MATLAB Answers

Error using sym/subsindex

2 views (last 30 days)
Susmit Kumar Sahu
Susmit Kumar Sahu on 9 Jul 2020
Answered: Devineni Aslesha on 22 Jul 2020
I need to make this code work.
Trying for 2 days, Please someone help me to debug this error.
Error displayed
Start = input("Enter the Start value: ");
End = input("Enter the End value: ");
grid_size = input("Enter the grid size: ");
np = input("Enter the number of input points: ");
x = zeros(1,np,'uint32');
y = zeros(1,np,'uint32');
i = 1;
while i <= np
x(i) = input("Coordinates of X value: ");
y(i) = input("Coordinates of y value: ");
i = i + 1;
j = 1;
px = zeros(1,np);
py = zeros(1,np);
syms j
for t =0:1:0.01
blending_function = (factorial(np)/factorial(j)*factorial(np-j)).*(t.^j).*(1-t).^(np-j))
px = symsum((blending_function.*x(j+1),j,0,np-1);
py = symsum(((factorial(np)/factorial(j)*factorial(np-j)).*(t.^j).*(1-t).^(np-j)).*y(j+1),j,0,np-1);
title("Bezier Curve for cloud points")
grid on
grid minor
xlabel('postition in x');
ylabel('position in y');
legend('Actual curve','Bezier Curve');
%axis([0 4.2 0 3.2]);
Susmit Kumar Sahu
Susmit Kumar Sahu on 9 Jul 2020
Please help me rectifying now.

Sign in to comment.

Answers (1)

Devineni Aslesha
Devineni Aslesha on 22 Jul 2020
Hi Susmit
In the given code, the error is due to the presence of x(j+1) and y(j+1) that belongs to Class uint32. However, the Expression defining terms of series in symsum should be symbolic (Class: sym). Make sure what is the purpose of using x and y in your code and convert it to symbolic expression. If you remove x(j+1) and y(j+1), the code runs without any error.


Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!