added r fn to generate a cool 1d series with an abrupt transsition, useful for testing multifit
added r fn to generate a cool 1d series with an abrupt transsition, useful for testing multifit

jackdawjackdaw/emulator,jackdawjackdaw/emulator,MADAI/MADAIEmulator,jackdawjackdaw/emulator,jackdawjackdaw/emulator,MADAI/MADAIEmulator,MADAI/MADAIEmulator,MADAI/MADAIEmulator