Two example are attached for interaction diagrams of RC columns with rectangular and circular tubes using the function Interaction_Diagrams.

function Interaction_Diagrams(x,y,x_s,y_s,a_s,fc,fy,E)

Input:

x: x coordiantes of section vertix vector (mm)
y: y coordinates of section vertix vector (mm)
a_s: area of steel bars vector (mm^2)
x_s: x coordinates of steel bars vector (mm)
y_s: y coordinates of steel bars vector (mm)
fc: compressive strength of concrete (MPa)
fy: yield stress of steel vector (MPa)
E: modulus of elasticity of steel vector (MPa)

Output:

Column section, failure envelope, interaction diagrams in x and y directions are plotted in one figure.