Errata

In the last paragraph, change "processing-1.0" to "processing-2.0"

Change URL in the first paragraph to:
http://wiki.processing.org/w/Troubleshooting

The variable diameter is defined but never used in the example.

Note from the Author or Editor:
Yes, good catch. The third line of Example 5-8 on page 56 should be removed.

On line 17 of the code listing for Example 7-6, the text reads:

x = startX + ((stopX - startX) * pct);

And it should read:

y = startY + ((stopY - startY) * pct);

Note from the Author or Editor:
Yes, good catch. It's line 19 if you count the spaces. The line that reads "y = startY + ((stopY-startX) * pct);" should be "y = startY + ((stopY-startY) * pct);"

The array declarations in this listing do not match the rest of the examples in the book. The lines that read:

int x[] = new int[num];
int y[] = new int[num];

Should read:

int[] x = new int[num];
int[] y = new int[num];

Although this is not a syntax error, the style of the existing array declarations in code listing 10-9 is discouraged in Java.

Note from the Author or Editor:
Yes, another good find. So, for example 10-09, the first three lines should read:

int num = 60;
int[] x = new int[num];
int[] y = new int[num];

In Example 10-11, the code implies that the files in the media.zip download are numbered from 0001 to 0012, but in fact the download has them as 0000-0011. In the intro paragraph it starts with "frame-0001.png" instead of 0000, and the two assignments of currentFrame are to 1 instead of 0.

It still works with 1 (as it does if they're both 11), but it's confusing this way. Also, the

if (currentFrame >= images.length)

is also confusing. If it's incrementing, how would it be greater than 12? why not use

if (currentFram == images.length)

instead?

Great book -- very well done. Thanks!

Note from the Author or Editor:
Yes, this is improved by updating the text and the code. The text should read "The images are named sequentially (frame-0000.png,
frame-0001.png, and so forth),"... And the code should be:

int numFrames = 12; // The number of frames
PImage[] images = new PImage[numFrames]; // Make the array
int currentFrame = 0;

void setup() {
size(240, 120);
for (int i = 0; i < images.length; i++) {
String imageName = "frame-" + nf(i, 4) + ".png";
images[i] = loadImage(imageName); // Load each image
}
frameRate(24);
}

void draw() {
image(images[currentFrame], 0, 0);
currentFrame++; // Next frame
if (currentFrame == images.length) {
currentFrame = 0; // Return to first frame
}
}

From the Processing Issues Database (Issue 414)

original code:
void draw() {
if (port.available() > 0) {
val = port.read();
val = map(val, 0, 255, 0, height);
}

error:
change "height" to "height/2"

I have tested the code. It seems "height/2" works well. However, please let me know if I am wrong. Thanks.