How to make a curved line

lat1 = 81.9;
lat2 = 82;
long1 = -12;
long2 = 20;
[I1,J1] =  find(lat>=lat1 &lat<=lat2 & (long>=long1 & long<=long2));

The values obtained in I1 are [192,174,175,187,188,189] and in J1 are [215, 216, 216, 216, 216,216]

It is not giving any error but not giving the result either

xx = (I1(1):(I1(end)-I1(1))/2:I1(end));
yy = interp1(I1,J1,xx,'spline');
m_plot(I1,J1,'bs',xx,yy);

Answer 1

[David Goodmanson]

Your I1 data is not sorted, so I1(end) - I1(1) is not the entire span. Also, if it were sorted, setting the spacing as half the span in the xx = ( : : ) command means that xx will always have three points. You might consider creating xx with the linspace command.