Fixes #3,#11,#12,#15 resolves #2,#14,#23 couple of perfomance tweaks

.coveragerc

@@ -0,0 +1,3 @@
+[run]
+branch=True 
+include=*heatmap*

.gitignore

@@ -31,6 +31,7 @@ pip-log.txt
 .coverage
 .tox
 nosetests.xml
+/htmlcov
 
 # Translations
 *.mo
@@ -44,4 +45,4 @@ nosetests.xml
 .DS_Store
 
 *.png
-*.kml
+*.kml

.travis.yml

@@ -1,6 +1,10 @@
 language: python
 python:
+  - "2.6"
   - "2.7"
+  - "3.2"
+  - "3.3"
+  - "3.4"
 
 # command to install dependencies
 install: 

examples/example.py

@@ -5,6 +5,6 @@
     pts = []
     for x in range(400):
         pts.append((random.random(), random.random()))
-    print "Processing %d points..." % len(pts)
+    print("Processing %d points..." % len(pts))
     hm = heatmap.Heatmap()
     img = hm.heatmap(pts).save("classic.png")

heatmap/__init__.py

@@ -1,6 +1,6 @@
 try:
     __version__ = __import__('pkg_resources').get_distribution(__name__).version
-except Exception, e:
+except Exception as e:
     __version__ = 'unknown'
 
-from heatmap import Heatmap
+from .heatmap import Heatmap

heatmap/heatmap.c

@@ -3,6 +3,9 @@
 #include <math.h>
 #include <string.h>
 
+float constant = 50.0;
+float multiplier = 200.0;
+
 struct info
 {
 	float minX;
@@ -12,6 +15,7 @@ struct info
 
 	int width;
 	int height;
+        int cPixels;
 	int dotsize;
 };
 
@@ -33,7 +37,7 @@ BOOL WINAPI DllMain(    HINSTANCE hinstDLL,  // handle to DLL module
 #endif
 
 //walk the list of points, get the boundary values    
-void getBounds(struct info *inf, float *points, unsigned int cPoints)
+void getBounds(struct info *inf, float *points, unsigned int cPoints, int weighted)
 {
     unsigned int i = 0;
 
@@ -43,8 +47,11 @@ void getBounds(struct info *inf, float *points, unsigned int cPoints)
     float maxX = points[i];
     float maxY = points[i+1];
 
+    int inc = 2;
+    if (weighted) inc = 3;
+
     //then iterate over the list and find the max/min values
-    for(i = 0; i < cPoints; i=i+2)
+    for(i = 0; i < cPoints; i=i+inc)
     {
         float x = points[i];
         float y = points[i+1];
@@ -86,31 +93,36 @@ struct point translate(struct info *inf, struct point pt)
     return pt;
 }
 
-unsigned char* calcDensity(struct info *inf, float *points, int cPoints)
+unsigned char* calcDensity(struct info *inf, float *points, int cPoints, int weighted)
 {
     int width = inf->width;
     int height = inf->height;
+    int cPixels = inf->cPixels;
     int dotsize = inf->dotsize;
 
-    unsigned char* pixels = (unsigned char *)calloc(width*height, sizeof(char)); 
+    unsigned char* pixels = (unsigned char *)malloc(cPixels*sizeof(char)); 
 
     float midpt = dotsize / 2.f;
-    double radius = sqrt(midpt*midpt + midpt*midpt) / 2.f;
-    double dist = 0.0;
+    float radius = sqrt(midpt*midpt + midpt*midpt) / 2.f;
+    float dist = 0.0;
     int pixVal = 0;
     int j = 0;
     int k = 0;
     int i = 0;
     int ndx = 0;
     struct point pt = {0};  
 
+    int inc = 2;
+    if (weighted) inc = 3;
+
     // initialize image data to white
-    for(i = 0; i < (int)width*height; i++) 
+    for(i = 0; i < cPixels; i++) 
     {
         pixels[i] = 0xff;
     }
 
-    for(i = 0; i < cPoints; i=i+2)
+
+    for(i = 0; i < cPoints; i=i+inc)
     {
         pt.x = points[i];
         pt.y = points[i+1];
@@ -123,12 +135,21 @@ unsigned char* calcDensity(struct info *inf, float *points, int cPoints)
                 if (j < 0 || k < 0 || j >= width || k >= height) continue; 
 
                 dist = sqrt( (j-pt.x)*(j-pt.x) + (k-pt.y)*(k-pt.y) );
-
-                pixVal = (int)(200.0*(dist/radius)+50.0);
-                if (pixVal > 255) pixVal = 255;
+
+                if(dist>radius) continue; // stop point contributing to pixels outside its radius
 
                 ndx = k*width + j;
-                if(ndx >= (int)width*height) continue;   // ndx can be greater than array bounds
+                if(ndx >= cPixels) continue;   // ndx can be greater than array bounds
+
+                if(weighted)
+                {
+                  pixVal = (int)((multiplier*(dist/radius)+constant)/points[i+2]);
+                }
+                else
+                {
+                  pixVal = (int)(multiplier*(dist/radius)+constant);
+                }
+                if (pixVal > 255) pixVal = 255;
 
                 #ifdef DEBUG
                 printf("pt.x: %.2f pt.y: %.2f j: %d k: %d ndx: %d\n", pt.x, pt.y, j, k, ndx);
@@ -145,16 +166,14 @@ unsigned char* calcDensity(struct info *inf, float *points, int cPoints)
 unsigned char *colorize(struct info *inf, unsigned char* pixels_bw, int *scheme, unsigned char* pixels_color, 
               int opacity)
 {
-    int width = inf->width;
-    int height = inf->height;
-    int dotsize = inf->dotsize;
+    int cPixels = inf->cPixels;
 
     int i = 0;
     int pix = 0;
     int highCount = 0;
     int alpha = opacity;
 
-    for(i = 0; i < (int)width*height; i++)
+    for(i = 0; i < cPixels; i++)
     {
         pix = pixels_bw[i];
 
@@ -170,7 +189,7 @@ unsigned char *colorize(struct info *inf, unsigned char* pixels_bw, int *scheme,
         pixels_color[i*4+3] = alpha;
     } 
 
-    if (highCount > width*height*0.8)
+    if (highCount > cPixels*0.8)
     {   
         fprintf(stderr, "Warning: 80%% of output pixels are over 95%% density.\n");
         fprintf(stderr, "Decrease dotsize or increase output image resolution?\n");
@@ -190,23 +209,24 @@ unsigned char *tx(float *points,
                   unsigned char *pix_color, 
                   int opacity, 
                   int boundsOverride, 
-                  float minX, float minY, float maxX, float maxY)
+                  float minX, float minY, float maxX, float maxY, int weighted)
 {
     unsigned char *pixels_bw = NULL;
+    struct info inf = {0};
 
     //basic sanity checks to keep from segfaulting
     if (NULL == points || NULL == scheme || NULL == pix_color ||
-        w <= 0 || h <= 0 || cPoints <= 1 || opacity < 0 || dotsize <= 0)
+        w <= 0 || h <= 0 || cPoints <= 1+weighted || cPoints % (2+weighted) != 0 ||
+        opacity < 0 || opacity > 255 || dotsize <= 0)
     {
         fprintf(stderr, "Invalid parameter; aborting.\n");
         return NULL;
     }
 
-    struct info inf = {0};
-
     inf.dotsize = dotsize;
     inf.width = w;
     inf.height = h;
+    inf.cPixels = w*h;
 
     // get min/max x/y values from point list
     if (boundsOverride == 1)
@@ -216,7 +236,7 @@ unsigned char *tx(float *points,
     }
     else
     {
-        getBounds(&inf, points, cPoints);
+        getBounds(&inf, points, cPoints, weighted);
     }
 
     #ifdef DEBUG
@@ -225,7 +245,7 @@ unsigned char *tx(float *points,
 
     //iterate through points, place a dot at each center point
     //and set pix value from 0 - 255 using multiply method for radius [dotsize].
-    pixels_bw = calcDensity(&inf, points, cPoints);
+    pixels_bw = calcDensity(&inf, points, cPoints, weighted);
 
     //using provided color scheme and opacity, update pixel value to RGBA values
     pix_color = colorize(&inf, pixels_bw, scheme, pix_color, opacity);