MATLAB: I have some problem when plotting the graph, anyone can help? Thanks

for loop

This is my code

for x = -10:10
    y = 2^(0.4*x)+5
    plot(x,y,'g')
end

Hi,

You need to store y first.

x = -10:10;
for i = 1:numel(x)
    y(i) = 2^(0.4*x(i))+5
end
plot(x,y,'g')

k = importdata ('data.txt') ;

The problem is that you are encountering floating point approximation error.

If you do the comparison:

x_error = x(4) - 0.6
x_error =
   111.0223e-018

The solution is to allow for the tolerance. The easiest way is to change your ‘idx3’ assignment to:

idx3=find((x<=0.6),1,'last')

which works.