Function Names
quantile, quantile ignore zeroDescription
Quantiles are points in a distribution that relate to the rank order of values in that distribution. As an example, the middle
quantile (quantile parameter p = 0.5) is referred as median() function. B4P also supports this function directly.
Quantile calculation is the inverse of the empirical probability distribution. Following calculation rule is applied:
n refers to the number numeric values provided. p is referred as the quantile parameter.
Examples:
- For the 1st quartile, use p = 0.25
- For the 2nd quartile (median), use p = 0.5, or the median() function
- For the 3rd quartil, use p = 0.75
The function quantile ignore zero ignores all zero values provided. If the sequence of values does only contain zeros, then an exception will be asserted because the quantile cannot be calculated.
Call as: function
Parameter count
2
Parameters
| No. | Type | Description |
|---|---|---|
| 1 input |
numeral | Quantile parameter The value must lie between 0 and 1. |
| 2 input |
parameter set | Set of values The parameter set must contain at least one numeric element which will be included in the calculation. Blank strings are tolerated (no exceptions asserted) and ignored as well (not treated as zero). The values do not need to be ordered in ascending order. This function will take of it. |
| Opt. 3 input |
numeral | Starting parameter set element to include Points to the starting parameter set element. Negative indexing is allowed here, i.e. -1 refers to last element in the parameter set. Default value: 0 |
| Opt. 4 input |
numeral | Ending parameter set element to include Points to the ending parameter set element. Negative indexing is allowed here, i.e. -1 refers to last element in the parameter set. Default value: Last value |
Return value
| Type | Description |
|---|---|
| numeral | Calculated quantile |
Exceptions
Quantile parameter not between 0 and 1
No numbers available to calculate
Examples
ps[] = { 0, 0.0001, 0.1, 0.2, 0.25, 1/3, 0.5, 2/3, 0.75, 0.8, 0.9, 0.9999, 1.0 };
for all parameters( ps[], p[] )
{
echo("p: ", p[]," quantile = ", quantile( p[], { 1, 2, 2, 3, 5, 8, 9, 12, 12, 13 } ) );
}
echo( "Call with 4 parameters: ", quantile( 0.5, { 8,7,6,5,4,3,2,1 }, 1, 3 ) );
// Values 7,6,5 are calculated and result in 6.Output
p: 0 quantile = 1
p: 0.0001 quantile = 1
p: 0.1 quantile = 1.5
p: 0.2 quantile = 2
p: 0.25 quantile = 2
p: 0.3333333333 quantile = 3
p: 0.5 quantile = 6.5
p: 0.6666666667 quantile = 9
p: 0.75 quantile = 12
p: 0.8 quantile = 12
p: 0.9 quantile = 12.5
p: 0.9999 quantile = 13
p: 1.0 quantile = 13
Call with 4 parameters: 6