2D Array with Shift

vangalvin

I have several sensors on my arduino that I would like to log

Data comes from the Arduino in the form of a string and is formatted in the following manner (there are 6 fields)

"10.2", "123.33", "0.00", "1023.00", "99.01", "256.9"/r

in processing I am reading the string then splitting and converting it in to a float and that seems to be working fine.

What I need to do is store the information in an array so I can output the information however I also need to be able to shift the last readings in and out as I would like to keep track of the last 60 values for each sensor.

for example

{0}, {0, 1, 2, 3, -> whatever the incoming values are etc-> 58, 59, 60};

When a new value comes in the new values is added and shifted to the left.

{0}, {1, 2, 3, 4, -> whatever the incoming values are etc-> 59, 60, 61};

Ideally i would like to do this without using loops as some of the other functions are kind of time critical.

I hope that made sense and thanks in advance for any assistance or ideas on this.

TfGuy44

class DataSet {
  float[] data = new float[6];
  DataSet(float a, float b, float a, float b, float a, float b ){
     data[0] = a;
     data[1] = b;
     data[2] = c;
     data[3] = d;
     data[4] = e;
     data[5] = f;
  }
}

ArrayList<DataSet> lastSixty = new ArrayList();

// Add new data to end:
lastSixty.add( new DataSet( 1, 2, 3, 4, 5, 6 ) );

// Remove oldest data:
lastSixty.remove(0);

// Maintain sixty data:
while( lastSixty.size() > 60 ){ lastSixty.remove(0); }

// Access the 5th most recent record's third data:
println( lastSixty.get(lastSixty.size() - 5 ).data[2] );

vangalvin

Thanks @TfGuy44 will try that out. looks a lot less complex than the way I was trying to do it.

vangalvin

Not sure if i'm holding my tongue on the right angle for this one..

Seems that no matter what I add in to lastSixty the length is allays 1.

`class DataSet { float[] data = new float[6]; DataSet(float a, float b, float c, float d, float e, float f ){ data[0] = a; data[1] = b; data[2] = c; data[3] = d; data[4] = e; data[5] = f; } } ArrayList lastSixty;

void setup() { size(640, 360); lastSixty = new ArrayList();

// Add new data to end: lastSixty.add(new DataSet(1, 2, 3, 4, 5, 6)); }

void draw() {

//ArrayList lastSixty = new ArrayList(); // Remove oldest data: //lastSixty.remove(0);

// Maintain sixty data: //while( lastSixty.size() > 60 ){ lastSixty.remove(0); }

println(lastSixty.size()); // println(lastSixty.get(2));

// Access the 5th most recent record's third data: //println( lastSixty.get(lastSixty.size() - 5 ).data[2] ); }`

vangalvin

Doh... Scratch that... I just realised I was looking at the array the wrong way around... Typical..!! guess that's what you get from being on the bottom side of the planet :)

Chrisir

Australia?

vangalvin

@Chrisir Close, but a little Further down :P New Zealand :)

Chrisir

;-)

Chrisir

You make your life easier when you tell the ArrayList its class.

Greetings to New Zealand

Chrisir ;-)

class DataSet { 

  float[] data = new float[6];

  //constructor 
  DataSet(float a, float b, float c, float d, float e, float f ) { 
    data[0] = a; 
    data[1] = b; 
    data[2] = c; 
    data[3] = d; 
    data[4] = e; 
    data[5] = f;
  }//constructor 

  String toString() {
    String result="";

    for (float f1 : data ) 
      result+=str(f1)+"; ";

    // clean ending: 
    if (result.length()>2) {
      result=result.substring(0, result.length()-2); 
      result+=".";
    }
    return result;
  }//method 
  //
}//class 

//=======================================================

ArrayList<DataSet> lastSixty;

void setup() { 
  size(640, 360); 

  fill(0);
  text("See direct window", 19, 19);

  //ArrayList 
  lastSixty = new ArrayList();

  // Add new data to end:
  lastSixty.add(new DataSet(1, 2, 3, 4, 5, 6));
  lastSixty.add(new DataSet(21, 22, 23, 24, 25, 26));
  lastSixty.add(new DataSet(41, 42, 43, 44, 45, 46));
  lastSixty.add(new DataSet(61, 62, 63, 64, 65, 66));
  lastSixty.add(new DataSet(71, 72, 73, 74, 75, 76));
}

void draw() {

  // Remove oldest data: 
  // lastSixty.remove(0);

  // Maintain sixty data: //
  while ( lastSixty.size() > 60 ) { 
    lastSixty.remove(0);
  }

  println("size: "+lastSixty.size());
  println("--------------------------------------");
  println("2nd data set");
  printArray(lastSixty.get(2).data);
  println("Same as: " +lastSixty.get(2).toString()); 
  println("--------------------------------------");

  // Access the 2nd most recent record's third data: //
  DataSet d1 = lastSixty.get( lastSixty.size() - 2 ) ;  
  println("Last but 2 data set, item 2: " + d1.data[2] );

  noLoop();
}
//

Chrisir

this is with noLoop()... you want to comment that out later

vangalvin

Thanks @Chrisir, Yes using a dataset really did make it so much easier :) where are you from?

Chrisir

using a dataset really did make it so much easier

That's this line:

ArrayList<DataSet> lastSixty;

(just to make sure we are on the same page ;-) )

I am from Germany

vangalvin

:) We are in the same memory space. Thanks

vangalvin

@Chrisir is there a way to get the size of data[] to see how many sensors are in there? kind of like a println(data.size())?

kfrajer

data.length

More in the reference: https://processing.org/reference/Array.html

Kf