locationTest             package:fBasics             R Documentation

_T_w_o _S_a_m_p_l_e _L_o_c_a_t_i_o_n _T_e_s_t_s

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

     Tests if two series differ in their distributional location
     parameter.

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

     locationTest(x, y, method = c("t", "kw2"), 
         title = NULL, description = NULL) 

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

    x, y: numeric vectors of data values. 

  method: a character string naming which test should be applied. 

   title: an optional title string, if not specified the inputs data 
          name is deparsed. 

description: optional description string, or a vector of character
          strings. 

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

     The 'method="t"' can be used to determine if the two sample  means
     are equal for unpaired data sets. Two variants are used, assuming
     equal or unequal variances. 

     The 'method="kw2"' performs a Kruskal-Wallis rank sum  test of the
     null hypothesis that the central tendencies or medians of  two
     samples are the same. The alternative is that they differ.  Note,
     that it is not assumed that the two samples are drawn from the 
     same distribution. It is also worth to know that the test assumes 
     that the variables under consideration have underlying continuous 
     distributions.

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

     In contrast to R's output report from S3 objects of class
     '"htest"' a different output report is produced. The classical
     tests presented here return an S4 object of class '"fHTEST"'. The
     object contains the following slots:

   @call: the function call.   

   @data: the data as specified by the input argument(s). 

   @test: a list whose elements contail the results from the
          statistical test. The information provided is similar to a
          list object of class '"htest"'. 

  @title: a character string with the name of the test. This can be 
          overwritten specifying a user defined input argument. 

@description: a character string with an optional user defined
          description.  By default just the current date when the test
          was applied will be returned. 

statistic: the value(s) of the test statistic. 

 p.value: the p-value(s) of the test. 

parameters: a numeric value or vector of parameters. 

estimate: a numeric value or vector of sample estimates. 

conf.int: a numeric two row vector or matrix of 95 

  method: a character string indicating what type of test was
          performed. 

data.name: a character string giving the name(s) of the data. 

_N_o_t_e:

     Some of the test implementations are selected from R's 'ctest' 
     package.

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

     R-core team for hypothesis tests implemented from R's  package
     'ctest'.

_R_e_f_e_r_e_n_c_e_s:

     Conover, W. J. (1971); _Practical nonparametric statistics_, New
     York: John Wiley & Sons.

     Lehmann E.L. (1986);  _Testing Statistical Hypotheses_,  John
     Wiley and Sons, New York.

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

     ## rnorm - 
        # Generate Series:
        x = rnorm(50)
        y = rnorm(50)
       
     ## locationTest -
        locationTest(x, y, "t")
        locationTest(x, y, "kw2")

