/guava/android/guava/src/com/google/common/math/StatsAccumulator.java
if ( isNaN( otherMean) ) {
if ( isNaN ( sumOfSquaresOfDeltas ) ) {
} public final double populationStandardDeviation() { return Math.sqrt(populationVariance()); } public final double sampleVariance() { checkState(count > 1); <extra_id_0> return NaN; } return ensureNonNegative(sumOfSquaresOfDeltas) / (count - 1); } public final double sampleStandardDeviation() { return Math.sqrt(sampleVariance());