netcdf

This library currently only supports netcdf v4

Crystal bindings to libnetcdf v4.

Based on swillner's NodeJS bindings

Installation

NetCDF must be installed: brew install hdf5 netcdf

Add this to your application's shard.yml:

dependencies:
  netcdf:
    github: fridgerator/netcdfcr

Usage

require "netcdf"

file = NetCDF::File.open("path/to/file.nc")
group = file.groups.first
attr = group.attributes.first
puts attr.name
puts attr.value

variable = group.variables.first
puts variable.name
puts variable.read(0) # one dimension
puts variable.read(0, 0, 0) # 3 dimensions
puts variable.read_slice(0, 10, 0, 1, 0, 1) # read slice of 10 for 3 dimensions

attr = variable.attributes.first
puts attr.value

file.close

Classes

File

Properties:

• id: NetCDF file id

Methods:

• close : Close file
• sync : Sync file to disk
• add_group : Adds a group to a file
• add_dimension : Adds a dimension to a file
• add_variable : Adds a variable to a file
• attributes : Returns an array of global attributes
• add_attribute : Creates a global attribute

Group

Properties:

• parent_id : NetCDF id of parent
• id : NetCDF id
• name : Group name

Methods:

• full_name : Full name
• unlimited : Returns array of unlimited Dimensions in group
• attributes : Returns an array of attributes
• dimensions : Returns an array of dimensions
• variables : Returns an array of variables
• groups : Returns an array of groups
• add_group : Adds a group within a group
• add_dimension : Adds a dimension to a group
• add_variable : Adds a variable to a Group

Dimension

Properties:

• parent_id : NetCDF id of parent
• id : NetCDF id
• name : Dimension name
• length : Dimension length

Attribute

Properties:

• parent_id : NetCDF id of parent
• id : NetCDF id
• name : Attribute name
• attribute_type : Attribute type Int32

Methods:

• value : Attribute value

Variable

Properties:

• parent_id : NetCDF id of parent
• id : NetCDF id
• name : Variable name
• var_type : Variable type Int32
• ndims : Number of dimensions

Methods:

• attributes : Returns an array of variable attributes
• endianness : Endianness: "little", "big", or "native"
• checksum_mode : Checksum mode: "none" or "fletcher32"
• chunk_mode : Chunk mode: "contiguous", or "chunked"
• chunk_sizes : Array of chunk sizes, one size per dimension
• fill_mode : Boolean switch for fill mode
• fill_value : Fill value
• compression_shuffle : Boolean switch for shuffle
• compression_deflate : Boolean switch for compression
• compression_level : Compression level (1-9)
• read_slice : Reads and returns an array of values (cf. "Specify a Hyperslab") at positions and sizes given for each dimension, readSlice(pos1, size1, pos2, size2, ...) e.g. readSlice(2, 3, 4, 2) gives an array of the values at position 2 for 3 steps along the first dimension and position 4 for 2 steps along the second one.
• read : Reads and returns a single value at positions, one argument per dimension
• add_attribute : Creates an attribute for a variable
• write : Write a value at positions given, write(2, 3, "a") writes "a" at position 2 along the first dimension and position 3 along the second one
• write_slice : Write values from an array (array must be of same type) at positions and sizes given for each dimension. writeSlice(2, 3, 4, 2, [0, 1, 2, 3, 4, 5]) writes the array at position 2 for 3 steps along the first dimension and position 4 for 2 step along the second one

Contributing

1. Fork it ( https://github.com/fridgerator/netcdfcr/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• fridgerator Nick Franken - creator, maintainer