Information processor

In an information processing apparatus for conducting an affine transformation representative of ( x ' y ' z ' ) = A ⁡ ( x y z ) + ( t 1 t 2 t 3 ) , ⁢ a ⁢ ⁢ matrix A ' = ( a 11 ' a 12 ' a 13 ' a 21 ' a 22 ' a 23 ' a 31 ' a 32 ' a 33 ' ) = lambda ⁢ ⁢ A = ( lambda ⁢ ⁢ a 11 lambda ⁢ ⁢ a 12 lambda ⁢ ⁢ a 13 lambda ⁢ ⁢ a 21 lambda ⁢ ⁢ a 22 lambda ⁢ ⁢ a 23 lambda ⁢ ⁢ a 31 lambda ⁢ ⁢ a 32 lambda ⁢ ⁢ a 33 ) obtained by multiplying a matrix A for the affine transformation by lambda(0) is stored in a memory section in advance. In case of conducting calculation processing for transforming coordinates (x,y,z)t into coordinates (x',y',z')t by means of the affine transformation, A' and a matrix (t1,t2,t3)t are read from the memory section, x'=(a'11*x+a'12*y+a'13*z)/lambda+t1; y'=(a'21*x+a'22*y+a'23*z)/lambda+t2; z'=(a'31*x+a'32*y+a'33*z)/lambda+t3; are calculated, and the coordinates (x',y',z')t are obtained.