Cmp Name | Parameters | Description |
ccc | emdata mask: image mask int negative: If set, returns -1 * ccc product. Set by default so smaller is better |
Cross-correlation coefficient (default -1 * ccc) |
dot | emdata mask: image mask int negative: If set, returns -1 * dot product. Set by default so smaller is better int normalize: If set, returns normalized dot product (cosine of the angle) -1.0 - 1.0. |
Dot product (default -1 * dot product) |
dot.tomo | emdata ccf: The ccf image, can be provided if it already exists to avoid recalculating it bool norm: Whether the cross correlation image should be normalized. Default is false. float threshold: Threshold applied to the Fourier amplitudes of the ccf image - helps to correct for the missing wedge. int tx: The x location of the maximum in the ccf image. May be negative. Useful thing to supply if you know the maximum is not at the phase origin int ty: The y location of the maximum in the ccf image. May be negative. Useful thing to supply if you know the maximum is not at the phase origin int tz: The z location of the maximum in the ccf image. May be negative. Useful thing to supply if you know the maximum is not at the phase origin |
straight dot product with consideration given for the missing wedge - normalization is applied by detecting significantly large Fourier amplitudes in the cross correlation image |
frc | int ampweight: If set, the amplitude of 'this' will be used to weight the result (default=0) float maxres: Highest resolution to use in comparison (soft cutoff). Requires accurate A/pix in image. <0 disables. Default=10 float minres: Lowest resolution to use in comparison (soft cutoff). Requires accurate A/pix in image. <0 disables. Default=500 int nweight: Downweight similarity based on number of particles in reference (default=0) int snrweight: If set, the SNR of 'this' will be used to weight the result. If 'this' lacks CTF info, it will check 'with'. (default=0) int sweight: If set, weight the (1-D) average by the number of pixels in each ring (default=1) int zeromask: Treat regions in either image that are zero as a mask |
Computes the mean Fourier Ring Correlation between the image and reference (with optional weighting factors). |
optvariance | int debug: Performs various debugging actions if set. int invert: If set, 'with' is rescaled rather than 'this'. 'this' should still be the noisier image. (default=0) int keepzero: If set, zero pixels will not be adjusted in the linear density optimization. (default=1) int matchamp: Takes per-pixel Fourier amplitudes from self and imposes them on the target, but leaves the phases alone. (default=0) int matchfilt: If set, with will be filtered so its radial power spectrum matches 'this' before density optimization of this. (default=1) int radweight: Upweight variances closer to the edge of the image. (default=0) |
Real-space variance after density optimization, self should be noisy and target less noisy. Linear transform applied to density to minimize variance. |
phase | int ampweight: If set, the amplitude of 'with' will be used as a weight in the averaging'. (default=0) float maxres: Highest resolution to use in comparison (soft cutoff). Requires accurate A/pix in image. <0 disables. Default=10 float minres: Lowest resolution to use in comparison (soft cutoff). Requires accurate A/pix in image. <0 disables. Default=500 int snrfn: If nonzero, an empirical function will be used as a radial weight rather than the true SNR. (1 - exp decay)'. (default=0) int snrweight: If set, the SNR of 'this' will be used to weight the result. If 'this' lacks CTF info, it will check 'with'. (default=0) int zeromask: Treat regions in either image that are zero as a mask |
Mean phase difference |
quadmindot | int negative: If set, returns -1 * dot product. Default = true (smaller is better) int normalize: If set, returns normalized dot product -1.0 - 1.0. |
Caclultes dot product for each quadrant and returns worst value (default -1 * dot product) |
sqeuclidean | emdata mask: image mask int normto: If set, 'with' is normalized to 'this' before computing the distance int zeromask: If set, zero pixels in either image will be excluded from the statistics |
Squared Euclidean distance (sum(a - b)^2)/n. |