Thread: Three dimensional array in Java Help

I am working with datasets that contain x,y,z coordinates for each position (size = 40,40,40 for this instance).
My understanding is that java treats arrays differently to other languages like c etc, so if i need to access x data i need to use:

// i have already read in the values from the dataset file to an int[40][40][40] array called data.  
for (i=0;i<int.length;i++){  
    for (j=0;i<int[i].length;j++){  
        out.println("x data = "+ data[0][i][j];  
}  
}

And to access y variables held in this dataset

for (i=0;i<int.length;i++){  
    for (j=0;i<int[i].length;j++){  
        out.println("x data = "+ data[1][i][j];  
}  
}

Similarly for z it must be data[2][i][j]

Is my understanding correct?

Or is it more like [x][y][z] access? i.e.

for (int i = 0; i < data.length; i++) {  
                for (int j = 0; j < data.length; j++) {  
                    for (int k = 0; k < data.length; k++) {  
                        out.println("{" + i + ", " + j + ", " + k + "}=\t" + data[i][j][k]);  
                        count++;  
                    }  
                }  
            }

There is a dearth of material available when i searched for multi-dimensional arrays so pardon me if this is too beginner a question. Thanks for looking,>

http://www.youtube.com/watch?v=ctab5xPv-Vk

Originally Posted by Chris.Brown.SPE

Interesting take Norm. I guess we need the question answered...

Are you looking for "an array to hold x,y,z positions" or "a 3D array holding data at position x,y,z"?

Hi Chris, I need to hold data about a 3D image. So needs to hold x,y,z positions about each pixel.

The data is loaded into an int[][][] array by an external .jar library whose source i do not have so i cannot do any other way but this.

To correct you each position only holds one scalar value. i.e.
data[1][1][0] = 5

This is where it gets confusing. The 5 above is the colour of the position which is used to colour that pixel.

Originally Posted by Norm

Once the data is loaded into the array, what does the program use it for?

I am using it to draw an represent a 3-D image. so i will plot each pixel manually using the data in the array.

Another use of the the scalar data contained in each position will be to use it to set the colour of the pixel.

--- Update ---

Originally Posted by Chris.Brown.SPE

So the array itself is a representation of the image. One array dimension for each dimension of the image and the value is the color of the pixes.

This will work as i stated in my original post. data[x-axis][y-axis][z-axis]

The problem is extracting individual values for x and y (since you need both to plot the image). I am only plotting in two dimensions.
So if i wanted to plot all pixels in z=1 dimension, how do i extract all x and y values?
i.e. all combinations of data[x][y][5] where x and y are indices.

Originally Posted by Norm

If you set one of the dimensions (z) to a constant value (5), there would be 40X40 values in the other two dimemsions

Hi,

That bit i understand. What i dont understand is getting seperate x and y values since i need them in JOGL to plot this pixel.
For instance

data[1][0][5]
data[1][1][5]
data[1][2][5]

will give me data held at index 1,0; 1,1; 1,2 (for fixed z-dim 5)
Note these are indices not x,y coordinates.

At each of these locations, a double value is held which determines the colour of the pixel.

This is slightly confusing as indices and coordinates are seperate in this question.

After much tweaking and deliberation, i managed to fix it. Both of you were right! The indices were indeed coordinates. The value held at each index location represented the colour of the pixel.
First setting the color, then plotting the pixel using an iteration for all possible indexes, i was able to model the image. Thanks once again for your help.
I just made a mountain out of a molehill.