Returns an accumulator function which incrementally computes the mean directional accuracy.
accumulator function
var accumulator = incrmda();
var m = accumulator();
// returns null
m = accumulator( 2.0, 3.0 );
// returns 1.0
m = accumulator( -5.0, 4.0 );
// returns 0.5
m = accumulator();
// returns 0.5
If provided a value, the accumulator function returns an updated mean directional accuracy. If not provided a value, the accumulator function returns the current mean directional accuracy.
Notes
NaN
or a value which, when used in computations, results inNaN
, the accumulated value isNaN
for all future invocations.forecast value
actual value
mean directional accuracy or null