From 6fb519761f5f942e598cfd8570c52594c9456ba3 Mon Sep 17 00:00:00 2001 From: John Darrington Date: Mon, 15 Sep 2008 11:42:43 +0800 Subject: [PATCH] Added some error checking to casereader_create_append_rank Thanks to Ben Pfaff for this suggestion. --- src/data/casereader-translator.c | 48 ++++++++++++++++++++++++++------ src/data/casereader.h | 8 ++++++ 2 files changed, 48 insertions(+), 8 deletions(-) diff --git a/src/data/casereader-translator.c b/src/data/casereader-translator.c index 14fcd9ab..ae22f129 100644 --- a/src/data/casereader-translator.c +++ b/src/data/casereader-translator.c @@ -17,7 +17,6 @@ #include #include #include -#include #include #include @@ -131,7 +130,7 @@ static void can_translate (struct ccase *input, struct ccase *output, by reading from SUBREADER and appending an additional value, generated by FUNC. AUX is an optional parameter which gets passed to FUNC. FUNC will also receive N as it, which is - the ordinal number of the case in the reader. DESTROY is an + the ordinal number of the case in the reader. DESTROY is an optional parameter used to destroy AUX. After this function is called, SUBREADER must not ever again @@ -226,6 +225,8 @@ struct casereader_append_rank double cc; distinct_func *distinct; void *aux; + enum rank_error *err; + double prev_value; }; static bool car_destroy (void *car_); @@ -235,9 +236,19 @@ static void car_translate (struct ccase *input, struct ccase *output, /* Creates and returns a new casereader whose cases are produced by reading from SUBREADER and appending an additional value, - which is the rank of the observation. SUBREADER must be sorted - on V. W is the weight variable of the dictionary containing V, - or NULL if there is no weight variable. + which is the rank of the observation. W is the weight variable + of the dictionary containing V, or NULL if there is no weight + variable. + + The following preconditions must be met: + + 1. SUBREADER must be sorted on V. + + 2. The weight variables, must be non-negative. + + If either of these preconditions are not satisfied, then the rank + variables may not be correct. In this case, if ERR is non-null, + it will be set according to the erroneous conditions encountered. If DISTINCT_CALLBACK is non-null, then it will be called exactly once for every case containing a distinct value of V. AUX is @@ -250,6 +261,7 @@ struct casereader * casereader_create_append_rank (struct casereader *subreader, const struct variable *v, const struct variable *w, + enum rank_error *err, distinct_func *distinct_callback, void *aux ) @@ -264,6 +276,8 @@ casereader_create_append_rank (struct casereader *subreader, car->clone = casereader_clone (subreader); car->distinct = distinct_callback; car->aux = aux; + car->err = err; + car->prev_value = SYSMIS; return casereader_create_translator (subreader, car->value_ofs + 1, car_translate, car_destroy, car); @@ -285,7 +299,13 @@ car_translate (struct ccase *input, struct ccase *output, void *car_) { struct casereader_append_rank *car = car_; - double value = case_data (input, car->var)->f; + const double value = case_data (input, car->var)->f; + + if ( car->prev_value != SYSMIS) + { + if (car->err && value < car->prev_value) + *car->err |= RANK_ERR_UNSORTED; + } if ( car->n_common == 1) { @@ -293,7 +313,11 @@ car_translate (struct ccase *input, struct ccase *output, void *car_) casenumber k = 0; double weight = 1.0; if (car->weight) - weight = case_data (input, car->weight)->f; + { + weight = case_data (input, car->weight)->f; + if ( car->err && weight < 0 ) + *car->err |= RANK_ERR_NEGATIVE_WEIGHT; + } do { @@ -305,7 +329,14 @@ car_translate (struct ccase *input, struct ccase *output, void *car_) if ( vxx == value) { if (car->weight) - weight += case_data (&c, car->weight)->f; + { + double w = case_data (&c, car->weight)->f; + + if ( car->err && w < 0 ) + *car->err |= RANK_ERR_NEGATIVE_WEIGHT; + + weight += w; + } else weight += 1.0; car->n_common++; @@ -328,6 +359,7 @@ car_translate (struct ccase *input, struct ccase *output, void *car_) case_move (output, input); case_resize (output, car->value_ofs + 1); case_data_rw_idx (output, car->value_ofs)->f = car->mean_rank ; + car->prev_value = value; } diff --git a/src/data/casereader.h b/src/data/casereader.h index a2d9403b..3df80cb0 100644 --- a/src/data/casereader.h +++ b/src/data/casereader.h @@ -125,12 +125,20 @@ struct casereader * casereader_create_arithmetic_sequence (struct casereader *, double first, double increment); +enum rank_error + { + RANK_ERR_NONE = 0, + RANK_ERR_NEGATIVE_WEIGHT = 0x01, + RANK_ERR_UNSORTED = 0x02 + }; + typedef void distinct_func (double v, casenumber n, double w, void *aux); struct casereader * casereader_create_append_rank (struct casereader *, const struct variable *v, const struct variable *w, + enum rank_error *err, distinct_func *distinct_callback, void *aux); -- 2.30.2