The non-linear V/I characteristic of the diodes is being used to progressively compress the peaks of the triangle wave so it approximates to a sine wave.The diodes block the input to the opamp. Remove them or explain why they are there.
The two 15V batteries, the two 50k resistors and the 200 ohm resistor also do not do anything and should be removed or explain why they are there.
It should be like this:
what do you mean by how good is my sine wave?shape?harmonic?How good is the sine-wave?
If you add more diodes and resistors then the triangle wave will have more breakpoints.ya,i also thought like that too,abit sharp on top and bottom.so you know how to improve it?
Or read the full document I supplied to you in the other thread. It includes a rudimentary program to go stepwise through the approximations of the section slopes... Post #3 here http://forum.allaboutcircuits.com/showthread.php?t=32396You must plan and calculate the resistor values and input amplitude for low distortion.
Yours appear to be random.
Ask your teacher to explain how to do it.