Statistics

Basic statistics over arrays of int32_t. More...

Typedefs
typedef bool(*	pbl_stats_filter_t) (int index, int32_t value, void *context)
	Filter of the values included in pbl_stats_calculate().

Enumerations
enum	pbl_stats_op {   PBL_STATS_OP_SUM = (1 << 0) , PBL_STATS_OP_AVERAGE = (1 << 1) , PBL_STATS_OP_MIN = (1 << 2) , PBL_STATS_OP_MAX = (1 << 3) ,   PBL_STATS_OP_COUNT = (1 << 4) , PBL_STATS_OP_CONSECUTIVE = (1 << 5) , PBL_STATS_OP_CONSECUTIVE_FIRST = (1 << 6) , PBL_STATS_OP_MEDIAN = (1 << 7) }
	Operations of pbl_stats_calculate(), combined as a bit field. More...

Functions
void	pbl_stats_calculate (enum pbl_stats_op op, const int32_t *data, size_t num_data, pbl_stats_filter_t filter, void *context, int32_t *basic_out)
	Calculate basic statistics over an array.
int32_t	pbl_stats_weighted_median (const int32_t *vals, const int32_t *weights_x100, size_t num_data)
	Calculate the weighted median of an array.

Detailed Description

Basic statistics over arrays of int32_t.

int32_t out[2];
 
pbl_stats_calculate(PBL_STATS_OP_SUM | PBL_STATS_OP_MAX, samples, num_samples, NULL, NULL,
                    out);
// out[0] is the sum, out[1] the maximum

Typedef Documentation

pbl_stats_filter_t

typedef bool(* pbl_stats_filter_t) (int index, int32_t value, void *context)

Filter of the values included in pbl_stats_calculate().

Parameters

index	Index of the value in the data array.
value	Value.
context	Filter data.

Returns

true to include the value.

Enumeration Type Documentation

pbl_stats_op

enum pbl_stats_op

Operations of pbl_stats_calculate(), combined as a bit field.

With a filter, every operation only considers the values it accepts.

Enumerator
PBL_STATS_OP_SUM	Sum.
PBL_STATS_OP_AVERAGE	Average, truncated; 0 without values.
PBL_STATS_OP_MIN	Minimum; INT32_MAX without values.
PBL_STATS_OP_MAX	Maximum; INT32_MIN without values.
PBL_STATS_OP_COUNT	Number of values included; the number of data points without a filter.
PBL_STATS_OP_CONSECUTIVE	Longest run of consecutive values included; the number of data points without a filter.
PBL_STATS_OP_CONSECUTIVE_FIRST	Length of the run of included values at the start of the data.
PBL_STATS_OP_MEDIAN	Median; the lower of the two middle values for an even count.

Function Documentation

pbl_stats_calculate()

void pbl_stats_calculate	(	enum pbl_stats_op	op,
		const int32_t *	data,
		size_t	num_data,
		pbl_stats_filter_t	filter,
		void *	context,
		int32_t *	basic_out
	)

Calculate basic statistics over an array.

Results are written to basic_out in the order of enum pbl_stats_op, without gaps: for PBL_STATS_OP_MAX | PBL_STATS_OP_SUM, basic_out[0] is the sum and basic_out[1] the maximum.

Parameters

	op	Operations, a combination of enum pbl_stats_op.
	data	Values. Nothing is written if NULL.
	num_data	Number of values.
	filter	Filter, or NULL to include every value.
	context	Filter data.
[out]	basic_out	One result per operation in op.

pbl_stats_weighted_median()

int32_t pbl_stats_weighted_median	(	const int32_t *	vals,
		const int32_t *	weights_x100,
		size_t	num_data
	)

Calculate the weighted median of an array.

The weighted median is the value x[k] such that the total weight of the values below it and the total weight of the values above it are each at most half the total weight. When two values qualify, their mean is returned. Uses integer division throughout and allocates a temporary copy with calloc().

Parameters

vals	Values.
weights_x100	Positive weights, scaled by 100.
num_data	Number of values.

Returns

Weighted median, or 0 for invalid arguments, zero total weight or allocation failure.