Bill David,
I can see several possibilities for an empty array:
1. You initialize the shift register with an empty array, so if nothing ever gets added to the array it will remain empty.
2. Part of the image is cut off. If an empty string is passed (although you may be testing for this in the cut off portion), the array will be empty.
3. If a non-empty strnig is passed but its format or contents does not translate to a non-empty array of strings, the output of the for loop will be an empty array.
Some additional possiblities could produce non-empty arrays with all zeros, NaN, or Infinities, but those would generate different errors.
Try putting indicators on the data string, on the string array, and on the numeric array to see what you are getting.
Lynn
