findFC              package:factDesign              R Documentation

_A _f_u_n_c_t_i_o_n _t_o _f_i_n_d _t_h_e _f_o_l_d _c_h_a_n_g_e _b_e_t_w_e_e_n _t_w_o _e_x_p_e_r_i_m_e_n_t_a_l _c_o_n_d_i_t_i_o_n_s _i_n _a _f_a_c_t_o_r_i_a_l _e_x_p_e_r_i_m_e_n_t _b_a_s_e_d _o_n _t_h_e _l_i_n_e_a_r _m_o_d_e_l _p_a_r_a_m_e_t_e_r _e_s_t_i_m_a_t_e_s.

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

     'findFC' constructs a point estimate of fold change using the
     linear model coefficients in an lm object.

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

     findFC(model, lambdaNum, lambdaDenom)

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

   model: An lm object.

lambdaNum: A numeric vector of coefficients for the parameters to be
          used in the numerator of the fold change estimate. 

lambdaDenom: A numeric vector of coefficients for the parameters to be
          used in the denominator of the fold change estimate. 

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

     A point estimate of the fold change between the experimental
     conditions specified in the lambdaNum and lambdaDenom vectors.

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

     Denise Scholtens

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

     'par2lambda', 'findFClog'

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

     data(estrogen)
     ES <- pData(estrogen)[["ES"]]
     TIME <- pData(estrogen)[["TIME"]]   
     fit <- lm(exprs(estrogen)[6,] ~ ES + TIME + ES*TIME)
     betaNames <- names(fit[["coef"]])
     betas <- list(c("(Intercept)","ESP","TIME48h","ESP:TIME48h"),
                                             c("(Intercept)","ESP"))
     coefs <- list(c(1,1,1,1),c(1,1))
     lambda <- par2lambda(betaNames,betas,coefs)
     findFC(fit,lambda[1,],lambda[2,])

