I do not understand what you mean with a noisy array? An array filled with uniform values has no noise at all. 
If you need a 1-D-Array fill one with the random function with fitting values. Here some code with more or less "noisy" elements shown in a graphic.

1. float[][] pixel;
   float r;
   //set noise to a value between o and 100
   int noise = 100;
   
   size(200, 200);
   background(255);
   pixel = new float[width][height];
   for(int i=0; i<height; i++) {
     for(int j=0; j<width; j++) {
       pixel[j][i] = random(100/noise)*255;
     }
   }
   
   for(int i=0; i<height; i+=1) {
     for(int j=0; j<width; j+=1) {
       stroke(pixel[j][i]);
       point(j, i);
     }
   }
   

The best way is probably to use the noise() function, but perhaps I didn't understand your question...