function dhp=drehmatrix(dhp) 

 dhp = [cos(dhp.beta)    -sin(dhp.beta)*cos(dhp.delta)     sin(dhp.beta)*sin(dhp.delta)    dhp.d*cos(dhp.beta); 
       sin(dhp.beta)     cos(dhp.beta)*cos(dhp.delta)    -cos(dhp.beta)*sin(dhp.delta)    dhp.d*sin(dhp.beta); 
               0                   sin(dhp.delta)                     cos(dhp.delta)                    dhp.s; 
               0                   0                                    0                                   1]; 
end