Module: H3::Inspection

Extended by:
Bindings::Base
Included in:
H3
Defined in:
lib/h3/inspection.rb

Overview

Index inspection functions.

See Also:

Instance Method Summary collapse

Methods included from Bindings::Base

attach_predicate_function, extended

Instance Method Details

#base_cell(h3_index) ⇒ Integer

Derives the base cell number of the given H3 index

Examples:

Derive the base cell number of a H3 index

H3.base_cell(617700440100569087)
20

Parameters:

  • h3_index (Integer) —

    A valid H3 index

Returns:

  • (Integer) —

    Base cell number



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# File 'lib/h3/inspection.rb', line 35

attach_function :base_cell, :h3GetBaseCell, %i[h3_index], :int

#class_3_resolution?(h3_index) ⇒ Boolean

Determine whether the given H3 index has a resolution with Class III orientation.

Examples:

Check if H3 index has a class III resolution.

H3.class_3_resolution?(599686042433355775)
true

Parameters:

  • h3_index (Integer) —

    A valid H3 index.

Returns:

  • (Boolean) —

    True if the H3 index has a class III resolution.



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# File 'lib/h3/inspection.rb', line 75

attach_predicate_function :class_3_resolution?, :h3IsResClassIII, %i[h3_index], :bool

#faces(h3_index) ⇒ Array<Integer>

Find all icosahedron faces intersected by a given H3 index.

Examples:

Find icosahedron faces for given index

H3.faces(585961082523222015)
[1, 2, 6, 7, 11]

Parameters:

  • h3_index (Integer) —

    A H3 index.

Returns:

  • (Array<Integer>) —

    Faces. Faces are represented as integers from 0-19, inclusive.



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# File 'lib/h3/inspection.rb', line 127

def faces(h3_index)
  max_faces = max_face_count(h3_index)
  out = FFI::MemoryPointer.new(:int, max_faces)
  Bindings::Private.h3_faces(h3_index, out)
  # The C function returns a sparse array whose holes are represented by -1.
  out.read_array_of_int(max_faces).reject(&:negative?).sort
end

#from_string(h3_string) ⇒ Integer

Derives the H3 index for a given hexadecimal string representation.

Examples:

Derive the H3 index from the given hexadecimal form.

H3.from_string("8928308280fffff")
617700169958293503

Parameters:

  • h3_string (String) —

    A H3 index in hexadecimal form.

Returns:

  • (Integer) —

    H3 index



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# File 'lib/h3/inspection.rb', line 48

attach_function :from_string, :stringToH3, %i[string], :h3_index

#max_face_count(h3_index) ⇒ Integer

Returns the maximum number of icosahedron faces the given H3 index may intersect.

Examples:

Check maximum faces

H3.max_face_count(585961082523222015)
5

Parameters:

  • h3_index (Integer) —

    A H3 index.

Returns:

  • (Integer) —

    Maximum possible number of faces



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# File 'lib/h3/inspection.rb', line 116

attach_function :max_face_count, :maxFaceCount, %i[h3_index], :int

#pentagon?(h3_index) ⇒ Boolean

Determine whether the given H3 index is a pentagon.

Examples:

Check if H3 index is a pentagon

H3.pentagon?(585961082523222015)
true

Parameters:

  • h3_index (Integer) —

    A valid H3 index.

Returns:

  • (Boolean) —

    True if the H3 index is a pentagon.



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# File 'lib/h3/inspection.rb', line 61

attach_predicate_function :pentagon?, :h3IsPentagon, %i[h3_index], :bool

#resolution(h3_index) ⇒ Integer

Derive the resolution of a given H3 index

Examples:

Derive the resolution of a H3 index

H3.resolution(617700440100569087)
9

Parameters:

  • h3_index (Integer) —

    A valid H3 index

Returns:

  • (Integer) —

    Resolution of H3 index



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# File 'lib/h3/inspection.rb', line 22

attach_function :resolution, :h3GetResolution, %i[h3_index], Resolution

#to_string(h3_index) ⇒ String

Derives the hexadecimal string representation for a given H3 index.

Examples:

Derive the given hexadecimal form for the H3 index

H3.to_string(617700169958293503)
"89283470dcbffff"

Parameters:

  • h3_index (Integer) —

    A valid H3 index.

Returns:

  • (String) —

    H3 index in hexadecimal form.



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# File 'lib/h3/inspection.rb', line 99

def to_string(h3_index)
  h3_str = FFI::MemoryPointer.new(:char, H3_TO_STR_BUF_SIZE)
  Bindings::Private.h3_to_string(h3_index, h3_str, H3_TO_STR_BUF_SIZE)
  h3_str.read_string
end

#valid?(h3_index) ⇒ Boolean

Determine whether the given H3 index is valid.

Examples:

Check if H3 index is valid

H3.valid?(599686042433355775)
true

Parameters:

  • h3_index (Integer) —

    A H3 index.

Returns:

  • (Boolean) —

    True if the H3 index is valid.



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# File 'lib/h3/inspection.rb', line 88

attach_predicate_function :valid?, :h3IsValid, %i[h3_index], :bool