|BP RP 3||[Back Projection - 3D, iterative, Richardson, constrained ||*]|
|BP CG||[Back Projection - 3D, Iterative, Conjugate Gradients ||*]|
|BP 3F||[Back Projection - 3D, Interpolated in Fourier space ||*]|
|BP 3D||[Back Projection - 3D, using Euler angles ||]|
|BP W2||[Back Projection - 2D, filtered, weighted ||]|
.TEMPLATE FOR IMAGE FILE: PROJ***
[Enter template for projection image input files.]
.FILE NUMBERS OR SELECTION DOC. FILE NAME: 1-700
[Enter image file numbers or the name of a document file which contains the image file numbers in its first register column.]
.RADIUS OF RESTORED OBJECT: 23
[Enter radius of reconstructed object in pixels (smaller than the volume size). The reconstruction is calculated inside the sphere only.]
.ANGLES DOC FILE: ANGLESDOC
[Enter name of the document file which contains Eulerian angles: psi, theta, and phi in the first three registers columns. These angles specify the projection directions.]
.SYMMETRIES ANGLES DOC FILE: ANGSYMDOC
[Enter * if the structure has no symmetries.
Otherwise, enter the name of the document file containing Eulerian angles defining symmetries (psi, theta, phi). The angles should be such that when used in operation 'RT 3D' they transform the volume into itself. The identity operation (angles 0,0,0) MUST be included. The symmetries will be internally enforced on the volume. The reconstruction in this case is calculated as though the projections were multiplied as many times as there are symmetries.]
.RECONSTRUCTED VOLUME FILE: VOLUME1001
[Enter name for the output file.]
.LAMBDA, CORRECTION LIMIT: 1.0e-4, 0.0
[Lambda determines the weight of corrections. Too small a value results in long time of calculations; too large value will terminate the iterations too soon. (Note #2).
Correction limit can be used to terminate the iterations. When the squared correction of the structure becomes smaller than the preset value, the iterations are terminated. When correction limit is set to zero, it will not be used to terminate the program. Iteration limit will be used instead.]
.ITERATION LIMIT, MODE: 25, 8
[Program will terminate after number of iterations given.
Mode determines the constraint(s) used:
0 - No constraints.
1 - Smoothing.
2 - Min constraint.
3 - Smoothing & min constraints.
4 - (No mode 4)
5 - Max constraint.
6 - Smoothing & max constraints.
7 - Min & max constraint.
8 - Smoothing, min, & max constraints.
Any combination of constraints can be used. The mode value should be the sum of any single modes, for example mode=7 activates both min and max constraints, while mode=8 uses all three of them. Constraints are ignored if mode=0, but dummy values should still be entered on the next two lines.]
.MINIMUM, MAXIMUM: 1.77, 1.90
[Values of min and max constraints: i.e., the max and min values of the 2D projection data set. Constraints are ignored if mode=0, but dummy values must still be entered.]
.SMOOTHING CONSTANT (0-0.999): 0.9994
[Smoothing constant determines relative weight of the low-pass filtration. See note #4. Constraints are ignored if mode=0, but a dummy value must still be entered.]
|Lambda||Smoothing constant||Res'n limit (pixels)|