MATLAB: In MAPVIEW does the Geographic data display a bigger bounded picture than the “Boundingbox” specified in SHAPEREAD

boundingboxMapping Toolboxmapviewshaperead

When SHAPEREAD is used for specifying "Boundingbox" the image displayed is bigger than the "Boundingbox" defined using SHAPEREAD('filename', 'Boundingbox', bbox). For example:

 bbox = [10.091 2.308; 10.093 2.309] * 1e5

the displayed data are:

 xmin = 1002935
 xmax = 1011184
 ymin = 229296
 ymax = 239445

Best Answer

Buffer space around the edge is always provided in map view. To work around this issue, the POLYBOOL function in the Mapping Toolbox can be used to filter out L-shaped, corner-wrapping features. For more information regarding this function, enter:

doc polybool

at the MATLAB Command Prompt.

Related Solutions

MATLAB: Is it possible to make ‘geostruct2’ without using SHAPEREAD

This enhancement has been incorporated in Release 2008a (R2008a). For previous product releases, read below for any possible workarounds:

There is no standard way to make 'geostruct2' data structure without using SHAPEREAD. As a workaround, one can create a 'geostruct2' data structure as in the following example:

S = struct('Geometry','Line','BoundingBox',[0 0;3 3],'X',[1 2 2 1 1],'Y',[1 1 2 2 1]);
figure,mapshow(S)

The above code makes a 'geostruct2' data structure S for a polygonal object.

MATLAB: Do I receive an error when I use GRADIENTM function in Mapping Toolbox 3.0 (R2009b)

This error can occur if the regular data grid referenced in the worldfile is in some projected coordinate system, and not a geographic (latitude-longitude) system. GRADIENTM is not applicable in this case. Instead, you should use the GRADIENT function, which is part of base MATLAB:

[dx,dy] = gradient(dtm);

and scale the first return value by R(2,1) - the width of a raster cell in the x-direction -- and the second by R(1,2) --the (signed) height of a raster cell in the y-direction.

dx = dx / R(2,1);
dy = dy / R(1,2);

This will convert the gradient arrays from change per column or row to change per x and y in the projected system.

For more information on the GRADIENT function, execute the following in the MATLAB command prompt:

doc gradient

Best Answer

Related Solutions

MATLAB: Is it possible to make ‘geostruct2’ without using SHAPEREAD

MATLAB: Do I receive an error when I use GRADIENTM function in Mapping Toolbox 3.0 (R2009b)

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