十進角
D = trunc  ( D dec , 0 ) M = trunc  ( 60 × | D dec − D | , 0 ) S = 3600 × | D dec − D | − 60 × M {\displaystyle {\begin{aligned}\mathrm {D} &=\operatorname {trunc} (\mathrm {D} _{\text{dec}},0)\\\mathrm {M} &=\operatorname {trunc} (60\times |\mathrm {D} _{\text{dec}}-\mathrm {D} |,0)\\\mathrm {S} &=3600\times |\mathrm {D} _{\text{dec}}-\mathrm {D} |-60\times \mathrm {M} \end{aligned}}}
ここで、 | D d e c − D | {\textstyle \mathrm {\left\vert D_{dec}-D\right\vert } } は、 D d e c − D {\textstyle \mathrm {D_{dec}-D} } の絶対値、 t r u n c {\textstyle \mathrm {trunc} } は切り捨て関数を表す。