matrices as input

The neworig function does not accept referencing vectors or referencing matrices as input. Use a geographic raster reference object, specified as a GeographicCellsReference or GeographicPostingsReference object, as input instead. Reference objects have several advantages over referencing vectors and referencing matrices.

• Unlike referencing vectors and referencing matrices, reference objects have properties that document the size of the associated raster, its geographic limits, and the direction of its rows and columns.

• You can manipulate the limits of geographic rasters associated with reference objects using the geocrop function.

• You can manipulate the size and resolution of geographic rasters associated with reference objects using the georesize function.

To update your code, create a geographic reference object.

• Create a geographic reference object for a raster of cells by using the georefcells function.

• Create a geographic reference object for a raster of regularly posted samples by using the georefpostings function.

• Convert from a referencing vector to a geographic reference object by using the refvecToGeoRasterReference function.

• Convert from a referencing matrix to a geographic reference object by using the refmatToGeoRasterReference function.

Once you have created a reference object, replace uses of the referencing vector or referencing matrix in your code with the reference object.

R2023b: neworig will not accept referencing vectors or referencing matrices as input

When you specify a referencing vector or referencing matrix as input, the neworig function issues a warning that it will not accept referencing vectors or referencing matrices as input in a future release.