itsArith                 package:its                 R Documentation

_A_r_i_t_h_m_e_t_i_c _M_e_t_h_o_d_s _f_o_r _I_r_r_e_g_u_l_a_r _T_i_m_e-_S_e_r_i_e_s _O_b_j_e_c_t_s

_D_e_s_c_r_i_p_t_i_o_n:

     Arithmetic methods for objects of class '"its"'.

_A_r_g_u_m_e_n_t_s:

      e1: its object

      e2: its object

_D_e_t_a_i_l_s:

     Date matching is performed then the arithmatic is done on the
     intersection of the dates of the two arguments. The arithmetic
     operators return numeric vectors containing the result of the 
     element-by-element operations.

     Note that the matrix multiplication operator,  and the result of a
     matrix multiplication is a matrix, not an '"its"'. The resulting
     matrix can be converted back to its using the function its()  -
     see examples.

_V_a_l_u_e:

     The returned object is an object of class '"its"', having the same
     number of columns as the two arguments, however, the number of
     rows will be the length of the intersection of the dates of the
     two arguments.

_A_u_t_h_o_r(_s):

     Giles Heywood

_S_e_e _A_l_s_o:

     'ts', 'POSIXct', 'itsFile', 'itsLags' 'itsJoin' 'itsTimes'
     'itsSubset' 'itsFin' 'itsDisp' 'itsInfo' 'itsCumdif' 'itsInterp'

_E_x_a_m_p_l_e_s:

     b <- newIts(1:30,ncol=3)
     c <- newIts(1:10,ncol=3)[1:5,]
     b+c
     b+b-2*b
     b/b
     b%*%diag(ncol(b))
     its(b%*%diag(ncol(b))) 

