fixing bug #1539 in LinearMapper where map_screen() was always assuming data_array is an array
fixing bug #1539 in LinearMapper where map_screen() was always assuming data_array is an array

ContinuumIO/chaco,ContinuumIO/chaco,burnpanck/chaco,ContinuumIO/chaco,burnpanck/chaco,burnpanck/chaco,tommy-u/chaco,tommy-u/chaco,tommy-u/chaco,ContinuumIO/chaco