Help a noob with syntax!

Okay I'm really new to Matlab and trying to code something for my assignment. Can someone please look at this code and tell me what all is wrong? I'm damn sure there is some syntax problem! The error I'm getting right now is:

Subscript indices must either be real
positive integers or logicals.

Error in RectangularSection (line 5)
  D(i) = DeltaY*x;

CODE:

function [N]=RectangularSection(BaseWidth,Depth,RoughnessBase,RoughnessLeftFace,RoughnessRightFace,NoOfSections)

if NoOfSections > 0

DeltaY = Depth/NoOfSections;

for x=0:NoOfSections

    D(i) = DeltaY*x;

N(i) = ((BaseWidth*RoughnessBase^(3/2)+DeltaY*x*RoughnessLeftFace^(3/2)+DeltaY*x*RoughnessRightFace^(3/2))/(BaseWidth + 2*x*DeltaY))^(2/3);

end

plot(N,D)

title('Roughness vs Depth');

xlabel('Depth');

ylabel('Roughness');

end

Answer 1

[Walter Roberson]

That is not a syntax error. You have not assigned a value to "i", so it has it's default value, and the default value for "i" (and for "j" as well) is sqrt(-1)