source: добавление функции создания гистограммы в SVG

histogram.cpp

@@ -1,4 +1,5 @@
 #include "histogram.h"
+#include "svg.h"
 using namespace std;
 
 //  Ïîèñê ìàêñèìóìà è ìèíèìóìà ñðåäè îöåíîê.
@@ -52,3 +53,38 @@ vector<size_t> make_histogram(const vector<double>& numbers, size_t bin_count)
         }
     return bins;
 }
+
+//  Ñîçäàíèå ãèñòîãðàììû íà îñíîâàíèè êîðçèí â ôîðìàòå SVG.
+
+void show_histogram_svg(const vector<size_t>& bins)
+{
+//  Íåîáõîäèìûå êîíñòàíòû.
+    const auto IMAGE_WIDTH = 400;
+    const auto IMAGE_HEIGHT = 300;
+    const auto TEXT_LEFT = 20;
+    const auto TEXT_BASELINE = 20;
+    const auto TEXT_WIDTH = 50;
+    const auto BIN_HEIGHT = 30;
+    size_t max_bins = bins[0];
+
+//  Ïîèñê ìàêñèìàëüíîé êîðçèíû.
+
+    for (size_t x: bins)
+        if (x > max_bins)
+            max_bins = x;
+
+//  Âûðàâíèâàíèå ãèñòîãðàììû ïî ìàêñèìàëüíîìó ñòîëáöó.
+
+    const auto BLOCK_WIDTH = (IMAGE_WIDTH - TEXT_WIDTH)/max_bins;//BLOCK_WIDTH = 10
+
+    svg_begin(IMAGE_WIDTH, IMAGE_HEIGHT);
+    double top = 0;
+    for (size_t bin : bins)
+        {
+            const double bin_width = BLOCK_WIDTH * bin;
+            svg_text(TEXT_LEFT, top + TEXT_BASELINE, to_string(bin));
+            svg_rect(TEXT_WIDTH, top, bin_width, BIN_HEIGHT);
+            top += BIN_HEIGHT;
+        }
+    svg_end();
+}