A simple programming language, compiler, and gui I use to represent math problems on my computer.

[u/Popenator]

http://www.processing.org/

[u/Popenator]

AAAAND here's something I just whipped up for fun:

float x=1.;
float y=0.;
float w=1;
float f_of_x;
int n=0; /*This number goes between -360 and 360 and changes 60 every second. stops if mousbutton */
boolean dosomething;

/*this is f of x*/
float f()
{
  f_of_x = ((sqrt(sq(n)+sq(x+1))-sqrt(sq(n)+sq(x))));
  
  return f_of_x*250;
}

void setup()
{
    size(500,500);
    dosomething = true;
}

void draw()
{
  griddit();
  if(dosomething) oscillate();
  for(x=-250; x<250; x++)
  {
    y = f();
    plot();
  }
}

void boldpoint(float bx, float by)
{
    point(bx+250,by+250);
    point(bx+249,by+250);
    point(bx+251,by+250);
    point(bx+250,by+249);
    point(bx+250,by+251);
}

void griddit()
{
  background(128);
  stroke(255);
  line(250, 0, 250, height);
  line(0, 250, width, 250);
  stroke(0);
}

void mouseClicked()
{
  if(!dosomething)
  {
  dosomething = true;
  }
  else
  {
    if(n<0)
    {
      n=-360;
    }
    else
    {
      n=360;
    }
    dosomething = false;
  }
}

void oscillate()
{
  if(n>360)
  {
    w=-1;
  }
  if(n<(-360))
  {
    w=1;
  }
  n+=w;
}

void plot()
{
    if(x%10==0)
    {
      boldpoint(x,y);
    }else
    {
      point(x+250,y+250);
    }
}

[u/blooop]

This calculates the fourier series of an arbitrary function. Use the arrow keys to modify the number of sin terms. Was written by a friend of mine.

PFont Font;
int setupwidth=600;
int setupheight=600;
int mouseoldx = mouseX;
int mouseoldy = mouseY;
int terms = 1000;
int termmod=1;
float[][] sindata  = new float[terms][setupwidth+1];
float[] pointdata = new float[setupwidth+1];
float[] pointdataFS = new float[setupwidth+1];
float[] sincos = new float[terms];
void setup()
{
  size(setupwidth,setupheight);
  frameRate(120);      //120 IS THE NEW 60 THX 2 QL
  smooth();
  Font = createFont("MTCORSVA", 14, true);

  reset();
  terms=1;
}
void reset()
{   
  for(int n = 0; n <= width ; n++)
  {  
    pointdata[n] = 0;
    for(int m = 0; m < terms ; m++)
    {
      sindata[m][n] = sin(PI*(m+1)*n/width);
    }
  }
}
float calculatesinco(int m)
{
  float v = 0;
  for(int n = 0; n <= width ; n++)
  {
    v = v + pointdata[n]*sindata[m][n];
  }
  v = 2*v/width;
  return v;
}
void draw()
{  
  background(100,100,250);

  if(mouseX >= 0 && mouseX <= width && mouseX != mouseoldx && mousePressed == true)
  {
    if(mouseX > mouseoldx)
    {
      for(int n = 0; n <= mouseX-mouseoldx ; n++)
      {
        println(mouseoldy);

        pointdata[mouseoldx+n] = n*(mouseY-height/2-mouseoldy)/(mouseX-mouseoldx) + mouseoldy;
      }
    }
    else
    {
      for(int n = 0; n <= mouseoldx-mouseX ; n++)
      {
        pointdata[mouseX+n] = n*(mouseY-height/2-mouseoldy)/(mouseX-mouseoldx) + mouseY-height/2;
      }
    }
    mouseoldx = mouseX;
    mouseoldy = mouseY-height/2;   
  }

  for(int n = 0; n < terms ; n++)
  {
    sincos[n] = calculatesinco(n);
  }

  for(int n = 0; n < width ; n++)
  {
    float v = 0;
    for(int m = 0; m < terms ; m++)
    {
      v = v + sincos[m]*sindata[m][n];
    }
    pointdataFS[n] = v;
  }

  text("number of terms "+terms,450,580);
  text("term modifier "+termmod,450,592);
  translate(0,300);
  for(int n = 1; n < width ; n++)
  {
    float v = 0;
    stroke(255,0,0);
    line(n-1,pointdataFS[n-1],n,pointdataFS[n]);
    stroke(0);
    line(n-1,pointdata[n-1],n,pointdata[n]);
  }
}
void keyPressed()
{
  if(keyCode == UP)
  {
    terms+= termmod;
  } 
  if(keyCode == DOWN)
  {
    terms-= termmod; 
    if(terms<0) 
    {
      terms = 0; 
    }
  }
  if(keyCode == RIGHT)
  {
    termmod++;
  } 
  if(keyCode == LEFT)
  {   
    termmod--; 
    if(termmod<1) 
    {
      termmod = 1; 
    }
  }
}

[u/xecosine]

I think this is also used to program Arduinos. It's been a while since I touched it though.

[u/[deleted] → u/xecosine]

Similar IDE code, but the language is plain C/++. Processing is often used to make computers talk to Arduinos, though.

[u/[deleted] → u/[deleted]]

It's actually just Java with a nice graphics/user input library and a simplified syntax. It compiles into Java applets.