NetCDF functions

This is the list of all the functions related to NetCDF data.

`abs()`	Computes the absolute value
`acos()`	Computes the arc cosine
`append()`	Appends the given data to file
`asin()`	Computes the arc sine
`atan()`	Computes the arc tangent
`atan2()`	Computes the arc tangent of 2 `Fieldset` objects
`attributes()`	Returns the attributes of the current `NetCdf` variable
`cos()`	Computes the cosine
`dimension_names()`	Returns a list of the `NetCdf`’s dimension names.
`dimensions()`	Returns a list of the `NetCdf`’s dimensions.
`div()`	Computes the integer part of a divison
`exp()`	Computes the exponential
`file()`	Returns a file handler for the specified filename
`global_attributes()`	Returns the `NetCdf` global metadata
`max()`	Maximum
`min()`	Minimum
`mod()`	Computes the integer remainder of a divison
`netcdf_auto_rescale_values_to_fit_packed_type()`	Sets the behaviour of `NetCdf` value handling
`netcdf_auto_scale_values()`	Sets the behaviour of `NetCdf` value handling
`netcdf_auto_translate_times()`	Sets the behaviour of `NetCdf` value handling
`netcdf_preserve_missing_values()`	Sets the behaviour of `NetCdf` value handling
`netcdf_visualiser()`	Defines visualisation for `NetCdf` data
`read()`	Reads the given file and returns a variable of the appropriate type
`setcurrent()`	Sets the variable on which `NetCdf` functions will operate
`sgn()`	Computes the sign
`sin()`	Computes the sine
`sqrt()`	Computes the square root
`tan()`	Computes the tangent
`value()`	Returns a value from the current `NetCdf` variable
`values()`	Returns the values from a data object
`variables()`	Returns the names of the variables in a `NetCdf`
`write()`	Writes/appends the given data to file