hud.py 文件源码

def _compute_divisions(self, xi, xf):
        assert xf > xi
        dx = xf - xi
        size = dx
        ndiv = 5
        text_width = dx/ndiv/2

        def rint(x):
            return math.floor(x+0.5)

        dx_over_ndiv = dx / ndiv
        for n in range(5): # iterate 5 times to find optimum division size
            #/* div: length of each division */
            tbe = math.log10(dx_over_ndiv)#;   /* looking for approx. 'ndiv' divisions in a length 'dx' */
            div = pow(10, rint(tbe))#;  /* div: power of 10 closest to dx/ndiv */
            if math.fabs(div/2 - dx_over_ndiv) < math.fabs(div - dx_over_ndiv): #/* test if div/2 is closer to dx/ndiv */
                div /= 2
            elif math.fabs(div*2 - dx_over_ndiv) < math.fabs(div - dx_over_ndiv):
                div *= 2 #          /* test if div*2 is closer to dx/ndiv */
            x0 = div*math.ceil(xi / div) - div
            if n > 1:
                ndiv = rint(size / text_width)
        return x0, div