#230 closed defect (fixed)
psMinimizeChi2LMGauss2D()
| Reported by: | Owned by: | Paul Price | |
|---|---|---|---|
| Priority: | high | Milestone: | |
| Component: | PSLib SDRS | Version: | unspecified |
| Severity: | normal | Keywords: | |
| Cc: |
Description
Can you specify the formula for a 2-D Gaussian?
Change History (5)
comment:1 by , 22 years ago
| Resolution: | → fixed |
|---|---|
| Status: | new → closed |
comment:2 by , 22 years ago
| Resolution: | fixed |
|---|---|
| Status: | closed → reopened |
How does "the normilzation" fit in? Also, do you have a preference as to how
these values are to be stored in the "params" parameter to the Gauss2D function,
or should I choose an arbitrary order?
comment:3 by , 22 years ago
| Resolution: | → fixed |
|---|---|
| Status: | reopened → closed |
The "norm" parameter in the equation above corresponds to the normalisation.
Suggest order:
norm
x0
y0
sigma_u
sigma_v
theta
comment:4 by , 22 years ago
| Keywords: | VERIFIED added |
|---|
Closing subsequent to release of SDRS-08, ADD-07.
comment:5 by , 22 years ago
| Keywords: | VERIFIED removed |
|---|
Note:
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We first perform a rotation:
u = - (x-x0)*cos(theta) + (y-y0)*sin(theta)
v = (x-x0)*cos(theta) + (y-y0)*sin(theta)
Here u is the major axis, and v is the minor axis, x0,y0 is the centre, and
theta is the position angle.
Then the flux is
flux = norm * exp(-( u*u/2.0/sigmau/sigmau + v*v/2.0/sigmav/sigmav)
)/2.0/pi/sigmau/sigmav
Here sigmau and sigmav are the widths of the major and minor axes.