Class: NSWTopo::ESRIHdr
- Inherits:
-
Object
- Object
- NSWTopo::ESRIHdr
- Defined in:
- lib/nswtopo/gis/esri_hdr.rb
Instance Attribute Summary collapse
-
#header ⇒ Object
readonly
Returns the value of attribute header.
-
#nodata ⇒ Object
readonly
Returns the value of attribute nodata.
-
#values ⇒ Object
readonly
Returns the value of attribute values.
Instance Method Summary collapse
-
#initialize(path_or_object, *args) ⇒ ESRIHdr
constructor
A new instance of ESRIHdr.
- #ncols ⇒ Object
- #nrows ⇒ Object
- #rows ⇒ Object
- #write(path) ⇒ Object
Constructor Details
#initialize(path_or_object, *args) ⇒ ESRIHdr
Returns a new instance of ESRIHdr.
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# File 'lib/nswtopo/gis/esri_hdr.rb', line 3 def initialize(path_or_object, *args) @header = case path_or_object when Pathname then path_or_object.sub_ext(".hdr").each_line.map(&:upcase).map(&:split).to_h when ESRIHdr then path_or_object.header.dup end @format = case @header.values_at "PIXELTYPE", "NBITS", "BYTEORDER" when %w[SIGNEDINT 8 I] then "c*" when %w[SIGNEDINT 8 M] then "c*" when %w[SIGNEDINT 16 I] then "s<*" when %w[SIGNEDINT 16 M] then "s>*" when %w[SIGNEDINT 32 I] then "l<*" when %w[SIGNEDINT 32 M] then "l>*" when %w[UNSIGNEDINT 8 I] then "C*" when %w[UNSIGNEDINT 8 M] then "C*" when %w[UNSIGNEDINT 16 I] then "S<*" when %w[UNSIGNEDINT 16 M] then "S>*" when %w[UNSIGNEDINT 32 I] then "L<*" when %w[UNSIGNEDINT 32 M] then "L>*" when %w[FLOAT 32 I] then "e*" when %w[FLOAT 32 M] then "g*" end @nodata = case path_or_object when Pathname case @header.values_at "PIXELTYPE", "NBITS" when %w[SIGNEDINT 8] then args.take(1).pack("c").unpack("c").first when %w[UNSIGNEDINT 8] then args.take(1).pack("C").unpack("C").first when %w[SIGNEDINT 16] then args.take(1).pack("s").unpack("s").first when %w[UNSIGNEDINT 16] then args.take(1).pack("S").unpack("S").first when %w[SIGNEDINT 32] then args.take(1).pack("l").unpack("l").first when %w[UNSIGNEDINT 32] then args.take(1).pack("L").unpack("L").first when %w[FLOAT 32] then args.first else abort @header.inspect end if args.any? when ESRIHdr then path_or_object.nodata end @values = case path_or_object when Pathname data = [] path_or_object.sub_ext(".bil").open("rb") do |file| while !file.eof? data += file.read(32*1024*1024).unpack(@format).map do |value| value == @nodata ? nil : value end end end data when ESRIHdr then args[0] end end |
Instance Attribute Details
#header ⇒ Object (readonly)
Returns the value of attribute header.
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# File 'lib/nswtopo/gis/esri_hdr.rb', line 69 def header @header end |
#nodata ⇒ Object (readonly)
Returns the value of attribute nodata.
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# File 'lib/nswtopo/gis/esri_hdr.rb', line 69 def nodata @nodata end |
#values ⇒ Object (readonly)
Returns the value of attribute values.
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# File 'lib/nswtopo/gis/esri_hdr.rb', line 69 def values @values end |
Instance Method Details
#ncols ⇒ Object
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# File 'lib/nswtopo/gis/esri_hdr.rb', line 75 def ncols @ncols ||= @header["NCOLS"].to_i end |
#nrows ⇒ Object
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# File 'lib/nswtopo/gis/esri_hdr.rb', line 71 def nrows @nrows ||= @header["NROWS"].to_i end |
#rows ⇒ Object
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# File 'lib/nswtopo/gis/esri_hdr.rb', line 79 def rows @values.each_slice ncols end |
#write(path) ⇒ Object
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# File 'lib/nswtopo/gis/esri_hdr.rb', line 56 def write(path) @header.map do |pair| "%-#{@header.keys.map(&:length).max}s %s\n" % pair end.join('').tap do |text| path.sub_ext(".hdr").write text end @values.map do |value| value || @nodata end.pack(@format).tap do |data| path.sub_ext(".bil").binwrite data end end |