#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include "ts.h"


fp_t * ts_fill( fp_t *x, uint_t n, fp_t x0, fp_t x1 )
{
	if ( !x || n == 0 ) return x;

	fp_t step = n > 1 ? ( x1 - x0 ) / ( fp_t )( n - 1 ) : 0.0;

	if( fabs( x0 ) < TS_FILL_ZERO_THRESHOLD && fabs( x1 ) < TS_FILL_ZERO_THRESHOLD )
	{
		memset( x, 0, sizeof( fp_t ) * n );
	}
	else
	{
		for( uint_t i = 0; i < n; i++ )
		{
			x[i] = x0 + ( (fp_t)i * step );
		}
	}

	return x;
}


void ts_print( fp_t const *x, uint_t n, FILE *stream )
{
	if ( !x || n == 0 ) return;

	FILE *out = stream ? stream : stdout;

	fputc( '[', out );

	for ( uint_t i = 0; i < n - 1; i++ )
	{
		fprintf( out, "%f,", x[i] );
	}

	fprintf( out, "%f]", x[n - 1] );
}


void ts_pretty_print( fp_t const * const *x, uint_t m, uint_t n, FILE *stream )
{
	if ( !x || m == 0 || n == 0 ) return;

	FILE *out = stream ? stream : stdout;

	if( m > 1 )
	{
		for( uint_t i = 0; i < n; i++ )
		{
			for( uint_t j = 0; j < m; j++ )
			{
				fprintf( out, "%f  ", x[j][i] );
			}

			fputs( "\n", out );
		}
	}
	else
	{
		for( uint_t i = 0; i < n; i++ )
		{
			fprintf( out, "%f\n", x[0][i] );
		}
	}
}


fp_t _ts_square( fp_t x )
{
    return x * x;
}


fp_t _ts_reciprocal( fp_t x )
{
    return x != 0 ? 1.0 / x : INFINITY;
}


fp_t _ts_square_pyramidal_number( fp_t x )
{
    return ( x * ( x + 1 ) * ( 2 * x + 1 ) ) / 6;
}


fp_t _ts_triangle_number( fp_t x )
{
    return ( ( x ) * ( ( x ) + 1 ) ) * 0.5;
}


fp_t _ts_sum_to_covariance( fp_t sum_xy, fp_t sum_x, fp_t sum_y, uint_t k )
{
    if ( k == 0 ) return 0.0;
    return ( sum_xy - ( sum_x * sum_y / k ) ) / k;
}


fp_t _ts_sum_to_variance( fp_t sum_x2, fp_t sum_x, uint_t k )
{
    return fmax( 0.0, _ts_sum_to_covariance( sum_x2, sum_x, sum_x, k ) );
}


uint_t _ts_circle_increment( uint_t i, uint_t k )
{
    if ( k == 0 ) return i;
    return ( i + 1 ) % k;
}