docs: function variance( lambda, options ) {
  	/* jshint newcap:false */
  	var opts = {},
  		ctor,
  		err,
  		out,
  		dt,
  		d;
  
  	if ( isNumber( lambda ) || isnan( lambda ) ) {
  		return variance1( lambda );
  	}
  	if ( arguments.length > 1 ) {
  		err = validate( opts, options );
  		if ( err ) {
  			throw err;
  		}
  	}
  	if ( isMatrixLike( lambda ) ) {
  		if ( opts.copy !== false ) {
  			dt = opts.dtype || 'float64';
  			ctor = ctors( dt );
  			if ( ctor === null ) {
  				throw new Error( 'variance()::invalid option. Data type option does not have a corresponding array constructor. Option: `' + dt + '`.' );
  			}
  			// Create an output matrix:
  			d = new ctor( lambda.length );
  			out = matrix( d, lambda.shape, dt );
  		} else {
  			out = lambda;
  		}
  		return variance5( out, lambda );
  	}
  	if ( isTypedArrayLike( lambda ) ) {
  		if ( opts.copy === false ) {
  			out = lambda;
  		} else {
  			dt = opts.dtype || 'float64';
  			ctor = ctors( dt );
  			if ( ctor === null ) {
  				throw new Error( 'variance()::invalid option. Data type option does not have a corresponding array constructor. Option: `' + dt + '`.' );
  			}
  			out = new ctor( lambda.length );
  		}
  		return variance6( out, lambda );
  	}
  	if ( isArrayLike( lambda ) ) {
  		// Handle deepset first...
  		if ( opts.path ) {
  			opts.sep = opts.sep || '.';
  			return variance4( lambda, opts.path, opts.sep );
  		}
  		// Handle regular and accessor arrays next...
  		if ( opts.copy === false ) {
  			out = lambda;
  		}
  		else if ( opts.dtype ) {
  			ctor = ctors( opts.dtype );
  			if ( ctor === null ) {
  				throw new TypeError( 'variance()::invalid option. Data type option does not have a corresponding array constructor. Option: `' + opts.dtype + '`.' );
  			}
  			out = new ctor( lambda.length );
  		}
  		else {
  			out = new Array( lambda.length );
  		}
  		if ( opts.accessor ) {
  			return variance3( out, lambda, opts.accessor );
  		}
  		return variance2( out, lambda );
  	}
  	return NaN;
  }