**PURPOSE**- Creates a model image. The following options are
available:

1. Constant density (Blank)

2. Circle of specified radius

3. Diagonal sine wave of frequency (2,2)

4. Test pattern consisting of specified sine waves

5. Gaussian circular density distributions

6. Random density with uniform distribution

7. Random density with Gaussian distribution

8. Diagonal density wedge

Example.

**SEE ALSO****MO 3**[Create Model volume] **BL**[Create Blank image/volume] **PT**[Create Pattern or mask image] **PP**[Put Points in image - from terminal] **PP L**[Put Points in image - from Document file Listing]

**USAGE**- .OPERATION: MO

- .OUTPUT FILE: MOD001

[Enter the name of the output file.].DIMENSIONS (NX,NY): 64,64

[Enter the dimensions of the image in the output file.]

[Following pattern menu appears.]

MENU:

B BLANK, CONSTANT DENSITY C CIRCLE G GAUSSIAN CIRCLE/ELLIPSE G1 1ST ORDER GAUSSIAN CIRCLE/ELLIPSE (0...1) G2 2ND ORDER GAUSSIAN CIRCLE/ELLIPSE (0...1) G3 3RD ORDER GAUSSIAN CIRCLE/ELLIPSE (0...1) R RANDOM DENSITY PATTERN S SINE WAVES T TWO SINE WAVES W DIAGONAL DENSITY WEDGE .OPTION (B/C/G/G1/G2/G3/R/S/T/W): T

[Enter the desired pattern option.] - For
**Option "B" -Blank Image**

.DENSITY: 12.0

[Enter the desired intensity for the image.]- For
**Option "C" - Circle**

.RADIUS (FLOATING POINT): 12.0

[Enter the desired radius of the circle. Any floating point number between 0.0 and SQRT[(NX/2)**2 + (NY/2)**2] may be specified.][The output file will then contain a circle of specified radius filled with pixel values of 1.0, and a blank (pixel value 0.0) background. Circle will be placed at SPIDER image center.]

- For Options
**"G" - Gaussian distribution**

.CENTER COORDINATES X,Y (OR <CR> FOR IMAGE CENTER): 12, 23.12

.CHARACTARISTIC RADII IN X & Y: 4, 2

[Enter the radii for Gaussian function this is approximately the radius at which the value is half height. A 2D Gaussian density distribution is created. The normalization is such that the sum of all the pixel densities is equal to one. Note that such normalization is**not**usefull in creating a mask. Use 'G1,G2,G3' for typical mask creation.- For Options
**"G1, G2, G3" - Gaussian distribution (used for masking)** - Creates a circular/eliptical Gaussian density distribution normalized such that the
**maximum**pixel density equals 1.0.

'G2' and 'G3' are super-Gaussian masks of order 2 and 3 with squared or cubed Gaussian falloffs and are generally better than 'G1' for most uses. Their densities are in the form:

where n is the order of Super-Gaussian, and a and b are the semi-principal axes of the ellipse..CENTER COORDINATES X & Y (or <CR> FOR IMAGE CENTER): 12, 23.12

.CHARACTARISTIC RADII IN X & Y: 4, 2

[Enter the radii (same as standard deviations) for Gaussian function. Controls radius of mask.] - For
**Option "R" - Random**

.GAUSSIAN DISTRIBUTED? (Y/N): N

[For 'N' a random image with values uniformly distributed between 0 and 1 is generated. If 'Y' is specified, SPIDER will ask:].MEAN AND STANDARD DEVIATION OF GAUSSIAN DIST.: 0.0, 0.35

[Enter the mean value and standard deviation of the Gaussian distribution for random numbers to be generated.]- For
**Option "S" - Sine waves**

.NUMBER OF SINE WAVES: 2

[Enter the number of sine waves to be added together. The maximum is 20.].I=1 AMPLITUDE, PHASE, SP. FREQUENCY (KX,KY): 1.0,45.,1,10

[Enter the amplitude and phase of the first sine wave, and its X and Y frequencies, respectively.].I=2 AMPLITUDE, PHASE, SP. FREQUENCY (KX,KY): 2.5,90., -2,5

[Enter the relative amplitude and phase of the second sine wave, and its X and Y frequencies, respectively.][The output file will now contain an image of the specified size, which is the sum of two sine waves, of specified amplitudes and phases, one of X-frequency 1 and Y-frequency 10, and the other of X-frequency -2 and Y-frequency 5. Note that the amplitudes and phases must be given as floating point numbers.]

- For
**Option "T" - TEST** - [The output file will contain a test sine wave of specified size and spatial frequency: (2,2), i.e. a diagonally-running sine wave with two full periods. Intensity is: -1.0... 1.0 ]

- For
**Option "W" - Wedge** - The output file will contain a diagonal density wedge of specified size with intensity 0.0 ... 1.0. Maximum (1.) is in upper left corner. Minimum (0.0) is in lower right corner.]

**SUBROUTINES**- MODEL, BLANK

**CALLER**- UTIL1

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