Why did Jonah try to run away from God?

According to Jonah 4:1-2, after God had mercy on Nineveh, "it displeased Jonah." He wanted judgement and condemnation on the people of Nineveh. He knew God will have mercy and compassion on his creations so he decided to flee instead of passing God's message. "Therefore I fled before unto Tarshish: for I knew that thou art a gracious God, and merciful, slow to anger, and of great kindness, and repentest thee of the evil."