apex-stats
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Statistical library for Salesforce Apex
The stats library contains a simple Stats class for statistical calculations. It works on lists of Decimal numbers so that the required precision can be obtained.
Stats
| Modifier and type | Method |
|---|---|
static Decimal |
mean(List<Decimal> nums) |
static Decimal |
geometricMean(List<Decimal> nums) |
static Decimal |
harmonicMean(List<Decimal> nums) |
static Decimal |
median(List<Decimal> nums) |
static Decimal |
lowerQuartile(List<Decimal> nums) |
static Decimal |
upperQuartile(List<Decimal> nums) |
static Decimal |
midhinge(List<Decimal> nums) |
static Decimal |
min(List<Decimal> nums) |
static Decimal |
max(List<Decimal> nums) |
static Decimal |
range(List<Decimal> nums) |
static Decimal |
midrange(List<Decimal> nums) |
static Decimal |
mode(List<Decimal> nums) |
static Decimal |
variance(List<Decimal> nums) |
static Decimal |
sampleVariance(List<Decimal> nums) |
static Decimal |
standardDeviation(List<Decimal> nums) |
static Decimal |
sampleStandardDeviation(List<Decimal> nums) |
static Decimal |
coefficientOfVariation(List<Decimal> nums) |
Measures of centrality
mean
Arithmetic mean.
geometricMean
Geometric mean. All values need to be positive, otherwise it does not exist.
harmonicMean
Harmonic mean. All values need to be positive, otherwise it does not exist.
median
Median, considered to be the middle element for odd number of elements, and an arithmetic mean of two middle elements for even number of elements. For example, the median of (1, 2, 3, 4, 5) is 3, while the median of (1, 2, 3, 4) is 2.5.
lowerQuartile
Median of those elements that are smaller than the median. For example, in list (1, 2, 3, 4, 5, 6, 7), the median is 4. (1, 2, 3) are smaller than 4, therefore the lowerQuartile is the median of that list, which is 2.
upperQuartile
Median of those elements that are larger than the median. For example, in list (1, 2, 3, 4, 5, 6, 7), the median is 4. (5, 6, 7) are smaller than 4, therefore the upperQuartile is the median of that list, which is 6.
midhinge
Mean of lowerQuartile and upperQuartile values.
min
Minimal value.
max
Maximal value.
range
Range of all values, which is the difference between max and min values.
midrange
Mean of min and max values.
mode
Value that appears most often in the list. This might not be a unique value.
Measures of dispersion
variance
Variance of values.
sampleVariance
Variance of values corrected for bias.
standardDeviation
Standard deviation of values, calculated as a square root of variance.
sampleStandardDeviation
Standard deviation corrected for bias, calculated as a square root of sampleVariance.
coefficientOfVariation
Calculated as standardDeviation divided by mean.
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