Handling and converting analog data. More...

Functions
int	sr_analog_to_float (const struct sr_datafeed_analog analog, float outbuf)
	Convert an analog datafeed payload to an array of floats. More...

const char *	sr_analog_si_prefix (float value, int digits)
	Scale a float value to the appropriate SI prefix. More...

gboolean	sr_analog_si_prefix_friendly (enum sr_unit unit)
	Check if a unit "accepts" an SI prefix. More...

int	sr_analog_unit_to_string (const struct sr_datafeed_analog analog, char *result)
	Convert the unit/MQ/MQ flags in the analog struct to a string. More...

void	sr_rational_set (struct sr_rational *r, int64_t p, uint64_t q)
	Set sr_rational r to the given value. More...

int	sr_rational_eq (const struct sr_rational a, const struct sr_rational b)
	Compare two sr_rational for equality. More...

int	sr_rational_mult (struct sr_rational res, const struct sr_rational a, const struct sr_rational *b)
	Multiply two sr_rational. More...

int	sr_rational_div (struct sr_rational res, const struct sr_rational num, const struct sr_rational *div)
	Divide rational a by rational b. More...

Detailed Description

Handling and converting analog data.

Function Documentation

const char* sr_analog_si_prefix	(	float *	value,
		int *	digits
	)

Scale a float value to the appropriate SI prefix.

Parameters

[in,out]	value	The float value to convert to appropriate SI prefix.
[in,out]	digits	The number of significant decimal digits in value.

Returns: The SI prefix to which value was scaled, as a printable string.

Since: 0.5.0

Definition at line 391 of file analog.c.

gboolean sr_analog_si_prefix_friendly ( enum sr_unit unit )

Check if a unit "accepts" an SI prefix.

E.g. SR_UNIT_VOLT is SI prefix friendly while SR_UNIT_DECIBEL_MW or SR_UNIT_PERCENTAGE are not.

Parameters

[in] unit The unit to check for SI prefix "friendliness".

Returns: TRUE if the unit "accept" an SI prefix.

Since: 0.5.0

Definition at line 430 of file analog.c.

References SR_UNIT_AMPERE, SR_UNIT_FARAD, SR_UNIT_GRAM, SR_UNIT_HENRY, SR_UNIT_HERTZ, SR_UNIT_KELVIN, SR_UNIT_METER_SECOND, SR_UNIT_OHM, SR_UNIT_SECOND, SR_UNIT_SIEMENS, SR_UNIT_VOLT, SR_UNIT_VOLT_AMPERE, SR_UNIT_WATT, and SR_UNIT_WATT_HOUR.

int sr_analog_to_float	(	const struct sr_datafeed_analog *	analog,
		float *	outbuf
	)

Convert an analog datafeed payload to an array of floats.

The caller must provide the #outbuf space for the conversion result, and is expected to free allocated space after use.

Parameters

[in]	analog	The analog payload to convert. Must not be NULL. analog->data, analog->meaning, and analog->encoding must not be NULL.
[out]	outbuf	Memory where to store the result. Must not be NULL.

Return values

SR_OK	Success.
SR_ERR	Unsupported encoding.
SR_ERR_ARG	Invalid argument.

Since: 0.4.0

Definition at line 177 of file analog.c.

References sr_analog_meaning::channels, sr_datafeed_analog::data, sr_datafeed_analog::encoding, sr_analog_encoding::is_bigendian, sr_analog_encoding::is_float, sr_analog_encoding::is_signed, sr_datafeed_analog::meaning, sr_datafeed_analog::num_samples, sr_analog_encoding::offset, sr_rational::p, sr_rational::q, sr_analog_encoding::scale, SR_ERR, SR_ERR_ARG, SR_OK, and sr_analog_encoding::unitsize.

Referenced by sr_a2l_schmitt_trigger(), and sr_a2l_threshold().

Here is the caller graph for this function:

int sr_analog_unit_to_string	(	const struct sr_datafeed_analog *	analog,
		char **	result
	)

Convert the unit/MQ/MQ flags in the analog struct to a string.

The string is allocated by the function and must be freed by the caller after use by calling g_free().

Parameters

[in]	analog	Struct containing the unit, MQ and MQ flags. Must not be NULL. analog->meaning must not be NULL.
[out]	result	Pointer to store result. Must not be NULL.

Return values

SR_OK	Success.
SR_ERR_ARG	Invalid argument.

Since: 0.4.0

Definition at line 472 of file analog.c.

References sr_datafeed_analog::meaning, sr_analog_meaning::mqflags, SR_ERR_ARG, SR_OK, and sr_analog_meaning::unit.

int sr_rational_div	(	struct sr_rational *	res,
		const struct sr_rational *	num,
		const struct sr_rational *	div
	)

Divide rational a by rational b.

The resulting nominator/denominator are reduced if the result would not fit otherwise. If the resulting nominator/denominator are relatively prime, this may not be possible.

It is safe to use the same variable for result and input values.

Parameters

[in]	num	Numerator.
[in]	div	Divisor.
[out]	res	Result.

Return values

SR_OK	Success.
SR_ERR_ARG	Division by zero, denominator of divisor too large, or resulting value too large.

Since: 0.5.0

Definition at line 693 of file analog.c.

References sr_rational::p, sr_rational::q, SR_ERR_ARG, and sr_rational_mult().

Here is the call graph for this function:

int sr_rational_eq	(	const struct sr_rational *	a,
		const struct sr_rational *	b
	)

Compare two sr_rational for equality.

The values are compared for numerical equality, i.e. 2/10 == 1/5.

Parameters

[in]	a	First value.
[in]	b	Second value.

Return values

1	if both values are equal.
0	Otherwise.

Since: 0.5.0

Definition at line 576 of file analog.c.

References sr_rational::p, and sr_rational::q.

int sr_rational_mult	(	struct sr_rational *	res,
		const struct sr_rational *	a,
		const struct sr_rational *	b
	)

Multiply two sr_rational.

The resulting nominator/denominator are reduced if the result would not fit otherwise. If the resulting nominator/denominator are relatively prime, this may not be possible.

It is safe to use the same variable for result and input values.

Parameters

[in]	a	First value.
[in]	b	Second value.
[out]	res	Result.

Return values

SR_OK	Success.
SR_ERR_ARG	Resulting value too large.

Since: 0.5.0

Definition at line 615 of file analog.c.

References sr_rational::p, sr_rational::q, SR_ERR_ARG, and SR_OK.

Referenced by sr_rational_div().

Here is the caller graph for this function:

void sr_rational_set	(	struct sr_rational *	r,
		int64_t	p,
		uint64_t	q
	)

Set sr_rational r to the given value.

Parameters

[out]	r	Rational number struct to set. Must not be NULL.
[in]	p	Numerator.
[in]	q	Denominator.

Since: 0.4.0

Definition at line 509 of file analog.c.

References sr_rational::p, and sr_rational::q.

Functions

Detailed Description

Function Documentation