float xmin, xmax, ymin, ymax;
double xmin, xmax, ymin, ymax;
    void plot1( int do_test )    {        int i;        float xmin, xmax, ymin, ymax;        for( i=0; i < 60; i++ )        {            x[i] = xoff + xscale * (i + 1) / 60.0f;            y[i] = yoff + yscale * (float) Math.pow(x[i], 2.f);        }        xmin = x[0];        xmax = x[59];        ymin = y[0];        ymax = y[59];        for( i=0; i < 6; i++ )        {            xs[i] = x[i * 10 + 3];            ys[i] = y[i * 10 + 3];        }    // Set up the viewport and window using PLENV. The range in X is 0.0 to    // 6.0, and the range in Y is 0.0 to 30.0. The axes are scaled separately    // (just = 0), and we just draw a labelled box (axis = 0).        pls.col0(1);        pls.env( xmin, xmax, ymin, ymax, 0, 0 );        pls.col0(2);        pls.lab( "(x)", "(y)", "#frPLplot Example 1 - y=x#u2" );    // Plot the data points.        pls.col0(4);        pls.poin( 6, xs, ys, 9 );    // Draw the line through the data.        pls.col0(3);        pls.line(60, x, y);    }