Heat map optimisation

Programming Questions

tomschofi..

in Programming Questions • 1 year ago

Hi guys,

I wrote the below heat mapping function. It works reasonably well but sometimes gives me an out of memory error. I wonder is anyone has any suggestions for optimisation. I'm also controlling the fall off of the points a bit brutally with a multiplier (called fallOff). I wonder if this should also be some kind of logarithmic function? Cheers folks, hopefully this thread will expand a bit and we can get good solid simple solution!

cheers

Tom

PImage makeHeatMap(PVector [] dataPoints, float fallOff) {

PImage timg=createImage(width, height, RGB);

timg.loadPixels();

loadPixels();

dataPoints[0].x=mouseX;

dataPoints[0].y=mouseY;

//maxpossible distance between any 2 pixels is the diagonal distance across the screen

float maxDist = sqrt((width*width)+(height*height));

float heats[] =new float[pixels.length];

int x=0;

int y=0;

for (int i=0;i<pixels.length;i++) {

//get average distance to all points

float averageDistance=0.0f;

for (int j=0;j< dataPoints.length;j++) {

float thisDist=dist(x, y, dataPoints[j].x, dataPoints[j].y) ;

//multiply the distance by the scaler

averageDistance+=thisDist*dataPoints[j].z;

//float _hue =(1.0f/7.0f)* map(sqrt(thisDist), 0, sqrt(maxDist), 0, 255);

}

averageDistance/=dataPoints.length;

float _hue = map (sqrt(averageDistance), 0, sqrt(maxDist)*fallOff, 0, 255);

timg.pixels[i]= color(_hue, 255, 255);

x++;

if (x>=width) {

x=0;

y++;

}

timg.updatePixels();

return timg;

}

Replies(3)

cedrickie..

Re: Heat map optimisation

1 year ago

would be great if you could share the whole code. or at least a running version. otherwise its quite hard to see where the problem is without testing.

tomschofi..

Re: Heat map optimisation

1 year ago

Hi cedrickie,

thanks for your help. Whole sketch below (requires controlP5)

import controlP5.*;

PImage mapImage;

PFont font;

PVector [] _pointers;

float _fallOff = 1.55;

ControlP5 cp5;

void setup() {

size(800, 600);

colorMode(HSB);

font =loadFont("AppleBraille-14.vlw");

textFont (font,14);

_pointers=new PVector[7];

for (int i=0;i<_pointers.length;i++) {

_pointers[i]=new PVector(random(width), random(height), random(10.0));

}

//mapImage=makeImage();

cp5 = new ControlP5(this);

cp5.addSlider("_fallOff").setPosition(100, 50).setRange(0.0, 2.0);

}

void draw() {

mapImage=makeHeatMap(_pointers,_fallOff);

image(mapImage, 0, 0);

for (int i=0;i<_pointers.length;i++) {

text(str(_pointers[i].z),_pointers[i].x, _pointers[i].y);

}

PImage makeHeatMap(PVector [] dataPoints, float fallOff) {

PImage timg=createImage(width, height, RGB);

timg.loadPixels();

loadPixels();

dataPoints[0].x=mouseX;

dataPoints[0].y=mouseY;

//maxpossible distance between any 2 pixels is the diagonal distance across the screen

float maxDist = sqrt((width*width)+(height*height));

float heats[] =new float[pixels.length];

int x=0;

int y=0;

for (int i=0;i<pixels.length;i++) {

//get average distance to all points

float averageDistance=0.0f;

for (int j=0;j< dataPoints.length;j++) {

float thisDist=dist(x, y, dataPoints[j].x, dataPoints[j].y) ;

//multiply the distance by the scaler

averageDistance+=thisDist*dataPoints[j].z;

//float _hue =(1.0f/7.0f)* map(sqrt(thisDist), 0, sqrt(maxDist), 0, 255);

}

averageDistance/=dataPoints.length;

float _hue = map (sqrt(averageDistance), 0, sqrt(maxDist)*fallOff, 0, 255);

timg.pixels[i]= color(_hue, 255, 255);

x++;

if (x>=width) {

x=0;

y++;

}

timg.updatePixels();

return timg;

}

void controlEvent(ControlEvent theEvent) {

}

tomschofi..

Re: Heat map optimisation SOLVED

11 months ago

Hi All

I found a good solution (I think to this problem). I posted it here

Tom

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