Non linear path transition

-- local easing functions
local pow = math.pow
local sin = math.sin
local pi = math.pi
local rand = math.random
local abs = math.abs


function easeTrow(t, tMax, start, delta, high)
    local x = (t / tMax) - 0.5
    return start + high * 4 * x * x - high + delta * (t / tMax)
end




local square = display.newRect( 0, 0, 50, 50 )
square:setFillColor( 255,255,255 )

local _W, _H = display.contentWidth, display.contentHeight
local _CX, _CY = _W * 0.5, _H * 0.5

square.x = 0
square.y = _H * 0.8

local howHighToTrow = _H * 0.5
local trowDuration = 700

transition.to( square, { time = trowDuration, x = _W} )
-- try also
-- transition.to( square, { time = trowDuration, x = _W, transition = easing.inQuad} )
transition.to( square, { time = trowDuration, y = _CY, transition = function (a, b, c, d) return easeTrow (a, b, c, d, howHighToTrow) end } )