CHECK_SHAPEFILE Name
CHECK_SHAPEFILE
Purpose
Look at details of a shapefile. Show some access commands.
Category
Calling Sequence
check_shapefile, file Inputs
file = name of shapefile. in
Keyword Parameters
Outputs
Common Blocks
Notes
Notes: How to deal with attributes of an entity
Each entity in the shape file has a number of
attributes. Those attributes have values.
This routine will find the possible values of a selected
attribute.
To access a shape file:
s = obj_new('IDLffShape',file)
The number of entities in the file is found by:
s->IDLffShape::GetProperty, n_entities=num
The names of the attributes are found by:
s->IDLffShape::GetProperty,attribute_names=attnames
To get the i'th (i<num) entity in structure t:
t = s->IDLffShape::GetEntity(i,/attributes)
The attribute structure is then
att = *t.attributes
The value of the j'th attribute is
val = att.(j)
To apply this must known j and the target value.
Must free all pointers in the entity structure:
ptr_free,t.VERTICES,t.MEASURE,t.PARTS,t.PART_TYPES,t.ATTRIBUTES
Also destory the object when done:
obj_destroy, s
Modification History
R. Sterner, 2004 Apr 05
R. Sterner, 2004 Jul 15 --- Listed Number of entities, type.
R. Sterner, 2010 Apr 30 --- Converted arrays from () to [].
Copyright (C) 2004, Johns Hopkins University/Applied Physics Laboratory
This software may be used, copied, or redistributed as long as it is not
sold and this copyright notice is reproduced on each copy made. This
routine is provided as is without any express or implied warranties
whatsoever. Other limitations apply as described in the file disclaimer.txt.