I am having an Issue

Processing Coding Questions
1

I am trying to make a bar graph for the following data however my “i” integer is not being recognized.

String[] name = {
“1997:”,
“1998:”,
“1999:”,
“2000:”,
“2001:”,
“2002:”,
“2003:”,
“2004:”,
“2005:”,
“2006:”,
“2007:”,
“2008:”,
“2009:”,
“2010:”,
“2011:”,
“2012:”,
“2013:”,
“2014:”,
“2015:”,
“2016:”,
};

int[] fires = {

6,835 ,
5,227 ,
7,562 ,
5,177 ,
6,223 ,
5,759 ,
5,961 ,
5,574 ,
4,908 ,
4,805 ,
3,610 ,
3,593 ,
2,858 ,
2,434 ,
3,056 ,
2,922 ,
3,672 ,
2,920 ,
3,231 ,
2,816 ,
};

void setup(){
size(500,500);
}

void draw(){
int x =0;
for(int i=0; i<10; i++){

if(mouseX>x && mouseX<=x+40){
  fill(255, 96, 79);
}else{
  fill(255, 36, 13);
}

}

float h = map(fires[i], 2300, 7600, 36, 340);

rect(x+4, height-h, 32, h);

x+=8;
}

I am very new to processing and need some help.

2

The brace that ends the for loop seems to be in the wrong place. It should probably be after the x += 8 line?

3

I changed that however when I run it now I get an error “ArrayIndexOutOfBoundsException: 40” with my float h line being highlighted

4

Hi magic_moose,

You can use name.length and fires.length to find the number of entries you have in each of your arrays. This will help when using a for-loop to run through them. By my count, name has 20 entries while fires has 40. I’m assuming that there’s a connection between the two, like every 2 entries in fires is to be matched with every 1 entry in name?

void setup() {
  size(500, 500);
  println("name's length", name.length);
  println("fires's length", fires.length);

  int minsz = min(fires.length, name.length);
  int relsz = max(fires.length, name.length) / minsz;
  println(relsz);

  for (int i = 0, j = 0; i < minsz; ++i, j += relsz) {
    println(name[i], fires[j], ",", fires[j + 1]);
  }
}

You can work with more than one variable in your for-loop to keep your arrays in sync. In this case, my variable i is matched with the name array, while j is matched with the fires array. Because fires is twice as big, j must be incremented twice as fast as i. This is why I used j += relsz (relative size or length, 2) in the third section of the for-loop. i and j only exist within the for-loop, and disappear from memory after it finishes. minsz and relsz will disappear after setup finishes.

A sample of what this sketch will print in the console:

1997: 6 , 835
1998: 5 , 227
1999: 7 , 562
2000: 5 , 177

I recommend watching Dan Shiffman’s videos, particularly this one on variable scope. Depending on where a variable like float h is located relative to your curly braces, { and }, Processing may not know that it exists or what information it contains.

Hope that helps out!

5

Thank you for the help however where it comes with 40 outputs it was meant to be 20. the commas in the numbers were just to show a number placement ex: 1,000 = 1000.

Sorry for the confusion, I am just very very lost

6

Hi magic_moose,

It’s very helpful that you pointed that out. Those commas are confusing Processing, too, because it uses commas to separate entries in an array, not for grouping within a number. So, although this isn’t solving your big problem yet, you can now get rid of a small problem which is making the bigger one harder to solve.

int[] fires = {
  6835, 5227, 7562, 5177, 6223,
  5759, 5961, 5574, 4908, 4805, 
  3610, 3593, 2858, 2434, 3056, 
  2922, 3672, 2920, 3231, 2816
};

int sz = fires.length;
for(int i = 0; i < sz; ++i) {
  println(i + 1, nfc(fires[i]));
}

If in the future I ever want to display the values in fires with commas to make them easier to read I can use nfc. (How I treat my information when I’m working in code is a separate design issue from how I format and display it to other people.)

Figuring out how to draw rectangles on the screen with a for-loop might be another sub-problem which will get you closer to your big goal. Again, Shiffman’s videos are helpful, in my opinion.

Best,