getXref               package:biomaRt               R Documentation

_G_e_t _c_r_o_s_s _r_e_f_e_r_e_n_c_e _i_n _E_n_s_e_m_b_l

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

     This powerful function retrieves any cross reference in Ensembl

_U_s_a_g_e:

     getXref(id, from.species, to.species, from.xref, to.xref, mart)

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

      id: any identifier

from.xref: type of identifier, value should correspond to results of
          getPossibleXrefs function

 to.xref: type of identifier, value should correspond to results of
          getPossibleXrefs function

from.species: species of which the id is from.  Accepted values for
          species can be retrieved with the function getSpecies()

to.species: species in which you want to find the homologs.  Accepted
          values for species can be retrieved with the function
          getSpecies()

    mart: object of class Mart, containing connections to the BioMart
          databases.  You can create such an object using the function
          useMart.

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

     Sean Davis, Steffen Durinck, <URL:
     http://www.esat.kuleuven.ac.be/~sdurinck>

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

     if(interactive()){
     mart <- useMart("ensembl",mysql=TRUE)

     #starting from an affy id of chip hg_u95av2 and id 1939_at, give me corresponding affy identifiers on the affy mouse chip mouse430_2

     xref = getXref(id="1939_at", from.species="hsapiens", to.species = "mmusculus", from.xref ="affy_hg_u95av2", to.xref="affy_mouse430_2",mart=mart)
     show(xref)

     martDisconnect(mart = mart)
     }

