**PURPOSE**- Rotates an image/volume around specified center by specified angles. Can choose type of interpolation (which affects accuracy) and corner values. This operation replaces: 'RT C', 'RT 3A', and 'RT 3AS' Example.

**SEE ALSO****ROT**[ROTate image/volume around center by specified angle(s)] **ROT L**[ROTate volume around specified line] **RT SF**[Rotate and Shift - image, Fourier based spline interpolation ||] **RT SQ**[Rotate and Shift - image, Quadratic interpolation ||]

**USAGE**- .OPERATION: ROT A

- .INPUT FILE: PIC001

[Enter name of file to be rotated.].OUTPUT FILE: ROT001

[Enter name of file where the rotated image/volume is to be stored.] - If input is a image SPIDER asks:
.ROTATION ANGLE: 10.5

[Enter the rotation angle (in degrees). Positive rotations appear counter-clockwise.].X & Y CENTER OFFSETS: 12, 60.5

[Enter offset between SPIDER image center and the desired rotation point.]- If input is a volume SPIDER asks:

.PHI, THETA, & PSI: 10.5, 13.7, 45.8

[Enter the Eulerian angles for rotation (in degrees): Phi (around Z), Theta (around Y), and Psi (around Z).].X, Y & Z CENTER OFFSETS: 12, 60.5

[Enter offset between SPIDER image center and the desired rotation point.].LINEAR, QUADRATIC, OR FBS INTERPOLATION (L,Q,F): F

[Linear interpolation is faster but inferior to quadratic interpolation. Fourier-based spline interpolation gives best interpolation accuracy. Image interpolation is bi-linear, bi-quadratic or FBS. Volume interpolation is tri-linear, tri-quadratic or FBS.].UNROTATED, AVG, MIN, OR SPECIFIED CORNERS (U,A,M,2.5)',

[Sets value for corner values, can input a numerical value or use image/volume specific values.]

**NOTES**

- Program reads volume into memory - huge volumes may not fit.
- For volumes positive rotations are clockwise.
- Rotation matrix used:
R = R(psi) * R(theta) * R(phi) c s 0 c 0 -s c s 0 -s c 0 * 0 1 0 * -s c 0 0 0 1 s 0 c 0 0 1

- Implemented by P. Penczek, A. Leith, & G. Kishchenko.

**SUBROUTINES**- ROTATES, ROTATES3Q, ROTATES3L, RTSQ, RTSF, FBS2, FBS3

**CALLER**- UTIL3

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