Processing 1.0 - Processing Discourse - data table for color values

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data table for color values (Read 947 times)

leanderlike

data table for color values
Nov 7^th, 2008, 11:07am

I have a data table with two columns. in the first column in have values from 0 to 999. in the second column are color values like #111111.
so consequently it looks like this.

0 #FF0000
1 #FFFF00
2 #FF00FF
3 #FFFFFF

now, i want to use this color values to fill an ellipse. depending on the number in the first column the color value in the second column has to be used.

in several examples i only found a way, to use all values of the data table at the same time. but i actually only need one value out of those 1000. what sort of function or piece of code do i have to use to compare the value in my application with the value in my data table?

I'm glad for help and many thanks in advance!!

fry

Re: data table for color values
Reply #1 - Nov 7^th, 2008, 7:56pm

Code:


String[] lines = loadStrings("colors.txt");
int[] colorList = new int[lines.length];
for (int i = 0; i < lines.length; i++) {
  // I assume that it's tabs separating the columns
  int tab = lines[i].indexOf(TAB);
  // Skip over the TAB character, and the # character
  String stuff = lines[i].substring(tab + 2); 
  // Convert the color from hex
  int c = unhex(stuff);
  // Put it in the list, the 0xff part makes it opaque
  colorList[i] = 0xFF000000 | c;
}

Then you can use fill(colorList[4]) or whatever.. Or if you're comparing against another color (I didn't quite follow your question), you can go through colorList to see what matches.

leanderlike

Re: data table for color values
Reply #2 - Nov 8^th, 2008, 2:50pm

thanks a lot, thats what i was looking for.

there's just one more problem using this script.

when using my application you are supposed to type in a number. let' s say 29. And after pressing ENTER a rect appears in the middle of the screen and this rect is supposed to be filled with a certain color out of the data table. so when typing 29, the programm has to pick up the color that is in one row with 29.

How can I compare the value of an int to a value inside my data table?

using colorList [29] might be a possibilitly, but the numbers are not from 0 to 999, as there are skips like

520
522
540

so the 540. position in the data table must not be equal to the number 540.
If there is a possibility to get to the number one has typed in it would be great!!!

PhiLho

Re: data table for color values
Reply #3 - Nov 8^th, 2008, 4:04pm

There are two possibilities:
- the simpler is to just read as fry shown, but also taking the index from the file, and using this index to put the color in the table at the right place:

read line
separate it at tab place, into index and color
colorList[index] = color

You will have holes, but that's not important, an array of 1000 entries isn't a big deal today. You will have to manage when user types a number corresponding to an empty row.

- Another solution would be to use a HashMap, a good way to handle sparse arrays.

leanderlike

Re: data table for color values
Reply #4 - Nov 9^th, 2008, 6:10pm

ahh, i don't know what i made wrong, but when executing the script you've written i get this error:
java.lang.NumberFormatException: For input string: "FF0000 "

this is my script

String[] lines = loadStrings("colors.txt");
int[] colorList = new int[lines.length];
for (int i = 0; i < lines.length; i++) {
// I assume that it's tabs separating the columns
int tab = lines[i].indexOf(TAB);
// Skip over the TAB character, and the # character
String stuff = lines[i].substring(tab +1);
// Convert the color from hex
int c = unhex(stuff);
// Put it in the list, the 0xff part makes it opaque
colorList[i] = 0xFF000000 | c;
}

and this is my colors.txt file:

01#FF0000
02#FFFF00
03#FF00FF
04#FFFFFF
05
06#00FFFF

between the number 01, 02 etc. and the hex codes is a Tab.

koogy

Re: data table for color values
Reply #5 - Nov 9^th, 2008, 8:07pm

the unhex manual page uses an 8 hex digit input, maybe that's the problem (haven't tested it)

your colors.txt file also looks to be missing the tab separator that the code's expecting (although that may be a pasting problem). println("Stuff: [" + stuff + "]"); before the unhex() to make sure.

> between the number 01, 02 etc. and the hex codes is a Tab.

ah, ok 8)

> For input string: "FF0000 "

trailing space?

leanderlike

Re: data table for color values
Reply #6 - Nov 9^th, 2008, 11:14pm

the colors.txt is indeed just a pasting problem. in my real file there is tab between each 01, 02 etc. and the hex code.

i tried: println("Stuff: [" + stuff + "]");

and it gave me:

Stuff: [ #FF0000 ]
Stuff: [ #FFFF00 ]
Stuff: [ #FF00FF ]
Stuff: [ #FFFFFF]

but when using the unhex it still gives me the error:
java.lang.NumberFormatException: For input string: "FF0000 "

i don't know what might be wrong...

PhiLho

Re: data table for color values
Reply #7 - Nov 10^th, 2008, 7:34am

Code:

String[] lines = {
"01#FF0000",
"02#FFFF00",
"03#FF00FF",
"04#FFFFFF",
"06#00FFFF",
};  
int[] colorList = new int[1000]; 
for (int i = 0; i < lines.length; i++) {  
  // I assume that it's tabs separating the columns  
  int tab = lines[i].indexOf(TAB);  
  // Get index value
  String idx = lines[i].substring(0, tab);
  int index = int(idx);
  // Skip over the TAB character, and the # character  
  String stuff = lines[i].substring(tab + 2);  
//  println(index + "-" + stuff + ".");
  // Convert the color from hex  
  int c = unhex(stuff.trim());  
  // Put it in the list, the 0xff part makes it opaque  
  colorList[index] = 0xFF000000 | c;  
}
exit();

Several problems: we needed tab+2, not tab+1. We needed to trim the input (or remove the extra spaces in the file). You should not leave numbers without color values, or you should handle this case (no "stuff" value). So I made as suggested, a big array and put color at the read index.

leanderlike Junior Member Offline Posts: 91	Re: data table for color values Reply #8 - Nov 10^th, 2008, 3:49pm don't know what's going wrong with me...when executing the script it highlightes the Sting idx = lines [i].substring (0,tab); and as an error i get: java.lang.StringIndexOutOfBoundsException: String index out of range: -1

PhiLho YaBB Moderator Offline Posts: 4190 Near Paris (France)	Re: data table for color values Reply #9 - Nov 10^th, 2008, 7:46pm As I wrote, you must either get rid of lines without color values (and probably no tabs, hence the -1 value in tab variable), or handle this case (testing the value, as we should have done anyway...).

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