yacasInstall             package:Ryacas             R Documentation

_I_n_s_t_a_l_l _y_a_c_a_s _f_i_l_e_s _n_e_e_d_e_d _b_y _R_y_a_c_a_s

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

     Download the 'script.dat' and 'yacas.exe' files needed by
     'Ryacas'.

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

     yacasInstall(url = "http://ryacas.googlecode.com/files/yacas-1.0.63.zip",
        overwrite = FALSE)
     yacasFile(filename = c("yacas.exe", "scripts.dat", "R.ys"),
        slash = c("\", "/"))

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

     url: URL of a zip file containing  'yacas.exe' and 'scripts.dat'.

overwrite: If 'TRUE' then existing files are overwritten.

filename: Name of file whose full path is wanted.

   slash: slash style to use on output pathname.

     ...: Additional arguments passed to 'download.file'.  In most
          cases this is not used.

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

     'yacasInstall' downloads a zip file and extracts 'yacas.exe' and 
     'scripts.dat' installing them into  'yacasFile("yacas.exe")' and
     'yacasFile("scripts.dat")'.

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

     'yacasInstall' has no return value.

     'yacasFile' returns the full pathname of the indicated yacas file
     or the location where it would be if it were installed.  For
     'yacas.exe' this is the contents of the environment variable
     'YACAS_HOME' or if that is not defined then it is the folder
     'system.file(package = "Ryacas", "yacdir")'. For 'scripts.dat'
     this is the contents of the environment variable 'YACAS_SCRIPTS',
     or if that is not defined, it is the folder where 'yacas.exe' is
     located or would be located. For 'R.ys' this is the contents of
     the environment variable 'YACAS_INIT', or if that is not defined,
     it is located in 'system.file(package = "Ryacas", "yacdir")'. 
     Note that 'R.ys' is included with 'Ryacas' since it is a text file
      but 'scripts.dat' is not included since it is a binary file 
     which is why their default locations differ.

     'yacasCheck' returns '0' if the yacas files, 'yacas.exe' and
     'scripts.dat' were found in 'yacasFile("yacas.exe")' and
     'yacasFile("scripts.dat")',  '-1' if they were not found and '1'
     if they were found but have the wrong file size.  If the user
     specifies the 'YACAS_INVOKE_STRING' environment variable then it
     will not be able to perform the check in which case 'NA' is
     returned.

_N_o_t_e:

     These functions are for Windows systems only.  For other platforms
     these environment variables are not available and the user must
     install yacas manually prior to installing 'Ryacas'.

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

     ## Not run: 
     Sys.getenv("YACAS_INVOKE_STRING")
     Sys.getenv("YACAS_HOME")
     Sys.getenv("YACAS_SCRIPTS")
     system.file(package = "Ryacas", "yacdir")
     yacasFile("yacas.exe")
     yacasFile("scripts.dat")
     yacasInstall()
     ## End(Not run)

