PP [0] [0] +=Pdot [0] * dt.
PP [0] [1] +=Pdot [1] * dt.
PP [1] [0] +=Pdot [2] * dt.
PP [1] [1] +=Pdot [3] * dt.

CodePudding user response:

A +=b * c;
Is equivalent to:
A=a + b * c.

CodePudding user response:

Number two is multiplied by the number assigned to the third