Means you are missing ImageMagic. If you're getting this error on ieng6, please notify a TA. On Linux run 'sudo apt-get install imagemagick'. On other machines, see http://www.imagemagick.org/ for details on installing.
Yes, all of the inputs are in the range [-1.0, 1.0]. This is specified in the assignment!
Run the eog filename command. If you are ssh-ing into ieng6, makesure you passed the -X option to ssh.
ppm/pgm images are intermediary images generated by our code while evaluating your provided functions for each pixel. The fact that you only see the ppm/pgm files and no jpg files, indicates that your code failed while generating the image. Look through the output for any exceptions.
The specified depth is an UPPER bound. Your build function should also generate expressions that have branches of depth less then the passed in maximum.
Two things to check: 1) Are you passing in too large depths to build? You probably shouldn't go more than 20. 2) Does your build function alwas generate expressions of the maximum depth (see above q)?
Use sin/cos etc instead of Math.sin, Math.cos
Check whether the bounds on rand in build2 are such, so that it may return numbers causing your NEW custom operators to be returned
No. seed1 and seed2 are passed to rand by our own code. You need to explicitly call rand inside build, build2 with the range in which you want the random number to be.
Your code is given 5 minutes to generate each of the 6 pictures you are submitting. If it takes more than that we assume it timed out.
Yes. Specified in the assignment.
Check the values passed to rand when selecting between varX and varY. Remember that (rand x y) generates a value in the range [x,y).