Partial derivative of fct with respect to x, evaluated at (x, y).
fct
x
(x, y)
Partial derivative of fct with respect to y, evaluated at (x, y).
y
Value of fct(x, y).
fct(x, y)
Partial derivatives of fct with respect to fwhmX and fwhmY, in that order.
fwhmX
fwhmY
Partial derivative of
fctwith respect tox, evaluated at(x, y).