geolocation - Matlabs ellipse hours calc -

i make sundial simulator , draw ellipse , have draw hours on ellipse. every our specified by:

x = * sin(t); y = b * cos(t); 

where:

a- length of longer semi-axis b- length of smaller semi-axis t- hour in degrees ( 1 hour == 15 degrees) 

i wrote function in matlab:

function [hx,hy] = calchourcoords(ra,rb)     %input:     %ra, rb length of semi-axis in ellipse     %output:     %hx, hy coords of hour's plot     hourangle = 15*180/pi;     step = 0;     i=1:1:24        hx(i)= ra * sin(step);        hy(i)= rb * cos(step);        step = step+hourangle;     end end 

finally pic: my ellipse , hours points

but should looks like: correct hour place's

ellipse correct ( draw version other latitude ).

maybe me ?

sorry english :)

edit

i repair - convert degrees radians.

edit2

i change source code fyi

function [hx,hy] = calchourcoords(ra,rb)     %input:     %ra, rb length of semi-axis in ellipse      %output:     %hx, hy coords of hour's plot     hourangle = 15*pi/180;     step = 0;        i=1:1:24            hx(i)= ra * sin(step);            hy(i)= rb * cos(step);            step = step+hourangle;        end end