I have a formula to compute the deflection of a beam.
When I have computed the deflection I get a vector with non-negative elements representing the deflection in each position on the beam.
When I am plotting the deflection vector I get a downwards parabola since the elements are positive.
But now I found this plot somewhere else
I guess the plot illustrates how the beam is bending at positions where loads are placed.
Is it correct to get negative deflections? I wonder if I need to multiply my elements in my deflection vector by -1 in order to obtain the same plot as shown here.