HARKinterpolation.py 文件源码

def _derX(self,x,y,z):
        '''
        Returns the derivative with respect to x of the interpolated function
        at each value in x,y,z. Only called internally by HARKinterpolator3D.derivativeX.
        '''
        if _isscalar(x):
            z_pos = max(min(np.searchsorted(self.z_list,z),self.z_n-1),1)
            alpha = (z - self.z_list[z_pos-1])/(self.z_list[z_pos] - self.z_list[z_pos-1])
            dfdx = (1-alpha)*self.xyInterpolators[z_pos-1].derivativeX(x,y) + alpha*self.xyInterpolators[z_pos].derivativeX(x,y)
        else:
            m = len(x)
            z_pos = np.searchsorted(self.z_list,z)
            z_pos[z_pos > self.z_n-1] = self.z_n-1
            z_pos[z_pos < 1] = 1
            dfdx = np.zeros(m) + np.nan
            if x.size > 0:
                for i in xrange(1,self.z_n):
                    c = z_pos == i
                    if np.any(c):
                        alpha = (z[c] - self.z_list[i-1])/(self.z_list[i] - self.z_list[i-1])
                        dfdx[c] = (1-alpha)*self.xyInterpolators[i-1].derivativeX(x[c],y[c]) + alpha*self.xyInterpolators[i].derivativeX(x[c],y[c]) 
        return dfdx