/********************************************************************** * File: statistc.h (Formerly stats.h) * Description: Class description for STATS class. * Author: Ray Smith * Created: Mon Feb 04 16:19:07 GMT 1991 * * (C) Copyright 1991, Hewlett-Packard Ltd. ** Licensed under the Apache License, Version 2.0 (the "License"); ** you may not use this file except in compliance with the License. ** You may obtain a copy of the License at ** http://www.apache.org/licenses/LICENSE-2.0 ** Unless required by applicable law or agreed to in writing, software ** distributed under the License is distributed on an "AS IS" BASIS, ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ** See the License for the specific language governing permissions and ** limitations under the License. * **********************************************************************/ #ifndef TESSERACT_CCSTRUCT_STATISTC_H_ #define TESSERACT_CCSTRUCT_STATISTC_H_ #include #include "host.h" #include "scrollview.h" // Simple histogram-based statistics for integer values in a known // range, such that the range is small compared to the number of samples. class STATS { public: // The histogram buckets are in the range // [min_bucket_value, max_bucket_value_plus_1 - 1] i.e. // [min_bucket_value, max_bucket_value]. // Any data under min_bucket value is silently mapped to min_bucket_value, // and likewise, any data over max_bucket_value is silently mapped to // max_bucket_value. // In the internal array, min_bucket_value maps to 0 and // max_bucket_value_plus_1 - min_bucket_value to the array size. // TODO(rays) This is ugly. Convert the second argument to // max_bucket_value and all the code that uses it. STATS(inT32 min_bucket_value, inT32 max_bucket_value_plus_1); STATS(); // empty for arrays ~STATS(); // (Re)Sets the range and clears the counts. // See the constructor for info on max and min values. bool set_range(inT32 min_bucket_value, inT32 max_bucket_value_plus_1); void clear(); // empty buckets void add(inT32 value, inT32 count); // "Accessors" return various statistics on the data. inT32 mode() const; // get mode of samples double mean() const; // get mean of samples double sd() const; // standard deviation // Returns the fractile value such that frac fraction (in [0,1]) of samples // has a value less than the return value. double ile(double frac) const; // Returns the minimum used entry in the histogram (ie the minimum of the // data, NOT the minimum of the supplied range, nor is it an index.) // Would normally be called min(), but that is a reserved word in VC++. inT32 min_bucket() const; // Find min // Returns the maximum used entry in the histogram (ie the maximum of the // data, NOT the maximum of the supplied range, nor is it an index.) inT32 max_bucket() const; // Find max // Finds a more useful estimate of median than ile(0.5). // Overcomes a problem with ile() - if the samples are, for example, // 6,6,13,14 ile(0.5) return 7.0 - when a more useful value would be midway // between 6 and 13 = 9.5 double median() const; // get median of samples // Returns the count of the given value. inT32 pile_count(inT32 value ) const { if (value <= rangemin_) return buckets_[0]; if (value >= rangemax_ - 1) return buckets_[rangemax_ - rangemin_ - 1]; return buckets_[value - rangemin_]; } // Returns the total count of all buckets. inT32 get_total() const { return total_count_; // total of all piles } // Returns true if x is a local min. bool local_min(inT32 x) const; // Apply a triangular smoothing filter to the stats. // This makes the modes a bit more useful. // The factor gives the height of the triangle, i.e. the weight of the // centre. void smooth(inT32 factor); // Cluster the samples into max_cluster clusters. // Each call runs one iteration. The array of clusters must be // max_clusters+1 in size as cluster 0 is used to indicate which samples // have been used. // The return value is the current number of clusters. inT32 cluster(float lower, // thresholds float upper, float multiple, // distance threshold inT32 max_clusters, // max no to make STATS *clusters); // array of clusters // Prints a summary and table of the histogram. void print() const; // Prints summary stats only of the histogram. void print_summary() const; #ifndef GRAPHICS_DISABLED // Draws the histogram as a series of rectangles. void plot(ScrollView* window, // window to draw in float xorigin, // origin of histo float yorigin, // gram float xscale, // size of one unit float yscale, // size of one uint ScrollView::Color colour) const; // colour to draw in // Draws a line graph of the histogram. void plotline(ScrollView* window, // window to draw in float xorigin, // origin of histo float yorigin, // gram float xscale, // size of one unit float yscale, // size of one uint ScrollView::Color colour) const; // colour to draw in #endif // GRAPHICS_DISABLED private: inT32 rangemin_; // min of range // rangemax_ is not well named as it is really one past the max. inT32 rangemax_; // max of range inT32 total_count_; // no of samples inT32* buckets_; // array of cells }; // Returns the nth ordered item from the array, as if they were // ordered, but without ordering them, in linear time. // The array does get shuffled! inT32 choose_nth_item(inT32 index, // index to choose float *array, // array of items inT32 count); // no of items // Generic version uses a defined comparator (with qsort semantics). inT32 choose_nth_item(inT32 index, // index to choose void *array, // array of items inT32 count, // no of items size_t size, // element size int (*compar)(const void*, const void*)); // comparator // Swaps 2 entries in an array in-place. void swap_entries(void *array, // array of entries size_t size, // size of entry inT32 index1, // entries to swap inT32 index2); #endif // TESSERACT_CCSTRUCT_STATISTC_H_