private static IndexArray Calculate(
NdArray <T> source,
int filterAxis,
Func <NdArray <T>, bool> predicate,
out IReadOnlyDictionary <int, int> axisIndexMap)
{
var tmpAxesMap = new Dictionary <int, int>();
var from = 0;
var to = 0;
foreach (var part in source.AsEnumerable(filterAxis))
{
if (predicate(part))
{
tmpAxesMap.Add(from, to);
++from;
}
++to;
}
axisIndexMap = tmpAxesMap;
var newShape = source.Shape.ToArray();
newShape[filterAxis] = from;
return(newShape);
}