It is possible to load data from a file for plots with PSTricks in TeX. According to the PSTricks manual all that is needed is a file with a list of coordinate pairs delimited by curly braces , parentheses, commas.
One easy solution is to use the write command from scilab. Define the following function:

function pstrickswrite2d(filename,data_matrix)
//Author: Panagiotis Chatzichrisafis
//Date: 25.01.2015
//The function pstrickswrite2d(filename,data_matrix) has two inputs: 
//: The path and the filename which shall be used to write 
//            formated output for PSTricks 
//: The matrix containing the data to be written into the file provided by
//                argument.
//The output written to the  file has a format which is suitable for 
//the TeX PSTricks package fileplot or dataplot commands.  
    _max_num_ = max(abs(data_matrix));
    _num_integer_digits_ = ceil(log10(_max_num_)); 
    _num_format_(1) ='F';
    // add number of integer digits and decimal digits plus 2 for sign information
    _num_format_(2) = string(_num_integer_digits_+_num_decimal_places_+2); 
    _num_format_(3) ='.'; 
    _num_format_(4) = string(_num_decimal_places_);
    _num_format_ =strcat(_num_format_);
    _format_(1)   ='( ''{'' '   ;
    _format_(2)   = _num_format_; 
    _format_(3)   = ', '','' '  ;
    _format_(4)   = _num_format_; 
    _format_(5)   = ' ''}'' )'  ;

and load it into the scilab workspace.