float.c

postgresql8.3.4源码,开源数据库

				sumX,
				sumX2,
				numerator;

	transvalues = check_float8_array(transarray, "float8_regr_sxx", 6);
	N = transvalues[0];
	sumX = transvalues[1];
	sumX2 = transvalues[2];

	/* if N is 0 we should return NULL */
	if (N < 1.0)
		PG_RETURN_NULL();

	numerator = N * sumX2 - sumX * sumX;
	CHECKFLOATVAL(numerator, isinf(sumX2) || isinf(sumX), true);

	/* Watch out for roundoff error producing a negative numerator */
	if (numerator <= 0.0)
		PG_RETURN_FLOAT8(0.0);

	PG_RETURN_FLOAT8(numerator / N);
}

Datum
float8_regr_syy(PG_FUNCTION_ARGS)
{
	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
	float8	   *transvalues;
	float8		N,
				sumY,
				sumY2,
				numerator;

	transvalues = check_float8_array(transarray, "float8_regr_syy", 6);
	N = transvalues[0];
	sumY = transvalues[3];
	sumY2 = transvalues[4];

	/* if N is 0 we should return NULL */
	if (N < 1.0)
		PG_RETURN_NULL();

	numerator = N * sumY2 - sumY * sumY;
	CHECKFLOATVAL(numerator, isinf(sumY2) || isinf(sumY), true);

	/* Watch out for roundoff error producing a negative numerator */
	if (numerator <= 0.0)
		PG_RETURN_FLOAT8(0.0);

	PG_RETURN_FLOAT8(numerator / N);
}

Datum
float8_regr_sxy(PG_FUNCTION_ARGS)
{
	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
	float8	   *transvalues;
	float8		N,
				sumX,
				sumY,
				sumXY,
				numerator;

	transvalues = check_float8_array(transarray, "float8_regr_sxy", 6);
	N = transvalues[0];
	sumX = transvalues[1];
	sumY = transvalues[3];
	sumXY = transvalues[5];

	/* if N is 0 we should return NULL */
	if (N < 1.0)
		PG_RETURN_NULL();

	numerator = N * sumXY - sumX * sumY;
	CHECKFLOATVAL(numerator, isinf(sumXY) || isinf(sumX) ||
				  isinf(sumY), true);

	/* A negative result is valid here */

	PG_RETURN_FLOAT8(numerator / N);
}

Datum
float8_regr_avgx(PG_FUNCTION_ARGS)
{
	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
	float8	   *transvalues;
	float8		N,
				sumX;

	transvalues = check_float8_array(transarray, "float8_regr_avgx", 6);
	N = transvalues[0];
	sumX = transvalues[1];

	/* if N is 0 we should return NULL */
	if (N < 1.0)
		PG_RETURN_NULL();

	PG_RETURN_FLOAT8(sumX / N);
}

Datum
float8_regr_avgy(PG_FUNCTION_ARGS)
{
	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
	float8	   *transvalues;
	float8		N,
				sumY;

	transvalues = check_float8_array(transarray, "float8_regr_avgy", 6);
	N = transvalues[0];
	sumY = transvalues[3];

	/* if N is 0 we should return NULL */
	if (N < 1.0)
		PG_RETURN_NULL();

	PG_RETURN_FLOAT8(sumY / N);
}

Datum
float8_covar_pop(PG_FUNCTION_ARGS)
{
	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
	float8	   *transvalues;
	float8		N,
				sumX,
				sumY,
				sumXY,
				numerator;

	transvalues = check_float8_array(transarray, "float8_covar_pop", 6);
	N = transvalues[0];
	sumX = transvalues[1];
	sumY = transvalues[3];
	sumXY = transvalues[5];

	/* if N is 0 we should return NULL */
	if (N < 1.0)
		PG_RETURN_NULL();

	numerator = N * sumXY - sumX * sumY;
	CHECKFLOATVAL(numerator, isinf(sumXY) || isinf(sumX) ||
				  isinf(sumY), true);

	PG_RETURN_FLOAT8(numerator / (N * N));
}

Datum
float8_covar_samp(PG_FUNCTION_ARGS)
{
	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
	float8	   *transvalues;
	float8		N,
				sumX,
				sumY,
				sumXY,
				numerator;

	transvalues = check_float8_array(transarray, "float8_covar_samp", 6);
	N = transvalues[0];
	sumX = transvalues[1];
	sumY = transvalues[3];
	sumXY = transvalues[5];

	/* if N is <= 1 we should return NULL */
	if (N < 2.0)
		PG_RETURN_NULL();

	numerator = N * sumXY - sumX * sumY;
	CHECKFLOATVAL(numerator, isinf(sumXY) || isinf(sumX) ||
				  isinf(sumY), true);

	PG_RETURN_FLOAT8(numerator / (N * (N - 1.0)));
}

Datum
float8_corr(PG_FUNCTION_ARGS)
{
	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
	float8	   *transvalues;
	float8		N,
				sumX,
				sumX2,
				sumY,
				sumY2,
				sumXY,
				numeratorX,
				numeratorY,
				numeratorXY;

	transvalues = check_float8_array(transarray, "float8_corr", 6);
	N = transvalues[0];
	sumX = transvalues[1];
	sumX2 = transvalues[2];
	sumY = transvalues[3];
	sumY2 = transvalues[4];
	sumXY = transvalues[5];

	/* if N is 0 we should return NULL */
	if (N < 1.0)
		PG_RETURN_NULL();

	numeratorX = N * sumX2 - sumX * sumX;
	CHECKFLOATVAL(numeratorX, isinf(sumX2) || isinf(sumX), true);
	numeratorY = N * sumY2 - sumY * sumY;
	CHECKFLOATVAL(numeratorY, isinf(sumY2) || isinf(sumY), true);
	numeratorXY = N * sumXY - sumX * sumY;
	CHECKFLOATVAL(numeratorXY, isinf(sumXY) || isinf(sumX) ||
				  isinf(sumY), true);
	if (numeratorX <= 0 || numeratorY <= 0)
		PG_RETURN_NULL();

	PG_RETURN_FLOAT8(numeratorXY / sqrt(numeratorX * numeratorY));
}

Datum
float8_regr_r2(PG_FUNCTION_ARGS)
{
	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
	float8	   *transvalues;
	float8		N,
				sumX,
				sumX2,
				sumY,
				sumY2,
				sumXY,
				numeratorX,
				numeratorY,
				numeratorXY;

	transvalues = check_float8_array(transarray, "float8_regr_r2", 6);
	N = transvalues[0];
	sumX = transvalues[1];
	sumX2 = transvalues[2];
	sumY = transvalues[3];
	sumY2 = transvalues[4];
	sumXY = transvalues[5];

	/* if N is 0 we should return NULL */
	if (N < 1.0)
		PG_RETURN_NULL();

	numeratorX = N * sumX2 - sumX * sumX;
	CHECKFLOATVAL(numeratorX, isinf(sumX2) || isinf(sumX), true);
	numeratorY = N * sumY2 - sumY * sumY;
	CHECKFLOATVAL(numeratorY, isinf(sumY2) || isinf(sumY), true);
	numeratorXY = N * sumXY - sumX * sumY;
	CHECKFLOATVAL(numeratorXY, isinf(sumXY) || isinf(sumX) ||
				  isinf(sumY), true);
	if (numeratorX <= 0)
		PG_RETURN_NULL();
	/* per spec, horizontal line produces 1.0 */
	if (numeratorY <= 0)
		PG_RETURN_FLOAT8(1.0);

	PG_RETURN_FLOAT8((numeratorXY * numeratorXY) /
					 (numeratorX * numeratorY));
}

Datum
float8_regr_slope(PG_FUNCTION_ARGS)
{
	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
	float8	   *transvalues;
	float8		N,
				sumX,
				sumX2,
				sumY,
				sumXY,
				numeratorX,
				numeratorXY;

	transvalues = check_float8_array(transarray, "float8_regr_slope", 6);
	N = transvalues[0];
	sumX = transvalues[1];
	sumX2 = transvalues[2];
	sumY = transvalues[3];
	sumXY = transvalues[5];

	/* if N is 0 we should return NULL */
	if (N < 1.0)
		PG_RETURN_NULL();

	numeratorX = N * sumX2 - sumX * sumX;
	CHECKFLOATVAL(numeratorX, isinf(sumX2) || isinf(sumX), true);
	numeratorXY = N * sumXY - sumX * sumY;
	CHECKFLOATVAL(numeratorXY, isinf(sumXY) || isinf(sumX) ||
				  isinf(sumY), true);
	if (numeratorX <= 0)
		PG_RETURN_NULL();

	PG_RETURN_FLOAT8(numeratorXY / numeratorX);
}

Datum
float8_regr_intercept(PG_FUNCTION_ARGS)
{
	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
	float8	   *transvalues;
	float8		N,
				sumX,
				sumX2,
				sumY,
				sumXY,
				numeratorX,
				numeratorXXY;

	transvalues = check_float8_array(transarray, "float8_regr_intercept", 6);
	N = transvalues[0];
	sumX = transvalues[1];
	sumX2 = transvalues[2];
	sumY = transvalues[3];
	sumXY = transvalues[5];

	/* if N is 0 we should return NULL */
	if (N < 1.0)
		PG_RETURN_NULL();

	numeratorX = N * sumX2 - sumX * sumX;
	CHECKFLOATVAL(numeratorX, isinf(sumX2) || isinf(sumX), true);
	numeratorXXY = sumY * sumX2 - sumX * sumXY;
	CHECKFLOATVAL(numeratorXXY, isinf(sumY) || isinf(sumX2) ||
				  isinf(sumX) || isinf(sumXY), true);
	if (numeratorX <= 0)
		PG_RETURN_NULL();

	PG_RETURN_FLOAT8(numeratorXXY / numeratorX);
}


/*
 *		====================================
 *		MIXED-PRECISION ARITHMETIC OPERATORS
 *		====================================
 */

/*
 *		float48pl		- returns arg1 + arg2
 *		float48mi		- returns arg1 - arg2
 *		float48mul		- returns arg1 * arg2
 *		float48div		- returns arg1 / arg2
 */
Datum
float48pl(PG_FUNCTION_ARGS)
{
	float4		arg1 = PG_GETARG_FLOAT4(0);
	float8		arg2 = PG_GETARG_FLOAT8(1);
	float8		result;

	result = arg1 + arg2;
	CHECKFLOATVAL(result, isinf(arg1) || isinf(arg2), true);
	PG_RETURN_FLOAT8(result);
}

Datum
float48mi(PG_FUNCTION_ARGS)
{
	float4		arg1 = PG_GETARG_FLOAT4(0);
	float8		arg2 = PG_GETARG_FLOAT8(1);
	float8		result;

	result = arg1 - arg2;
	CHECKFLOATVAL(result, isinf(arg1) || isinf(arg2), true);
	PG_RETURN_FLOAT8(result);
}

Datum
float48mul(PG_FUNCTION_ARGS)
{
	float4		arg1 = PG_GETARG_FLOAT4(0);
	float8		arg2 = PG_GETARG_FLOAT8(1);
	float8		result;

	result = arg1 * arg2;
	CHECKFLOATVAL(result, isinf(arg1) || isinf(arg2),
				  arg1 == 0 || arg2 == 0);
	PG_RETURN_FLOAT8(result);
}

Datum
float48div(PG_FUNCTION_ARGS)
{
	float4		arg1 = PG_GETARG_FLOAT4(0);
	float8		arg2 = PG_GETARG_FLOAT8(1);
	float8		result;

	if (arg2 == 0.0)
		ereport(ERROR,
				(errcode(ERRCODE_DIVISION_BY_ZERO),
				 errmsg("division by zero")));

	result = arg1 / arg2;
	CHECKFLOATVAL(result, isinf(arg1) || isinf(arg2), arg1 == 0);
	PG_RETURN_FLOAT8(result);
}

/*
 *		float84pl		- returns arg1 + arg2
 *		float84mi		- returns arg1 - arg2
 *		float84mul		- returns arg1 * arg2
 *		float84div		- returns arg1 / arg2
 */
Datum
float84pl(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float4		arg2 = PG_GETARG_FLOAT4(1);
	float8		result;

	result = arg1 + arg2;

	CHECKFLOATVAL(result, isinf(arg1) || isinf(arg2), true);
	PG_RETURN_FLOAT8(result);
}

Datum
float84mi(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float4		arg2 = PG_GETARG_FLOAT4(1);
	float8		result;

	result = arg1 - arg2;

	CHECKFLOATVAL(result, isinf(arg1) || isinf(arg2), true);
	PG_RETURN_FLOAT8(result);
}

Datum
float84mul(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float4		arg2 = PG_GETARG_FLOAT4(1);
	float8		result;

	result = arg1 * arg2;

	CHECKFLOATVAL(result, isinf(arg1) || isinf(arg2),
				  arg1 == 0 || arg2 == 0);
	PG_RETURN_FLOAT8(result);
}

Datum
float84div(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float4		arg2 = PG_GETARG_FLOAT4(1);
	float8		result;

	if (arg2 == 0.0)
		ereport(ERROR,
				(errcode(ERRCODE_DIVISION_BY_ZERO),
				 errmsg("division by zero")));

	result = arg1 / arg2;

	CHECKFLOATVAL(result, isinf(arg1) || isinf(arg2), arg1 == 0);
	PG_RETURN_FLOAT8(result);
}

/*
 *		====================
 *		COMPARISON OPERATORS
 *		====================
 */

/*
 *		float48{eq,ne,lt,le,gt,ge}		- float4/float8 comparison operations
 */
Datum
float48eq(PG_FUNCTION_ARGS)
{
	float4		arg1 = PG_GETARG_FLOAT4(0);
	float8		arg2 = PG_GETARG_FLOAT8(1);

	PG_RETURN_BOOL(float8_cmp_internal(arg1, arg2) == 0);
}

Datum
float48ne(PG_FUNCTION_ARGS)
{
	float4		arg1 = PG_GETARG_FLOAT4(0);
	float8		arg2 = PG_GETARG_FLOAT8(1);

	PG_RETURN_BOOL(float8_cmp_internal(arg1, arg2) != 0);
}

Datum
float48lt(PG_FUNCTION_ARGS)
{
	float4		arg1 = PG_GETARG_FLOAT4(0);
	float8		arg2 = PG_GETARG_FLOAT8(1);

	PG_RETURN_BOOL(float8_cmp_internal(arg1, arg2) < 0);
}

Datum
float48le(PG_FUNCTION_ARGS)
{
	float4		arg1 = PG_GETARG_FLOAT4(0);
	float8		arg2 = PG_GETARG_FLOAT8(1);

	PG_RETURN_BOOL(float8_cmp_internal(arg1, arg2) <= 0);
}

Datum
float48gt(PG_FUNCTION_ARGS)
{
	float4		arg1 = PG_GETARG_FLOAT4(0);
	float8		arg2 = PG_GETARG_FLOAT8(1);

	PG_RETURN_BOOL(float8_cmp_internal(arg1, arg2) > 0);
}

Datum
float48ge(PG_FUNCTION_ARGS)
{
	float4		arg1 = PG_GETARG_FLOAT4(0);
	float8		arg2 = PG_GETARG_FLOAT8(1);

	PG_RETURN_BOOL(float8_cmp_internal(arg1, arg2) >= 0);
}

/*
 *		float84{eq,ne,lt,le,gt,ge}		- float8/float4 comparison operations
 */
Datum
float84eq(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float4		arg2 = PG_GETARG_FLOAT4(1);

	PG_RETURN_BOOL(float8_cmp_internal(arg1, arg2) == 0);
}

Datum
float84ne(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float4		arg2 = PG_GETARG_FLOAT4(1);

	PG_RETURN_BOOL(float8_cmp_internal(arg1, arg2) != 0);
}

Datum
float84lt(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float4		arg2 = PG_GETARG_FLOAT4(1);

	PG_RETURN_BOOL(float8_cmp_internal(arg1, arg2) < 0);
}

Datum
float84le(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float4		arg2 = PG_GETARG_FLOAT4(1);

	PG_RETURN_BOOL(float8_cmp_internal(arg1, arg2) <= 0);
}

Datum
float84gt(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float4		arg2 = PG_GETARG_FLOAT4(1);

	PG_RETURN_BOOL(float8_cmp_internal(arg1, arg2) > 0);
}

Datum
float84ge(PG_FUNCTION_ARGS)
{
	float8		arg1 = PG_GETARG_FLOAT8(0);
	float4		arg2 = PG_GETARG_FLOAT4(1);

	PG_RETURN_BOOL(float8_cmp_internal(arg1, arg2) >= 0);
}

/*
 * Implements the float8 version of the width_bucket() function
 * defined by SQL2003. See also width_bucket_numeric().
 *
 * 'bound1' and 'bound2' are the lower and upper bounds of the
 * histogram's range, respectively. 'count' is the number of buckets
 * in the histogram. width_bucket() returns an integer indicating the
 * bucket number that 'operand' belongs to in an equiwidth histogram
 * with the specified characteristics. An operand smaller than the
 * lower bound is assigned to bucket 0. An operand greater than the
 * upper bound is assigned to an additional bucket (with number
 * count+1). We don't allow "NaN" for any of the float8 inputs, and we
 * don't allow either of the histogram bounds to be +/- infinity.
 */
Datum
width_bucket_float8(PG_FUNCTION_ARGS)
{
	float8		operand = PG_GETARG_FLOAT8(0);
	float8		bound1 = PG_GETARG_FLOAT8(1);
	float8		bound2 = PG_GETARG_FLOAT8(2);
	int32		count = PG_GETARG_INT32(3);
	int32		result;

	if (count <= 0.0)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION),
				 errmsg("count must be greater than zero")));

	if (isnan(operand) || isnan(bound1) || isnan(bound2))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION),
			  errmsg("operand, lower bound and upper bound cannot be NaN")));

	/* Note that we allow "operand" to be infinite */
	if (is_infinite(bound1) || is_infinite(bound2))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION),
				 errmsg("lower and upper bounds must be finite")));

	if (bound1 < bound2)
	{
		if (operand < bound1)
			result = 0;
		else if (operand >= bound2)
		{
			result = count + 1;
			/* check for overflow */
			if (result < count)
				ereport(ERROR,
						(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
						 errmsg("integer out of range")));
		}
		else
			result = ((float8) count * (operand - bound1) / (bound2 - bound1)) + 1;
	}
	else if (bound1 > bound2)
	{
		if (operand > bound1)
			result = 0;
		else if (operand <= bound2)
		{
			result = count + 1;
			/* check for overflow */
			if (result < count)
				ereport(ERROR,
						(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
						 errmsg("integer out of range")));
		}
		else
			result = ((float8) count * (bound1 - operand) / (bound1 - bound2)) + 1;
	}
	else
	{
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION),
				 errmsg("lower bound cannot equal upper bound")));
		result = 0;				/* keep the compiler quiet */
	}

	PG_RETURN_INT32(result);
}

/* ========== PRIVATE ROUTINES ========== */

#ifndef HAVE_CBRT

static double
cbrt(double x)
{
	int			isneg = (x < 0.0);
	double		absx = fabs(x);
	double		tmpres = pow(absx, (double) 1.0 / (double) 3.0);

	/*
	 * The result is somewhat inaccurate --- not really pow()'s fault, as the
	 * exponent it's handed contains roundoff error.  We can improve the
	 * accuracy by doing one iteration of Newton's formula.  Beware of zero
	 * input however.
	 */
	if (tmpres > 0.0)
		tmpres -= (tmpres - absx / (tmpres * tmpres)) / (double) 3.0;

	return isneg ? -tmpres : tmpres;
}

#endif   /* !HAVE_CBRT */