Connecting Data Points

General Discussion Other

wired632

in General Discussion • Other • 1 year ago

I am writing a program that graphs a set of data points from a spreadsheet. Now I need to connect the points using a continuous line. How do I go about coding this properly?

Replies(4)

andrewgie..

Re: Connecting Data Points

1 year ago

first, I know of no way to import a spreadsheet into processing, so you probably want to make a text file. Use an array and a for loop to connect the points in one step.

wired632

Re: Connecting Data Points

1 year ago

I already have the data from the spreadsheet stored in the program what I need to know is how to make a line that connects each of the data points.

PhiLho

You need to sort your data by growing x, if not already done. Then you can use a for loop to iterate on the set of points, and use line() to connect them.
Showing some code helps in discussing on concrete things instead of speculating on what you have...

wired632

Re: Connecting Data Points

1 year ago

The code so far:

class Plot {

float lowX,hiX,lowY,hiY;

float startLowX,startHiX,startLowY,startHiY;

int border;

float xTickInterval, yTickInterval;

String xLabel,yLabel,title;

float[] xdata;

float[] ydata;

Plot(float templowX, float temphiX, float templowY, float temphiY, String xLabel, String yLabel, String title) {

this(templowX,temphiX,templowY,temphiY);

this.xLabel=xLabel;

this.yLabel=yLabel;

this.title=title;

}

Plot(float templowX, float temphiX, float templowY, float temphiY) {

lowX=templowX;

hiX=temphiX;

lowY=templowY;

hiY=temphiY;

border=50;

xTickInterval=(hiX-lowX)/10;

yTickInterval=(hiY-lowY)/10;

startLowX=lowX;

startHiX=hiX;

startLowY=lowY;

startHiY=hiY;

xLabel="X";

yLabel="Y";

title="";

}

//accessor methods to find out what the range of x and y values are

float getXLow() {

return lowX;

}

float getXHi() {

return hiX;

}

float getYLow() {

return lowY;

}

float getYHi() {

return hiY;

}

void addData(float[] x, float[] y){

xdata=x;

ydata=y;

}

void drawFunc() {

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

float x=remapX(xdata[i]);

float y=remapY(ydata[i]);

ellipse(x,y,5,5);

}

//draws the axes, the function, the lines connecting mouse to axes, and the labels on the screen

void draw() {

//drawFunc();

//draw axes

drawAxes();

//draw function

drawFunc();

//clear off edges

fill(255);

noStroke();

rect(0,0,width,border);

rect(0,0,border,height);

rect(0,height-border+1,width,border);

rect(width-border+1,0,border,height);

//draw border labels

fill(0);

stroke(0);

textSize(18);

//textAlign(CENTER);

text(xLabel,width/2-textWidth(xLabel)/2,height-border/2);

//draw border values

//textAlign(LEFT);

text(lowX,border,height-border/2);

textAlign(RIGHT);

text(hiX,width-border,height-border/2);

//textAlign(CENTER);

pushMatrix();

translate(border/2,height/2);

rotate(radians(-90));

textAlign(LEFT);

text(yLabel,-textWidth(yLabel)/2,0);

popMatrix();

pushMatrix();

translate(border/2,border);

rotate(radians(-90));

textAlign(RIGHT);

text(hiY,0,0);

popMatrix();

pushMatrix();

translate(border/2,height-border);

rotate(radians(-90));

textAlign(LEFT);

text(lowY,0,0);

popMatrix();

int titleSize=32;

textSize(titleSize);

//textAlign(CENTER);

text(title,width/2-textWidth(title)/2,border/2+titleSize/2);

}

//draws the axes on the screen

void drawAxes() {

textSize(10);

//background color of graph

fill(220);

stroke(220);

rect(0,0,width,height);

stroke(0);

noFill();

float axisSize=1.0;

strokeWeight(axisSize);

//outline

rect(border,border,width-2*border,height-2*border);

strokeWeight(2);

//x axis

float screenX1=remapX(lowX);

float screenX2=remapX(hiX);

float screenY=remapY(0);

if (screenY>=border && screenY<=height-border-2*axisSize) {

line(screenX1,screenY,screenX2,screenY);

}

//add ticks for x axis

fill(0);

textAlign(CENTER);

for(float x=0;x<=hiX;x+=xTickInterval) {

float tickX=remapX(x);

float tickY=(screenY>=border&&screenY<=(height-border))?remapY(0):height-border-2*axisSize;

line(tickX,tickY-2*axisSize,tickX,tickY+2*axisSize);

if (x!=0) {

fill(0,0,0);

text(x,tickX,tickY-2*axisSize-2);

}

for(float x=0;x>=lowX;x-=xTickInterval) {

float tickX=remapX(x);

float tickY=(screenY>=border&&screenY<=(height-border))?remapY(0):height-border-2*axisSize;

line(tickX,tickY-2*axisSize,tickX,tickY+2*axisSize);

if (x!=0) text(x,tickX,tickY-2*axisSize-2);

}

//y axis

float screenX=remapX(0);

float screenY1=remapY(lowY);

float screenY2=remapY(hiY);

if (screenX>=border && screenX<=width-border) {

line(screenX,screenY1,screenX,screenY2);

}

//add ticks for y axis

textAlign(LEFT);

for(float y=0;y<=hiY;y+=yTickInterval) {

float tickY=remapY(y);

float tickX=(screenX>=border&&screenX<=(width-border))?remapX(0):border+2*axisSize;

line(tickX-2*axisSize,tickY,tickX+2*axisSize,tickY);

if (y!=0) text(y,tickX+2*axisSize,tickY);

}

for(float y=0;y>=lowY;y-=yTickInterval) {

float tickY=remapY(y);

float tickX=(screenX>=border&&screenX<=(width-border))?remapX(0):border+2*axisSize;

line(tickX-2*axisSize,tickY,tickX+2*axisSize,tickY);

if (y!=0) text(y,tickX+2*axisSize,tickY);

}

//change from our coordinate system to screen coordinate system

float remapX(float x) {

return map(x,lowX,hiX,border,width-border);

}

float remapY(float y) {

return map(y,lowY,hiY,height-border,border);

}

//change from screen coordinate system to our coordinate system

float unMapX(float x) {

return map(x,border,width-border,lowX,hiX);

}

float unMapY(float y) {

return map(y,height-border,border,lowY,hiY);

}

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