Coordinate system

 Author Message nakayama Distinguished Member Group: Forum Members Posts: 64, Visits: 374 Hi, Dave,This maybe an old question. I wish to calculate the coordinate of  (a,b) in pixels under the screen resolution of (1960,1200). The angle between is 10 degree.Is there a formula I could refer to? I used something like this but does work./ circle_a=1px*(expressions.circle_x+300*cos(0.174533))/ circle_b=1px*(expressions.circle_y+300*sin(0.174533))Thank you nakayama Distinguished Member Group: Forum Members Posts: 64, Visits: 374 +xnakayama - 11/5/2019Hi, Dave,This maybe an old question. I wish to calculate the coordinate of  (a,b) in pixels under the screen resolution of (1960,1200). The angle between is 10 degree.Is there a formula I could refer to? I used something like this but does work./ circle_a=1px*(expressions.circle_x+300*cos(0.174533))/ circle_b=1px*(expressions.circle_y+300*sin(0.174533))Thank you *(960, 1000) is (x,y) Dave Supreme Being Group: Administrators Posts: 9.9K, Visits: 49K +xnakayama - 11/6/2019+xnakayama - 11/5/2019Hi, Dave,This maybe an old question. I wish to calculate the coordinate of  (a,b) in pixels under the screen resolution of (1960,1200). The angle between is 10 degree.Is there a formula I could refer to? I used something like this but does work./ circle_a=1px*(expressions.circle_x+300*cos(0.174533))/ circle_b=1px*(expressions.circle_y+300*sin(0.174533))Thank you *(960, 1000) is (x,y)/ theta = (values.angle)*(m_pi/180)/ deltax = values.radius*cos(expressions.theta)/ deltay = values.radius*sin(expressions.theta)/ a = values.x+expressions.deltax/ b = values.y+expressions.deltay/ x = 960px/ y = 1000px/ radius = 300px/ angle = -10/ shape = circle/ size = (40px, 40px)/ color = blue/ hposition = values.x/ vposition = values.y/ shape = circle/ size = (40px, 40px)/ color = red/ hposition = expressions.a/ vposition = expressions.b/ stimulusframes = [1=xy, ab]/ validresponse = (57)