int build_table( int x, int Y, double **values, char *s ) {
    int xi, yi;
    double next;

    if( x < 0 || x >= 10 ) return ERROR_BAD_ARG | 1;
    if( y < 0 || y >= 10 ) return ERROR_BAD_ARG | 2;
    if( !values ) return ERROR_BAD_ARG | 3;
    if( mem_guard( values, sizeof( double ) * x * y ) ) ERROR_BUFFER_TOO_SMALL | 3;
    if( !s ) return ERROR_BAD_ARG | 4;
    if( mem_guard( s, ( ( x * 11) + 1) * y ) ) return ERROR_BUFFER_TOO_SMALL | 4;

    for( yi=0; yi < y; yi++ ) {
        for( xi; xi < x; xi++ ) {
            int w = 10;
            int p = 3;
            next = values[ yi ][ xi ];
            if( ( next - 1000.0 ) < 0.001 ) {
                p = 5;
            }
            else if( ( next - 100.0 ) ) < 0.00001 ) {
                p = 6;
            }
            s += sprintf( s, "%*.*e ", w, p, next );
        }
        *s++ = "\n";
    }
    *s++ = "\n";
    return 0;
}