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authorEthan Werner <mail@ethanwerner.com>2026-08-09 15:02:21 +0400
committerEthan Werner <mail@ethanwerner.com>2026-08-09 15:02:21 +0400
commit3d92926a902017e7cf1f5738e99ff62da596ce12 (patch)
tree2b55422c26a48759d56fa91f06df24449e9dfa88 /lib/bollinger_bands.c
parent07e18043145f3d91c8ea7ec3ad41b3c905585277 (diff)
Diffstat (limited to 'lib/bollinger_bands.c')
-rw-r--r--lib/bollinger_bands.c23
1 files changed, 15 insertions, 8 deletions
diff --git a/lib/bollinger_bands.c b/lib/bollinger_bands.c
index 55da054..56ce8f9 100644
--- a/lib/bollinger_bands.c
+++ b/lib/bollinger_bands.c
@@ -25,7 +25,7 @@ ts_parameter_t const ts_bollinger_bands_p = { .n_inputs = 1, .n_outputs = 3, .n_
uint_t ts_bollinger_bands_offset( ts_constant_t const *c )
{
( void )c;
- return ( c ? ((ts_bollinger_bands_params_t *)c)->k - 1 : 0 );
+ return ( c ? ((ts_bollinger_bands_params_t const *)c)->k > 0 ? ((ts_bollinger_bands_params_t const *)c)->k - 1 : 0 : 0 );
}
int ts_bollinger_bands(
@@ -37,10 +37,17 @@ int ts_bollinger_bands(
TS_PROLOGUE( ts_bollinger_bands_p );
if ( !c ) return -1;
TS_CHECK_INPUT(x, x_n, n);
- uint_t k = ((ts_bollinger_bands_params_t *)c)->k;
+ uint_t k = ((ts_bollinger_bands_params_t const *)c)->k;
if (k == 0 || n < k) return -1;
- fp_t std_mult = ((ts_bollinger_bands_params_t *)c)->std_mult;
- if (std_mult < 0 || isnan(std_mult)) return -1;
+ fp_t std_mult = ((ts_bollinger_bands_params_t const *)c)->std_mult;
+ if (std_mult < 0 || isnan(std_mult) || isinf(std_mult)) return -1;
+
+ for( uint_t i = 0; i < k - 1; ++i )
+ {
+ y[0][i] = NAN;
+ y[1][i] = NAN;
+ y[2][i] = NAN;
+ }
// Two-pass initial window for numerical stability
{
@@ -56,8 +63,8 @@ int ts_bollinger_bands(
}
variance /= (fp_t)k;
fp_t stddev = sqrt( variance );
- y[1][k - 1] = mean + std_mult * stddev;
- y[0][k - 1] = mean;
+ y[0][k - 1] = mean + std_mult * stddev;
+ y[1][k - 1] = mean;
y[2][k - 1] = mean - std_mult * stddev;
}
@@ -79,8 +86,8 @@ int ts_bollinger_bands(
}
variance *= rk;
fp_t stddev = sqrt( variance );
- y[1][i] = mean + std_mult * stddev;
- y[0][i] = mean;
+ y[0][i] = mean + std_mult * stddev;
+ y[1][i] = mean;
y[2][i] = mean - std_mult * stddev;
}
return 0;