How to set Vref of Opamp in adhLib

Hi everyone,

I use Opamp in adhLib to simulate the inverting voltage circuit.

with input Voltage is linear funtion in range -1 to 1 ( I use Vpwlf to make it)

My point is with input Voltage in [-1;0], the ouput of opamp is zero. And with voltage in [0;1], the ouput is inverted to [0; -1].

So I use Single Supply Voltage.

This is my circuit and results.

Can you tell me why I cannot get my point?

Thank you