Bsoft function

img_ctf_calculate

Source:

src/img/img_ctf.c

Description:

Calculates a CTF complex image.

Algorithm: 

	Functions:

		angle = atan(y/x)

		s2 = x*x + y*y

		defocus_average = (defocus_max + defocus_min)/2

		defocus_deviation = (defocus_max - defocus_min)/2

		defocus = defocus_average + defocus_deviation*cos(2*(angle - astigmatism_angle))

		phase = 0.5*PI*lambda*lambda*lambda*Cs*s2*s2 - PI*lambda*defocus*s2;

		CTF = cos(phase) + i*sin(phase)

	Note: Defocus is positive for underfocus and negative for overfocus.

Arguments:

float defocus_avgaverage defocus (angstrom).
float defocus_devdefocus deviation (angstrom).
float ast_angleastigmatism angle (radians).
float voltaccelerating voltage (volts).
float Csspherical abberation (angstrom).
float amp_facamplitude contribution.
Vector3 sizenew image size.
Vector3 samplingnew image pixel size.

Returns:

Bimage* p new complex image.

Prototype:

Bimage* img_ctf_calculate(float defocus_avg, float defocus_dev, float ast_angle, float volt, float Cs, float amp_fac, Vector3 size, Vector3 sampling)

Functions used:

balloc

Other objects included:

struct Bimage
struct Bmarker
class Complex
constant M_PI

Generated by bdoc.pl on Mon Jun 15 11:47:46 2009

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