function sview(a)
if a=='r'
    view(-35,-30)
end
if a=='f'
    view(-0,0)
end
if a=='f'
    view(-0,0)
    %viewing direction perp to y 
end
if a=='s'
    view(-90,0)
    %viewing direction perp to x
end
if a=='t'
    view(0,-90)
    %viewing  perp to direction in z
end