I recently bought an HP-50G. Overall I like it, even though the CAS implementation is at times cumbersome (why COLLECT, EXPAND, LIN are not easily available from the equation writer? And why LIN is not the default?).
I find the "Fast 3D" plots quite unusable, on the other hand. The z axis points arbitrarily, and even when I manage to make it point up, any rotation of the other axes is likely to move the z-axis off vertical. Understanding where the axes point in the first place is a challenge. Overall, I am completely disoriented, and about all I can tell of a surface is whether it is flat or not. Octave + gnuplot are infinitely better!
Is there a better implementation of Fast 3D plots available?
I tried HLDRAW, but it does not seem to work with the 50g and the new (lastest released by HP) firmware.
Thanks!
Luca